Help troubleshooting a high electric bill

[La Bibliotecaria Feroz]

At great cost, we fully electrified our house. We expect that we might have higher energy bills in the winter- but it's been summer. Last year we installed a heat pump water heater and this year we installed a heat pump for heating and cooling, which should be cheaper to run than the old AC.

But our usage is higher by a noticeable amount and has been all summer. So far the only thing we've found is that we didn't know the water heater had a filter that we need to clean. So, we cleaned it. I don't know how much difference that could be making, though. Oh, and it was set to Hybrid mode. I put it back into Efficiency mode most of the time and only turn it into Hybrid on days when I am planning to take a bath. It runs 24/7. (It is probably too small for our family. We were pretty happy wtih a 50 gallon gas tank, or maybe even 40?- which translates to the 65 gallon heat pump tank that we got, but we do have 5 people in the house.)

What else could we be looking at in the meantime? Has anyone else run into this problem?

ETA: We also had our attic re-insulated, so that's another reason I would expect lower costs.

[seattlecyclone]

I guess I wouldn't necessarily expect a new heat pump to be that much cheaper to operate than your old air conditioner, since air conditioners are heat pumps already. Maybe it's a bit more efficient, but that could be offset if you use it more often than the old AC or keep the temperature set to a lower level.

[SweatingInAR]

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It runs 24/7.
...

Do you mean to say that your heat pump water heater is continuously running its compressor (making a sound)? That is not good! You probably have a hot water leak somewhere, or you do not have a proper heat trap. I know that the Rheem HPWH require an external heat trap. This stops hot water from rising out of the tank, cooling, and falling back in. If nobody is drawing any hot water, are the pipes warm? Is your water heater "smart"? It may have some helpful usage statistics.

Do you have a recirculation pump for your water heater? That should be controlled by an on-demand button, a timer, or permanently removed. It definitely should not be on continuously.

Can you share approximately how many kwh higher the bills have been this year versus previous years? Then we can divide the number of kwh by hours in the month to better guess what is burning up the power. Some utilities even have detailed usage information in your online account. You could go on and see if the extra usage is "peaky" or merely a higher baseline.

[La Bibliotecaria Feroz]

I guess I wouldn't necessarily expect a new heat pump to be that much cheaper to operate than your old air conditioner, since air conditioners are heat pumps already. Maybe it's a bit more efficient, but that could be offset if you use it more often than the old AC or keep the temperature set to a lower level.

We use it exactly the same and had the attic professionally insulated.... I definitely wouldn't expect usage to go UP! By a lot! How much varies by month but it's consistently higher over the year before.

@SweatingInAR - Yes, the heat pump runs nonstop. We had a plumber out to look at it but he just said to clean the filter. The rest of your post I don't really understand off hand so I will have to do some more research.

The increase in usage ranges from like 100 to as high as 600 over the previous year.

[secondcor521]

Two suggestions:

1.  Borrow a Kill-a-Watt and go around and find out what uses how much electricity.

2.  Ask your electric company for help.  They might give you some ideas.  They might also come out and do an energy audit with you.

My electric provider shows me daily and hourly usage stats.  It would be hard, because energy usage can vary so much hour to hour and day to day.  But if you are able to look at those hourly and daily stats comparing months this year to last year, you might be able to deduce what time(s) the power usage increases to help give you a clue.

The several big electric users I know are:  A/C, clothes dryer, electric stove, and electric water heater.  Have your habits changed with any of those?  Did you have a hotter summer this year than last?  Are you washing and drying more clothes?  Cooking from home more?

FWIW, I went from about R19 to R60 in my attic a few years ago and noticed very little change in my electric bill.  The house did seem more comfortable, though, and there is a tax deduction for insulating, so I was still glad I did it.

[jrhampt]

We had a heat pump installed last year and it was running continuously too.  Turned out it had a leak.  I would contact your original installer, who should be able to do a better job of figuring out what’s wrong than the plumber.  In our case it took him a couple of visits to pinpoint the issue.  Very small part.

[La Bibliotecaria Feroz]

We had a heat pump installed last year and it was running continuously too.  Turned out it had a leak.  I would contact your original installer, who should be able to do a better job of figuring out what’s wrong than the plumber.  In our case it took him a couple of visits to pinpoint the issue.  Very small part.

Unfortunately the installer went out of business! Where was it leaking?

[curious_george]

For reference I have a family of six and a 50 gallon heat pump water heater. It is always set to heat pump only mode, and it certainly does not run 24/7. It runs maybe 4-6 hours a day or so, depending on usage. 

The compressor on your hybrid water heater should not be running 24/7. While having a dirty air filter can decrease the efficiently, this by itself likely cannot account for it running 24/7.

Where is it installed? This almost makes me wonder if it is installed in a small closet somewhere.... (Which would not be ok for these water heaters as they need a certain volume of air to pull thermal energy out of before they cool the whole space down around them to the point of making themselves inefficient to run).

ETA: The recovery time on my water heater running in heat pump only mode is 8 gallons per hour. If your water heater is similar and running 24/7, this implies you are using 192 gallons of hot water per day. Which seems to tell me there is a problem with your water heater.

[La Bibliotecaria Feroz]

@TreeLeaf - that's a really helpful data point. I think it used to not run so much, so it must be a new problem like a leak.

It's installed in a small laundry room and we don't close the door - so maybe not optimal but should be good enough. I'm actually planning to have it vented outdoors this fall as it drops the basement temperature like 5 degrees F and we and our toddler sleep down there!

[daverobev]

@TreeLeaf - that's a really helpful data point. I think it used to not run so much, so it must be a new problem like a leak.

It's installed in a small laundry room and we don't close the door - so maybe not optimal but should be good enough. I'm actually planning to have it vented outdoors this fall as it drops the basement temperature like 5 degrees F and we and our toddler sleep down there!

Do you have access to daily readings? Or hourly? Or can you see your meter?

We just had a hybrid tank put in and it draws like 2kWh a day. I think beforehand we used about 5kWh of gas on hot water. I've got ours programmed so it is off between 6am and 1pm because that time is least likely to have sun and our off peak rate stops at 6am. So at 1pm it comes on, sometimes drawing 500W, sometimes 2kW, and after an hour or two it shuts off again, when the tank's 'full' (I've got it set to the minimum because we don't use that much water...).

If you can see your meter or get daily readings, just try measuring two days, one with it on and one with it off (should be enough hot water to last a day without too much discomfort?).

[jrhampt]

We had a heat pump installed last year and it was running continuously too.  Turned out it had a leak.  I would contact your original installer, who should be able to do a better job of figuring out what’s wrong than the plumber.  In our case it took him a couple of visits to pinpoint the issue.  Very small part.

Unfortunately the installer went out of business! Where was it leaking?

That is very unfortunate. Is there another heat pump installer/servicing company that you can get to take a look at it?  It was leaking coolant from somewhere because of a very tiny part that didn't have the gasket fully intact but idk where exactly.  He had to vacuum test it.

[curious_george]

@TreeLeaf - that's a really helpful data point. I think it used to not run so much, so it must be a new problem like a leak.

It's installed in a small laundry room and we don't close the door - so maybe not optimal but should be good enough. I'm actually planning to have it vented outdoors this fall as it drops the basement temperature like 5 degrees F and we and our toddler sleep down there!

Yeah - if it is only a 5 degree drop and the door is open then it sounds like a refrigerant leak is the next most likely issue.

I don't know your rates or power consumption of your water heater, but I know in my case if my water heater were running 24/7 that would add around 50-60 dollars to my bill.

If I were in your shoes I would probably switch it over to use the internal heating elements only / electrical resistance mode until I could get it sorted out.

[SweatingInAR]

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If I were in your shoes I would probably switch it over to use the internal heating elements only / electrical resistance mode until I could get it sorted out.

This is also a great way to test, if you also have a way to track your daily electric usage. Switch it to heating elements only and see if your daily electric usage goes down. If it does, you know the compressor itself is to blame. If usage goes up, you may have a water leak, installation issue, or some other issue entirely.

What is the model of water heater?
Can you post a picture of the installation?
After no hot water is used for an hour, feel the pipes going into and out of the WH. Are they hot?

[eyesonthehorizon]

Posting in part to follow because this is really remarkable about the water heater, & I hope you’ll share any updates. Aside from that, though: I hope you find something clearly at fault that is easy to fix very soon, whatever it proves to be!

[Paper Chaser]

I'm not clear on whether your usage is up (consuming more kwh of electricity), your bills are higher (more money owed each month), or some combination of both.

Electrical rates have been increasing pretty much everywhere. So it's at least possible that your usage hasn't changed much, but the bills could be higher.

[La Bibliotecaria Feroz]

I'm not clear on whether your usage is up (consuming more kwh of electricity), your bills are higher (more money owed each month), or some combination of both.

Electrical rates have been increasing pretty much everywhere. So it's at least possible that your usage hasn't changed much, but the bills could be higher.

No, I looked at the usage in kwH and it is much higher year over year over a period of months.

...
If I were in your shoes I would probably switch it over to use the internal heating elements only / electrical resistance mode until I could get it sorted out.

This is also a great way to test, if you also have a way to track your daily electric usage. Switch it to heating elements only and see if your daily electric usage goes down. If it does, you know the compressor itself is to blame. If usage goes up, you may have a water leak, installation issue, or some other issue entirely.

What is the model of water heater?
Can you post a picture of the installation?
After no hot water is used for an hour, feel the pipes going into and out of the WH. Are they hot?

I haven't figured out how to check the daily usage but yes, the pipes still feel hot after an hour or two of no hot water usage I think. Does that mean I could have an invisible hot water leak somewhere?

In the meantime I did turn it into electrical mode because I was worried about the compressor running so hard round the clock. It does not constantly run in resistance mode.

I don't have a picture but it's an AO Smith and when I had the HVAC heat pump installed, they also checked the water heater installation (which was done by a different company and the new company had absorbed their business) and they said it looked good.

My hsuband was supposed to call someone yesterday but he forgot so I will call a manufacturer recommended service provider on Monday.

[SweatingInAR]

Thanks for the update!

Unfortunately, some utilities don't offer useful electricity tracking. The one I had in AZ was great, I could see hourly data. My electric company where I live now in AR doesn't have a useful website, and only gives me a monthly total on my bill.

If just the hot water outlet feels hot at least a foot away, I would guess that you have a leak somewhere. If both the cold inlet and hot outlet are hot (again, at least a foot away), it could be a faulty heat trap or some other way that water is flowing. A picture of the installation would help us guess what is going on.

Do you have a recirculation pump? They are devices that constantly (or on-demand) circulate hot water through the house so you don't have to wait for hot water at your kitchen or bathrooms. I have never actually encountered one... so they are probably only common in large luxury homes.

What is the exact model number of your water heater? AO Smith has a bunch of different models. It will be a combination of letters and numbers, like "HP10-50H45DV" or "FPTU-50". This will be on an information sticker on the water heater with the serial number and other info. It may also be on the Yellow Energyguide sticker, like this one: https://pdf.lowes.com/productdocuments/279fffc0-2bb9-421f-9d09-324129f9d4c0/62403408.pdf

See the small text on the right side near the top that says: "Model(s) HP1050H45DV 130"?

Unless the HVAC company went line-by-line through the installation manual for the water heater, they could have missed something.


Can you tell how frequently the water heater is cycling with its heat pump deactivated? My cheap builder-grade electric water heater only cycles once every 12 hours if nobody draws any hot water. I did a ton of research into replacing it with a heat pump model, but decided against it because my family's usage is too low.

[Cranky]

Can you tell how frequently the water heater is cycling with its heat pump deactivated? My cheap builder-grade electric water heater only cycles ones every 12 hours if nobody draws any hot water. I did a ton of research into replacing it with a heat pump model, but decided against it because my family's usage is too low.

In the summer, the only thing in my house that uses natural gas is the water heater. The gas portion of my bill is about $15 of which actual gas usage is under $4. I think we use plenty of hot water - showers and dishes for three people - but it must not take a lot of energy to heat that up.

[La Bibliotecaria Feroz]

@SweatingInAR - Ha, no, I do not have a fancy circulating device. It's model HPTU-66N 130.

I finally got someone knowledgeable on the phone. First of all, she said that my usual plumber does have techs trained in my water heater, so presumably they sent a guy who knows the equipment. She also said that running round the clock is NORMAL for a unit that is not vented to the outdoors- so much so that many people find it bothersome and ask to have their fancy heat pump units locked into electric mode- and does not necessarily indicate a problem.

(But... is this true? My water heater is currently running. Let's assume that I ran it mostly empty last night at 10 pm, although when my bath finished there was still hot water. At 8 gallons per hour, it would take just over 8 hours to heat the tank back up. We ran the dishwasher at 1 am and again at 1pm, and my husband took a shower this morning. That's like 30 gallons total usage, maybe 40 if the 12yo took a shower, which should take only 5 hours to recover. So 13 hours of running time, tops, but it has been running nonstop all day. WTF?)

So I don't know if it's worth having someone come back out, or what other causes I could be pursuing. I will try to find my electric meter I guess. And maybe go ahead and pursue the outdoor venting.

[Tigerpine]

It's installed in a small laundry room and we don't close the door - so maybe not optimal but should be good enough. I'm actually planning to have it vented outdoors this fall as it drops the basement temperature like 5 degrees F and we and our toddler sleep down there!

You don't have the diagnostic code ECF showing on the display by chance, do you?  If so, you may want to check the size of the room the heater has been installed.  According to the chart in the manual (p20--see link below), if you have that diagnostic code, one of the corrective actions is to check the confined space requirements, quoted below from page 9.

Link to manual.
https://assets.aosmith.com/damroot/Original/10004/100323093.pdf

The location has adequate space (clearances) for period- ic servicing. For optimal water
heater efficiency, the unit must have unrestricted airflow and requires a minimum installation space of 700 ft3/19.8 m3. As an example, a room that has an 8 foot tall ceiling and is 10 ft/3 m long by 8-3⁄4 ft/2.6 m wide would contain 700 ft3/19.8 m3.

Also, just for reference, here's a link to the Service Handbook.
https://assets.aosmith.com/damroot/Original/10004/100268628.pdf

[La Bibliotecaria Feroz]

@Tigerpine - no, no error codes.

I found the electric meter but it has a digital display that rotates through several screens, none of which I understand, so I would have to, like, take a video or something to tell how fast it is spinning.

After several tedious phone calls I found out that our plumber actually IS certified on those water heaters but my husband wants to get a 2nd opinion so he's going to call someone today. If they don't find anything either, we might just go ahead and have the venting to the outside done and see if it works better that way.

[SweatingInAR]

...
She also said that running round the clock is NORMAL for a unit that is not vented to the outdoors- so much so that many people find it bothersome and ask to have their fancy heat pump units locked into electric mode- and does not necessarily indicate a problem.
...
And maybe go ahead and pursue the outdoor venting.

I would only mess with venting if the room in which it is situated is getting too cold. It looks like 45F is the lower limit on the compressor. Even then, I would prefer to vent it to an area that will always have a temperature between 45F and 120F so the heat pump can run.

You could check for a hot water leak in your house by shutting off the hot water valve coming from your water heater. If the compressor cycles off, there's a good chance you have a leak.

After all of this, continuous running might be OK! Here is a similar discussion on reddit:
https://www.reddit.com/r/heatpumps/comments/11r46v3/is_a_heat_pump_water_heater_always_running/

[La Bibliotecaria Feroz]

...
She also said that running round the clock is NORMAL for a unit that is not vented to the outdoors- so much so that many people find it bothersome and ask to have their fancy heat pump units locked into electric mode- and does not necessarily indicate a problem.
...
And maybe go ahead and pursue the outdoor venting.

I would only mess with venting if the room in which it is situated is getting too cold. It looks like 45F is the lower limit on the compressor. Even then, I would prefer to vent it to an area that will always have a temperature between 45F and 120F so the heat pump can run.

You could check for a hot water leak in your house by shutting off the hot water valve coming from your water heater. If the compressor cycles off, there's a good chance you have a leak.

After all of this, continuous running might be OK! Here is a similar discussion on reddit:
https://www.reddit.com/r/heatpumps/comments/11r46v3/is_a_heat_pump_water_heater_always_running/

If I open all the upstairs vents and set the thermostat to my preferred temperature of 69 degrees, the temperature in the basement- where the master suite is located- drops as low as 52 degrees. I once brushed my teeth in a beanie. So venting outside is intended to prevent it from making the basement frigid. Water heater dropped the temp down there about 5 degrees!

[nedwin]

I live in the same region as you, so have followed your post about the new heat pump with interest.  I think increased electricity use this summer over last may make sense, at least some of it.  First, you replaced a gas water heater with an electric water heater, so of course you will use more electricity than before the new water heater.  Are you comparing summer months with the new water heater, or without?

Second, it has been much warmer in the Denver metro (that's where you're at, right?) this summer over last.  My Xcel statements show the average temperature over the billing period and this summer has been as much as seven degrees warmer than last year.  This leads directly to more electricity use, especially if you set your cooling to 69 degrees.

Another factor may be the new heat pump.  It might be that the new heat pump is sized or built to be most efficient during heating months, which could lead to it using more electricity during cooling months than a normal, appropriately sized AC would.  I once replaced a boiler and added a zone to it to replace the gas water heater, so the boiler heated domestic hot water in addition to the living space.  The boiler was sized to heat the house, so it burned more gas than a gas water heater when it was only used for hot water.  Over the course of the year the new boiler reduced gas use by over 40%, but it did slightly increase gas use in the summer.

You should still explore whether the water heater is operating correctly, including that it was installed in a room with sufficient volume for efficient operation or that venting may be necessary.  You could consider replacing shower heads with low flow heads (1.75 gpm or lower rather than 2.5 gpm).  I did this to my home to cut down on water use but found that they saved way more on the gas bill than they did on the water bill.

If you have Xcel as your electricity provider you have access to nearly real time use information.  You can access this through your online account and selecting My Energy from the home page.  It might also be available through the Xcel app.  Also, Xcel used to offer home energy audits for free, they might still.  The audit will do a blower door test to see how much air leakage your home has and provide information about cost effective steps you can take to cut electricity use.  Now that you have these new systems it would be worthwhile to do the energy audit to learn what other steps you can take to reduce electricity use.

[La Bibliotecaria Feroz]

@nedwin - We already did the energy audit with the blower test! And then we had the attic professionally insulated, that was really the only big dollar item that was practical to change and I don't recall that they found any sort of smoking guns.

The manufacturer rep that the plumber talked to does NOT think that venting to the outside will help with the run time, although it would probably make the basement warmer- but we could accomplish the same thing by changing over to electric resistance mode on very cold days. (And the plumber confirmed that he's heard the same thing from other heat pump water heater makers.) Everyone seems to agree that the room is large enough as long as we don't close the door, which we do not. Anyway, 2 different plumbers, one of whom made a long call to the manufacturer, agree that there is no leak and no other problem and that it would show an error code if there was a problem.

The My Energy page on my Xcel account is nonfunctional for reasons that are not clear to me. It just says that they don't have enough information. But it's good to know that it has been consistently hotter- that could certainly be a factor. To be clear we do not COOL to 69- that is the winter thermostat setting that I prefer, but we generally have to turn it up to 72 to keep the basement even remotely usable. We HEAT to 69-72 and we COOL to 77.

The water heater was installed early last summer, maybe early June? So for July-September we should have accurate data, and then the HVAC heat pump was installed in April of this year and our costs skyrocketed as soon as cooling season started.

The whole process has been unsatisfactory and at this point I can't recommend that anyone follow in my footsteps.

[nedwin]

Has Xcel installed a time-of-use meter on your home?  They installed one on our house a couple months ago and My Energy works for me.  They hung info about it on our door before and after the install.  I thought they did Denver metro first before other areas (I'm well north).  It might be worth a call to Xcel if the new meter has been installed.

If the water heater is correct, your next step would be to investigate the heat pump.  Does it have resistance back up heat?  Maybe those are on for some reason.

[zygote]

The water heater was installed early last summer, maybe early June? So for July-September we should have accurate data, and then the HVAC heat pump was installed in April of this year and our costs skyrocketed as soon as cooling season started.

Hmmm, this makes me think the issue is the HVAC and not the water heater, if you had the water heater last summer and the bills didn't skyrocket until this year. I don't know enough about HVAC systems or heat pumps to know how to remedy that, though.

The timing could also be a coincidence, and you have another appliance on the fritz. It might be worth buying or borrowing a kill-a-watt to test out the energy usage of your other big ticket electricity-hoggers. The main one that comes to mind from personal experience is the fridge. Ours is old with a bad seal, and it definitely has to work a lot harder to stay at a food safe temperature in the summer. I have to turn the temperature dial down several notches each May - September. Any chance something's up with your fridge?

[ak907]

You could try adding and electricity monitor like Sense or Emporia Vue to your panel. I have a Sense and I find it helpful and entertaining (I did find a hardwired (no switch) light activated by a light sensor outside my house I did not know the previous home owner had installed which was using ~10% of my electricity per month (180w bulb on all night) with it (didn't know it was using sooo much electric)). It does take a few months to identify devices with its 'AI', some people don't find it good enough at it. Emporia does things by circuit, but you need to know what is on those circuits (and that many ct clamps take up considerable space). They are pretty cheap IMO if you are willing to install yourself (super easy in my opinion, hint take a 240v breaker and use a Wago lever nut to split it between the energy monitor and the device the breaker is feeding).

[La Bibliotecaria Feroz]

Has Xcel installed a time-of-use meter on your home?  They installed one on our house a couple months ago and My Energy works for me.  They hung info about it on our door before and after the install.  I thought they did Denver metro first before other areas (I'm well north).  It might be worth a call to Xcel if the new meter has been installed.

If the water heater is correct, your next step would be to investigate the heat pump.  Does it have resistance back up heat?  Maybe those are on for some reason.

Yes, I do have the time of use. It took 45 minutes on the phone the other day just to get anyone to pick up and they don't have an email, so calling might not be like my #1 priority but I will look into it!

We did not have resistance backup heat installed at all so we can rule out that possibility!

@zygote - that's an interesting suggestion! I will look into it.

@ak907- I am Hard Pass on electric work! But I will look into other ways to gather the information.

[big_owl]

I'm on my second AO Smith heat pump water heater.  The first one lasted two years and developed a refrigerant leak.  It would run all the time and eventually threw up an error code.  Call the AO smith tech support.  They waked me through taking intake and discharge air temps while the unit was running to determine that was the issue.  I got a new one for free and it's behaving much better.  It was a hassle because I had to take it back to the distributer (lowes) myself for the in-person swap (I installed it myself).  Hybrid water heaters are big and heavy!