Pipes started banging when they never have before - Mystery Solved

[Sibley]

I am not a plumber. And I know that pipes occasionally bang, but my pipes have never done anything like this before. The water isn't running anywhere in the house, and I'll hear pipes banging upstairs. This started just a few days ago.

The bathtub drain is slow I know, but other than that it seems all drains are in good order. I checked the cleanout and the main sewer line out seems to be running fine. It gets cleaned out annually (thanks oak tree). No changes to the plumbing upstairs in the past year or more. The utility room drain got reworked in December, but that's on the other side of the house and that drain is seperate, hooking into the sewer line closer to the street than where the house hooks in.

I also hear some gurgling noises from the downstairs bathroom sink and toilet after either are used.

What do I check? It's annoying.

[Glenstache]

Make sure your vents are clear. If you don't have clear vents for the drain lines (usually a pipe that pokes above roofline), then it will create suction and draw water out of the p-trap of adjacent fixtures. If the gurgling is air coming out of the fixture, then there is a blockage causing water to back up in the lines displacing air through the p-trap.

If the banging is the supply side, then it could also be use elsewhere at high velocity. A number of years ago a neighbors main broke, which then caused the pipes in my house to start vibrating and banging because of the pressure fluctuations in the lines at the main.

In short, knowing what pipes are banging where is useful to know.

[Sibley]

It's the damn humidifier. I don't remember it being that loud last year. Hanging out upstairs is illuminating at times.

[BudgetSlasher]

It's the damn humidifier. I don't remember it being that loud last year. Hanging out upstairs is illuminating at times.

Sounds like you have a "water hammer" issue. Basically the solenoid valve in the humidifier closes very quickly and all the energy of the flowing water is transferred to the pipe. 

they make water hammer arrestors, basically an air bladder, that compress and absorb the energy preventing it from being transferred to the piping/tubing. I've heard people also partially close the valve on that kind of appliance to slow the flow of water and reduce the energy transferred.

[Sibley]

It's the damn humidifier. I don't remember it being that loud last year. Hanging out upstairs is illuminating at times.

Sounds like you have a "water hammer" issue. Basically the solenoid valve in the humidifier closes very quickly and all the energy of the flowing water is transferred to the pipe. 

they make water hammer arrestors, basically an air bladder, that compress and absorb the energy preventing it from being transferred to the piping/tubing. I've heard people also partially close the valve on that kind of appliance to slow the flow of water and reduce the energy transferred.

I wish the furnace humidifier worked! It doesn't. No, this humidifier is the portable one I put in my bedroom a few days ago. I suspect that the rubber on the tank cap is drying out as it seems to be sticking. So when it does release water into the bottom of the humidifier it's making a ton of noise between the water itself and the air going into the tank to equalize pressure. When I'm downstairs that noise is also echoing through the floor and amplifies it. Overall its working, just noisy, so as long as it doesn't wake me up at night or bother me unduly I'll just leave it.

Though if anyone has any suggestions on how to solve this, please share!

[Linea_Norway]

Dried out rubber could be treated with some vegetable oil to make it smooth again. That worked well in our handhold vaccuum.

Can you humidify in some other way? Like hanging a water container on a radiator, or on top of one. Or a wet cloth.

Or do without a humidifyer. We have really low humidity every cold winter, but don't use a humidifyer.

[former player]

Can you get the furnace dehumidifier working?  That would seem to be the best long-term solution.

[BudgetSlasher]

It's the damn humidifier. I don't remember it being that loud last year. Hanging out upstairs is illuminating at times.

Sounds like you have a "water hammer" issue. Basically the solenoid valve in the humidifier closes very quickly and all the energy of the flowing water is transferred to the pipe. 

they make water hammer arrestors, basically an air bladder, that compress and absorb the energy preventing it from being transferred to the piping/tubing. I've heard people also partially close the valve on that kind of appliance to slow the flow of water and reduce the energy transferred.

I wish the furnace humidifier worked! It doesn't. No, this humidifier is the portable one I put in my bedroom a few days ago. I suspect that the rubber on the tank cap is drying out as it seems to be sticking. So when it does release water into the bottom of the humidifier it's making a ton of noise between the water itself and the air going into the tank to equalize pressure. When I'm downstairs that noise is also echoing through the floor and amplifies it. Overall its working, just noisy, so as long as it doesn't wake me up at night or bother me unduly I'll just leave it.

Though if anyone has any suggestions on how to solve this, please share!

I second the thoughts of trying to recondition the rubber.

Or if you know exactly what part it is (as in you can pick it out on a parts diagram) and know the humidifier model number you might be surprised about parts availability, ereplacementparts and repairclinic  come to mind as potential sources (both of which I have bought tool or appliance replacement parts from before)

Long term, repairing or replacing the humidifier attached to the furnace is likely the best option. 

[Sibley]

Agreed re the furnace humidifier repair, but I'm honestly lazy. The drain line for it also got removed and that would be a massive pain to replace.

I will try some oil on the rubber, can't hurt.