Water Heater Recommendations?

[jeromedawg]

Hey all,

Looking for recommendations on a new water heater - ours is rusting out and there's moisture/wet spots on the inner tank. Pilot light went out earlier so I noticed all this when I re-lit.

The plumber who installed a new water heater at my parents' place in the Bay Area says the newer Rheem water heaters aren't very reliable. I don't even know what he installed at their place but will find out soon.

Anyone have recommendations on a reliable 50 gallon natural gas tank heater? AO Smith? https://www.lowes.com/pd/A-O-Smith-Signature-Premier-50-Gallon-Tall-12-Year-Limited-Natural-Gas-Water-Heater/1000213585 ?


TIA!

[lthenderson]

Me personally, I just go with whatever brand my local plumber recommends and has on stock. They replace them all the time so have a better sense of reliability than I do when I only have to deal with this issue once every 15 years or so. I have had a variety of water heaters and never really had any issues with them beyond eventually rusting out.

[Fishindude]

Me personally, I just go with whatever brand my local plumber recommends and has on stock. They replace them all the time so have a better sense of reliability than I do when I only have to deal with this issue once every 15 years or so. I have had a variety of water heaters and never really had any issues with them beyond eventually rusting out.

Good advice here ..... and there is nothing wrong with Rheem water heaters.

[jeromedawg]

Me personally, I just go with whatever brand my local plumber recommends and has on stock. They replace them all the time so have a better sense of reliability than I do when I only have to deal with this issue once every 15 years or so. I have had a variety of water heaters and never really had any issues with them beyond eventually rusting out.

Thanks!

I got in touch with a couple contractors who gave me specific models they'd recommend for installation and pricing. They pretty much said the big box store Rheems and other water heaters are not that great and you want to stick with a contractor grade water heater.

Anyway, they recommended Rheem and Bradford:
Rheem Model# PROG50-38U-RH60-EC1 (6yr warranty)
Bradford White Model# URG250T6N (6yr warranty)

Rheem Model #  ProG 50-38u-RH62-EC1 (6yr warranty)

I'm planning to just have the contractors install this just because of the heavy-lifting, haul-away and my time and lack of familiarity (and desire) to do all this. The two quotes I've received via Yelp are $1295 (+$195 to extend to a 10 yr warranty) and then the other is $1450 (with the 6yr warranty). All the other plumbers want me to call them back or schedule appointments for them to come out and give quotes, which I guess is OK but a bit tedious... I may just have one or two swing by.

[Fishindude]

Sounds like you are doing OK.   Had mine replaced with a new 50 gal unit just a few months ago and price was within $100 of your quote.

FYI - Modern water heaters don't last as long as they did in our parents day.   If you have a water heater older than 15 years it's on borrowed time, and would probably be a good idea to schedule having it replaced, rather than dealing with a failure at some inopportune time.   Seems like stuff like this always pukes on you on a Sunday afternoon of a holiday weekend.

[jeromedawg]

Sounds like you are doing OK.   Had mine replaced with a new 50 gal unit just a few months ago and price was within $100 of your quote.

FYI - Modern water heaters don't last as long as they did in our parents day.   If you have a water heater older than 15 years it's on borrowed time, and would probably be a good idea to schedule having it replaced, rather than dealing with a failure at some inopportune time.   Seems like stuff like this always pukes on you on a Sunday afternoon of a holiday weekend.

yep, the guy who quoted me that price is having his tech come do a pre-inspection to double check since he has one in the area. Since he's been responsive and up-front about the cost, and it seems like a reasonable cost, along with very good recent Yelp reviews, I'll probably just go with these guys. I agree though - would rather get this replaced than have it crap out on us at the worst possible time (in which case, any time something like this craps out is gonna be the worst possible time lol)

[Papa bear]

Sounds like you are doing OK.   Had mine replaced with a new 50 gal unit just a few months ago and price was within $100 of your quote.

FYI - Modern water heaters don't last as long as they did in our parents day.   If you have a water heater older than 15 years it's on borrowed time, and would probably be a good idea to schedule having it replaced, rather than dealing with a failure at some inopportune time.   Seems like stuff like this always pukes on you on a Sunday afternoon of a holiday weekend.

Have you had any luck with changing out the sacrificial anodes? I’ve never done it so have no data points.  I’ve just basically replaced whole units whenever they go bad. Had a few over 15 years, but most have been in the 10-15 range. 

I’m hoping to keep my personal residence tank in better shape as its a fancy hybrid heat pump unit and not one of the $400 gas units that I’ve got at the rentals.


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[Fishindude]

Have you had any luck with changing out the sacrificial anodes? I’ve never done it so have no data points.  I’ve just basically replaced whole units whenever they go bad. Had a few over 15 years, but most have been in the 10-15 range. 

I’m hoping to keep my personal residence tank in better shape as its a fancy hybrid heat pump unit and not one of the $400 gas units that I’ve got at the rentals.

Kind of an unrelated answer to this ....
Soon as my water heater was replaced, we started noticing our hot water in the shower smelled a little bad, kind of egg water like.    Called the plumber that installed it and asked if there is any possibility that he somehow bypassed the water softener when he installed the new water heater and / or possibly shut off the softener.   

He says, no .... but I'll be out to check it out and I think I know what it is.
He explained the sacrificial anode thing to me and said that rod holds the impurities from your water inside the tank, rather than the impurities clinging to the tank walls.   It's supposed to make the tanks last longer.
His fix was to simply remove and dispose of the sacrificial anode and plug the hole where it inserts.   Said he has done this quite a bit, for the same issue.

So, I suppose my water heater may not last quite as long without it, but at least the water smells clean now.   I'm fine with that.

[jeromedawg]

Have you had any luck with changing out the sacrificial anodes? I’ve never done it so have no data points.  I’ve just basically replaced whole units whenever they go bad. Had a few over 15 years, but most have been in the 10-15 range. 

I’m hoping to keep my personal residence tank in better shape as its a fancy hybrid heat pump unit and not one of the $400 gas units that I’ve got at the rentals.

Kind of an unrelated answer to this ....
Soon as my water heater was replaced, we started noticing our hot water in the shower smelled a little bad, kind of egg water like.    Called the plumber that installed it and asked if there is any possibility that he somehow bypassed the water softener when he installed the new water heater and / or possibly shut off the softener.   

He says, no .... but I'll be out to check it out and I think I know what it is.
He explained the sacrificial anode thing to me and said that rod holds the impurities from your water inside the tank, rather than the impurities clinging to the tank walls.   It's supposed to make the tanks last longer.
His fix was to simply remove and dispose of the sacrificial anode and plug the hole where it inserts.   Said he has done this quite a bit, for the same issue.

So, I suppose my water heater may not last quite as long without it, but at least the water smells clean now.   I'm fine with that.

Curious with a dumb question but how do you determine whether or not you really need a water softener? Is it pretty much based on how bad the deposit build-up is on your faucets and fixtures over time?

[lthenderson]

I think the price tag when I replaced my water heater a few years ago was about $1200 installed. The new sealed combustion chamber tanks are quite a bit more expensive than the ones we used to get before they were mandated by law. Back then $350 was on the expensive side.

I have never replaced the sacrificial anode in a water heater. I have thought about it but they have always gotten so corroded that I was afraid I would permanently mess up the water heater before the threads broke loose. At least in our area, we have quite a bit of sediment in our water and by ten years or so, the water heater is full of sediment anyway reducing capacity and I'm assuming increasing it's propensity to rust out despite having a sacrificial anode. I used to flush them regularly but then the valves got so cheap that I had problems getting them sealed off again after flushing and then a plumber showed me the inside of a tank that was "regularly" flushed. There was a clear cone shaped area leading down to the spigot but still piles of debris everywhere else. After that I'm convinced that the only way to really flush a tank is to do it even more often, like monthly, and one would have to open and shut the incoming water valve a bunch of times during the process to stir up the sediment assuming that the water was hitting somewhere other than the cone area near the spigot. I just came to the point where I said that was enough and now I don't do anything anymore. I have never lived somewhere long enough to where I have had to replace a water heater that I replaced once before so I don't have any real data points about my method. But all three water heaters I replaced before, I'm fairly positive that the previous owners never did any sort of maintenance and they were all around 15 years old. So until someone can show me that flushing and replacing anodes will say double the life to 30 years, I probably not going to bother. At my age and since I just replaced mine a few years back, I probably will only have to replace it once more in my lifetime unless I perhaps move again.

I usually put in a water softener if toilet bowls quickly stain. They seem to stain first with hard water since the water sits there between uses and gets used fairly frequently. In my current house, the toilet bowl has yet to discolor so I never did put in a water softener. All my previous houses I had too but they were on different water supplies than I am now.

[jeromedawg]

Got the new water heater in. I'm impressed by the business that did it, starting from their response time to no-nonsense quoting and efficiency getting a tech to replace it "on his way" between appointments. Basically, I got a response from the owner at 8:19am and had the new water heater installed and paid for just before 1pm - probably the most efficient on-call home repair/service I've had done to date lol. Anyway, no bait and switch either - the $1295 quote is what they charged, so I'm pretty happy with it. He had to weld together a new copper pipe fitting with a MAPP torch.... aside from dragging a couple water heaters around, definitely not something I would have been able to do. Anyway, I'm relieved and glad it worked out. BTW: he put the pro grade Rheem tank in.

[Mighty Eyebrows]

His fix was to simply remove and dispose of the sacrificial anode and plug the hole where it inserts.   Said he has done this quite a bit, for the same issue.

You don't want to remove the anode completely. Your tank will probably rust out quickly.

https://www.watertechonline.com/home/article/15535688/replacing-anodes-getting-rid-of-odor

Either an aluminum/zinc anode or a powered anode are the recommended solution for the smell.

[zolotiyeruki]

I'm late to this party, but wanted to add a thought or two:
I replaced the anode and TPR valve on our water heater two years ago, when it was 12 years old.  The old anode was completely gone.  It wasn't that awful of a job.  Yes, cracking the threads loose was difficult, but it wasn't a huge deal.  It cost me something like $25 for the anode and $15 for a larger monkey wrench to get enough leverage.

The difference between a 6-year water heater and the 9- and 12-year versions is A) the size of the anode and/or B) simply the length of the warranty.

Some enterprising plumber needs to start offering a "water heater flushing service" where they stick a spray nozzle down inside the water heater to knock all the sediment off the walls.  Between that and a new anode, you'd extend your water heater's life for a LONG time.

[jeromedawg]

I'm late to this party, but wanted to add a thought or two:
I replaced the anode and TPR valve on our water heater two years ago, when it was 12 years old.  The old anode was completely gone.  It wasn't that awful of a job.  Yes, cracking the threads loose was difficult, but it wasn't a huge deal.  It cost me something like $25 for the anode and $15 for a larger monkey wrench to get enough leverage.

The difference between a 6-year water heater and the 9- and 12-year versions is A) the size of the anode and/or B) simply the length of the warranty.

Some enterprising plumber needs to start offering a "water heater flushing service" where they stick a spray nozzle down inside the water heater to knock all the sediment off the walls.  Between that and a new anode, you'd extend your water heater's life for a LONG time.

So it's possible to spray the inside of the water heater walls? I thought these things were mostly sealed - is that the sort of thing you can DIY? I know draining/flushing tanks is a pretty standard thing but never heard of getting a spray nozzle inside to 'pressure' clean the walls off.

[nereo]

I'm late to this party, but wanted to add a thought or two:
I replaced the anode and TPR valve on our water heater two years ago, when it was 12 years old.  The old anode was completely gone.  It wasn't that awful of a job.  Yes, cracking the threads loose was difficult, but it wasn't a huge deal.  It cost me something like $25 for the anode and $15 for a larger monkey wrench to get enough leverage.

The difference between a 6-year water heater and the 9- and 12-year versions is A) the size of the anode and/or B) simply the length of the warranty.

Some enterprising plumber needs to start offering a "water heater flushing service" where they stick a spray nozzle down inside the water heater to knock all the sediment off the walls.  Between that and a new anode, you'd extend your water heater's life for a LONG time.

So it's possible to spray the inside of the water heater walls? I thought these things were mostly sealed - is that the sort of thing you can DIY? I know draining/flushing tanks is a pretty standard thing but never heard of getting a spray nozzle inside to 'pressure' clean the walls off.

When you take off the anode (or remove one of the two heating elements) you are left with a 1" threaded port ("hole") large enough to stick a pressure-washing nozzle into.  I've never thought about power-washing the inside of my water heater but having replaced the heating elements can see how easy this would be.

Routine (e.g. yearly) draining of the sediment which accumulates at the bottom of the tank will also greatly extend the lifespan, as will regularly replacing the anode (every 3-5 years is recommended... which reminds me I should replace mine soon).

[jeromedawg]

I'm late to this party, but wanted to add a thought or two:
I replaced the anode and TPR valve on our water heater two years ago, when it was 12 years old.  The old anode was completely gone.  It wasn't that awful of a job.  Yes, cracking the threads loose was difficult, but it wasn't a huge deal.  It cost me something like $25 for the anode and $15 for a larger monkey wrench to get enough leverage.

The difference between a 6-year water heater and the 9- and 12-year versions is A) the size of the anode and/or B) simply the length of the warranty.

Some enterprising plumber needs to start offering a "water heater flushing service" where they stick a spray nozzle down inside the water heater to knock all the sediment off the walls.  Between that and a new anode, you'd extend your water heater's life for a LONG time.

So it's possible to spray the inside of the water heater walls? I thought these things were mostly sealed - is that the sort of thing you can DIY? I know draining/flushing tanks is a pretty standard thing but never heard of getting a spray nozzle inside to 'pressure' clean the walls off.

When you take off the anode (or remove one of the two heating elements) you are left with a 1" threaded port ("hole") large enough to stick a pressure-washing nozzle into.  I've never thought about power-washing the inside of my water heater but having replaced the heating elements can see how easy this would be.

Routine (e.g. yearly) draining of the sediment which accumulates at the bottom of the tank will also greatly extend the lifespan, as will regularly replacing the anode (every 3-5 years is recommended... which reminds me I should replace mine soon).

Interesting... in terms of draining/flushing the tank on an annual basis, how long would you say the lifespan increases? This last one was in there for around 14 years or so.

[zolotiyeruki]

Interesting... in terms of draining/flushing the tank on an annual basis, how long would you say the lifespan increases? This last one was in there for around 14 years or so.

I can't quantify it, but can tell you this: water heaters are a steel tank coated in some sort of enamel or other coating to prevent rusting.  Sediment and corrosion and other stuff sitting in the bottom of the tank will shorten the life of that coating.  How quickly that happens depends on what's in your water to begin with, and how often you flush the tank.

Nereo's suggestion of a pressure washer is a great one.  I might just have to borrow that one.

[nereo]

Interesting... in terms of draining/flushing the tank on an annual basis, how long would you say the lifespan increases? This last one was in there for around 14 years or so.

I can't quantify it, but can tell you this: water heaters are a steel tank coated in some sort of enamel or other coating to prevent rusting.  Sediment and corrosion and other stuff sitting in the bottom of the tank will shorten the life of that coating.  How quickly that happens depends on what's in your water to begin with, and how often you flush the tank.

Nereo's suggestion of a pressure washer is a great one.  I might just have to borrow that one.

wait... you're giving me credit for basically slightly tweaking your idea expressed upthread?  Um... thanks!

[zolotiyeruki]

Interesting... in terms of draining/flushing the tank on an annual basis, how long would you say the lifespan increases? This last one was in there for around 14 years or so.

I can't quantify it, but can tell you this: water heaters are a steel tank coated in some sort of enamel or other coating to prevent rusting.  Sediment and corrosion and other stuff sitting in the bottom of the tank will shorten the life of that coating.  How quickly that happens depends on what's in your water to begin with, and how often you flush the tank.

Nereo's suggestion of a pressure washer is a great one.  I might just have to borrow that one.

wait... you're giving me credit for basically slightly tweaking your idea expressed upthread?  Um... thanks!

My idea, but I hadn't figured out the right tool for the job.

[NaN]

When we bought our house it came with a gas powered tankless water heater. I am not sure what the exact prices are compared to normal tank heater but I know it is a bit more. I am not saying it has ROI potential - I won't even go down that road here. We would never have bought it for ourselves but because the house essentially came with we have been able to try it out.

I will say though that I really love it. Hopefully it lasts 20 more years. Ours has a built in recirculation line which is designed to feed hot water right below fixtures in two bathrooms, backtracks in the house to the kitchen sink, and then back to the water heater (an easy access crawl space makes this possible). Hot water is near instant in the bathrooms (no more starting the shower and waiting for a minute for it to heat up). The kitchen is fairly similar, too. Washing a single dish with warm water is quick. For being in an arid climate saving water feels pretty good. That is something I am willing to pay for.

Also, maintenance on it is an easy DIY job. There are some good videos online, but essentially each one has valves that allow you to bypass and connect up a bucket of vinegar water to flush the system with a low power sump pump. There are some other filters for the cold water and air intake that can be easily cleaned. I just did this about three months ago, took very little time. I just bring this up because of the comments about being able to clean a tank water heater.

[jeaneallenn]

Anyone have recommendations on a reliable 50 gallon natural gas tank heater?

Actually, I didn't know about this either until landed on a website promoting them on the internet. I do not remember the url right now, I will leave it here i remember.

[foghorn]

I just replaced the water heater in my home.  The dead one lasted 5 years and 10 months.  So, the replacement was under warranty (6 year warranty) - but I will still have the pleasure of paying the labor fees for the install on the new one.  Waiting for that bill.

In my area water heaters only last about 6 years.  My home is 18 years old and the new water heater is #4 for this house.  When #3 was installed I did a 2x per year draining and flushing.  It ended up being a complete waste of time.  I asked my plumber what is the deal with the water here?  He said it is what it is - and I might as well get used to replacing a water heater about every 6 years.  All of my neighbors face the same issue.  It is not uncommon to see plumbers in the neighborhood and water heaters being swapped out. 

I am curious if tankless water heaters last any longer?  I would consider it if they lasted a lot longer. 

[uniwelder]

I just replaced the water heater in my home.  The dead one lasted 5 years and 10 months.  So, the replacement was under warranty (6 year warranty) - but I will still have the pleasure of paying the labor fees for the install on the new one.  Waiting for that bill.

In my area water heaters only last about 6 years.  My home is 18 years old and the new water heater is #4 for this house.  When #3 was installed I did a 2x per year draining and flushing.  It ended up being a complete waste of time.  I asked my plumber what is the deal with the water here?  He said it is what it is - and I might as well get used to replacing a water heater about every 6 years.  All of my neighbors face the same issue.  It is not uncommon to see plumbers in the neighborhood and water heaters being swapped out. 

I am curious if tankless water heaters last any longer?  I would consider it if they lasted a lot longer. 

Its been mentioned in a few of the previous posts here--- check and replace the anode rod.  That's what protects your tank from rusting.  If your water heater only lasts 6 years, then check yours every year or two.  The rod costs about $30 from a plumbing supply store and you'll need a 1 1/16" socket to access it.  They're located at the top of the tank and are about 30 inches long or so.

[foghorn]

I just replaced the water heater in my home.  The dead one lasted 5 years and 10 months.  So, the replacement was under warranty (6 year warranty) - but I will still have the pleasure of paying the labor fees for the install on the new one.  Waiting for that bill.

In my area water heaters only last about 6 years.  My home is 18 years old and the new water heater is #4 for this house.  When #3 was installed I did a 2x per year draining and flushing.  It ended up being a complete waste of time.  I asked my plumber what is the deal with the water here?  He said it is what it is - and I might as well get used to replacing a water heater about every 6 years.  All of my neighbors face the same issue.  It is not uncommon to see plumbers in the neighborhood and water heaters being swapped out. 

I am curious if tankless water heaters last any longer?  I would consider it if they lasted a lot longer. 

Its been mentioned in a few of the previous posts here--- check and replace the anode rod.  That's what protects your tank from rusting.  If your water heater only lasts 6 years, then check yours every year or two.  The rod costs about $30 from a plumbing supply store and you'll need a 1 1/16" socket to access it.  They're located at the top of the tank and are about 30 inches long or so.

Thanks.  I have seriously considered doing exactly that.  However, the water supply line to the water heater (from the softener) runs horizontally right above (about 6 inches) the anode rod.  So, I doubt I could ever get it out (once loosened).  I know I can buy a segmented anode rod as a replacement - but getting the old one out would be a real bitch/impossible.

[lthenderson]

I am curious if tankless water heaters last any longer?  I would consider it if they lasted a lot longer.

In my opinion, the jury is still out on this question. Although tankless water heaters have been around since the early 1920's or so, they have only become popular (and practical) in the last 10 or 15  years. The last time I priced one, they cost three times the prices of a tank water heater. In my area, a tank water heater will last around 15 years so a tankless would have to last 45 years in order to pay for itself. Of course there is an energy savings I'm not taking into account but even if that reduced it in half to 22.5 years, I just don't see that as likely physically speaking and practically speaking, periodic remodels and changes in technology would probably mean they get replaced much sooner than that. I think some could justify them but the vast majority of us can't.

[nereo]

The energy savings can be significant - particularly if you are a low-demand or periodic (I.e morning/evening) user.

Most analyses I’ve seen (incl EPA energy star) say around a 1/3 reduction in electricity cost for those users.

Then of course you get into electricity costs and longevity et
For our calculations, a tankless water heater saved us an estimated $0.34 per day. Which seems like nothing, but that’s $124 each year, which in turn put the payback period at just over five years (assuming a $999 purchase price for a tankless unit Vs $350 for a decent traditional electric)

Ironically the less you use the better the savings, as the energy savings is all in ‘leakage’ of keeping a bunch of water in a tank until needed.

[NaN]

I am curious if tankless water heaters last any longer?  I would consider it if they lasted a lot longer.

In my opinion, the jury is still out on this question. Although tankless water heaters have been around since the early 1920's or so, they have only become popular (and practical) in the last 10 or 15  years. The last time I priced one, they cost three times the prices of a tank water heater. In my area, a tank water heater will last around 15 years so a tankless would have to last 45 years in order to pay for itself. Of course there is an energy savings I'm not taking into account but even if that reduced it in half to 22.5 years, I just don't see that as likely physically speaking and practically speaking, periodic remodels and changes in technology would probably mean they get replaced much sooner than that. I think some could justify them but the vast majority of us can't.

I'll let you guys know how mine fares (only 3 years in). I hope I just never comment on it before 15 years. :) I have done the recommended flushing of the system with vinegar water once already and plan to stay up on it (unless a power surge take it out!). Regarding the price, absolutely, it is more expensive. I see the only pluses of a tankless heater are 1) in a house with a lot of showers, etc. 2) a love for instant hot water when a recirculation system is also used. Energy and water savings are a plus, particularly if you live in an area with water use concerns.

[sonofsven]

Tankless gives you more options in installation as well, since they're so small. They do need a good source of combustion air, however.
I have a basic gas tank water heater with a pilot light, not the most efficient, but when the power is out it sure is nice to have hot water.
My gas use is so low that the payoff for an increase in efficiency is basically longer than the expected lifespan of the appliance.

[Mighty Eyebrows]

The energy savings can be significant - particularly if you are a low-demand or periodic (I.e morning/evening) user.

Most analyses I’ve seen (incl EPA energy star) say around a 1/3 reduction in electricity cost for those users.

Tankless is best used with natural gas, and not just for cost. If you do electric, it will draw a very large current so you need to make sure your house electrical service can handle it.

[NaN]

I have a tankless hot water heater from Navien and love it. This past week I learned that Navien, and many others, also make combo tankless boiler/water heaters. Basically, one unit to feed radiant heat hot water and domestic hot water. This would be remarkably efficient for one utility closet to contain both whole house heating and domestic hot water. By adding radiant heating I could remove my furnace/forced air system, changing the furnace in the bedroom hallway to a linen closet and raising ceilings in the master closet with drop down ductwork. Because we don't have AC, and if we did want to add it we would use mini-splits anyway, this won't be a problem. What a remarkable product!

[thedigitalone]

I replaced a gas hot water tank that started leaking after 20 years this weekend with an on-demand tankless system. 

My local utility offers has a $250 bill credit for installing a high-efficiency replacement, and there is a $300 federal tax credit as well. The tankless system was on sale for $799 will end up only costing us $249, you should check and see if your local utility offers any rebates.

https://www.pse.com/rebates/water-heating/natural-gas-tankless-water-heater-rebate
https://www.energystar.gov/about/federal_tax_credits/non_business_energy_property_tax_credits

[bacchi]

I just installed a hybrid in the attached garage. The app has a day of the week/hourly schedule, almost encouraging the user to alter the temperature.

From my quick reading, legionella slowly dies at 50c/120f+. As long as it's over 120f for more than a few hours, that's not a problem.

Is there an optimum strategy here? Let it drop to 110f/43c at night and bring it back up to 125f/51c in the morning, the coldest part of the day? Bring it up to 130f at 4-5pm, the warmest part of the day, and then let it drop from there to 120f?

Or use the schedule only when we're out for most of the day and don't need hot water for 24+ hours?

[nereo]

I just installed a hybrid in the attached garage. The app has a day of the week/hourly schedule, almost encouraging the user to alter the temperature.

From my quick reading, legionella slowly dies at 50c/120f+. As long as it's over 120f for more than a few hours, that's not a problem.

Is there an optimum strategy here? Let it drop to 110f/43c at night and bring it back up to 125f/51c in the morning, the coldest part of the day? Bring it up to 130f at 4-5pm, the warmest part of the day, and then let it drop from there to 120f?

Or use the schedule only when we're out for most of the day and don't need hot water for 24+ hours?

Just my musings, so take them with a grain of salt...

You mentioned legionella in your post about optimal heating strategies. To my understanding, it’s a concern for water that will sit in less-than-lethal temperatures for several days, or more likely even weeks. I don’t think it’s much of a concern on a daily fluctuation. If that were the case there would be PSAs about water use anytime the power went out, or anytime went away in vacation and turned the heater off. So I’d ignore it for daily temperature changes

S for the best (most energy efficient) practices - that will depend on your demand. If you a “guy/gal who showers in the morning “, set it to peak right before shower time and then go back down. Time your hot water needs with peak demand, and let it go much lower when you anticipate no or minimal usage C (ie when you are normally out and about, or sleep)

[uniwelder]

I just installed a hybrid in the attached garage. The app has a day of the week/hourly schedule, almost encouraging the user to alter the temperature.

From my quick reading, legionella slowly dies at 50c/120f+. As long as it's over 120f for more than a few hours, that's not a problem.

Is there an optimum strategy here? Let it drop to 110f/43c at night and bring it back up to 125f/51c in the morning, the coldest part of the day? Bring it up to 130f at 4-5pm, the warmest part of the day, and then let it drop from there to 120f?

Or use the schedule only when we're out for most of the day and don't need hot water for 24+ hours?

I've been interested in hybrid water heaters and tried looking up some info about your question.  Eventually, I might end up using one for hydronic floor heating.  Here's a useful link----https://energy350.com/wp-content/uploads/2018/11/FortisBC-Heat-Pump-Water-Heater-Presentation-Slides-7.18.2018.pdf

They tried out two different types.  The Rheem model is likely similar to what you have.  One of the tested units (site 5) was placed in a garage, with the exhaust air ducted outside.  If you go down a few pages, it shows COP vs temperature.  The unit operates at 1.0 at 32 degrees, which is the same as a regular water heater.  It dropped to less than 1 as the temperature fell below that.  I'm not sure how that is--- logically I would think it would just go to normal resistance heat if the heat pump couldn't operate efficiently.  However, as temperatures went above freezing, the COP went to 1.25 at around 40 degrees and COP=1.5 around 50 degrees, and Cop=2 around 60 degrees.

To make the most of your heat pump unit, you probably want to make your heater run when its warmest outside, though I don't know your climate situation.  Ducting the exhaust outside would be very smart too, and if it has an anode rod, make sure to change it out regularly.  Otherwise, I don't think you'll get your money back on the investment.

[bacchi]

I just installed a hybrid in the attached garage. The app has a day of the week/hourly schedule, almost encouraging the user to alter the temperature.

From my quick reading, legionella slowly dies at 50c/120f+. As long as it's over 120f for more than a few hours, that's not a problem.

Is there an optimum strategy here? Let it drop to 110f/43c at night and bring it back up to 125f/51c in the morning, the coldest part of the day? Bring it up to 130f at 4-5pm, the warmest part of the day, and then let it drop from there to 120f?

Or use the schedule only when we're out for most of the day and don't need hot water for 24+ hours?

I've been interested in hybrid water heaters and tried looking up some info about your question.  Eventually, I might end up using one for hydronic floor heating.  Here's a useful link----https://energy350.com/wp-content/uploads/2018/11/FortisBC-Heat-Pump-Water-Heater-Presentation-Slides-7.18.2018.pdf

They tried out two different types.  The Rheem model is likely similar to what you have.  One of the tested units (site 5) was placed in a garage, with the exhaust air ducted outside.  If you go down a few pages, it shows COP vs temperature.  The unit operates at 1.0 at 32 degrees, which is the same as a regular water heater.  It dropped to less than 1 as the temperature fell below that.  I'm not sure how that is--- logically I would think it would just go to normal resistance heat if the heat pump couldn't operate efficiently.  However, as temperatures went above freezing, the COP went to 1.25 at around 40 degrees and COP=1.5 around 50 degrees, and Cop=2 around 60 degrees.

To make the most of your heat pump unit, you probably want to make your heater run when its warmest outside, though I don't know your climate situation.  Ducting the exhaust outside would be very smart too, and if it has an anode rod, make sure to change it out regularly.  Otherwise, I don't think you'll get your money back on the investment.

Thanks. That's a helpful link.

I may exhaust the cooled air for the winter and let it vent into the garage for the summer.

The anode rod is not really replaceable in the Rheem. It's something to consider in a few years (using a hack saw) but, then again, the previous water heater lasted 25 years without replacing the rod or even draining it much.

Strategy: Time showers and dishes for the late afternoon/evening when it can heat with the afternoon temps and then let it drop.

[Mighty Eyebrows]

I've been interested in hybrid water heaters and tried looking up some info about your question.  Eventually, I might end up using one for hydronic floor heating.  Here's a useful link----

https://energy350.com/wp-content/uploads/2018/11/FortisBC-Heat-Pump-Water-Heater-Presentation-Slides-7.18.2018.pdf

Thanks for the link (I made it clicky). That is from our part of the world!

Moral of the story: Sanden (split CO2 system) is expensive but designed more for hydonic heating. It looks like basic Rheem models are good for domestic hot water if you don't duct them to the outside.

I am surprised the COPs weren't higher. The new minisplit heating systems out there handle cold weather pretty well now.

[Glenstache]

I replaced my aging electric water heater with a heat pump / hybrid water heater last summer. The rebates from my local utility made it pretty close to cost neutral relative to buying a regular resistance unit. It was a pretty easy project to do the install. An added benefit is that it is a very effective dehumidifier for my garage, which is nice in the damp PNW winters. I have not been able to review efficiency over a full year, but the last few months have shown reduced energy use compared to the prior year. I am not sure if there are other use patterns that would account for any of that, but if the trend holds, I'll be pleased.

[Wrenchturner]

Not a huge fan of tankless.  Too many components, too many failure modes.  They do work pretty well in my experience though. 
When the tankless water heater malfunctioned at my house, it took a third plumber to fix it.  And I pointed out to the landlord that it was never installed right(no condensation drain line) so I think he got that fixed for free.