Noise from Hot Water?

[alingerfelt]

In the fall I added timers to our water heaters (2 40 gallon electric water heaters, AO Smith) and to our taco recirculation pump. The timers turning everything off at about 11 p.m. at night and turn everything back on at about 5 am in the morning. There is a check valve (believe that's what it's called) on either side of the recirculation pump. The plumbers said that this makes replacing the circulation pump easy and is how it should be done.

I've noticed since then that each night about when the hot water stuff turns off and about each morning when everything that turns on I can hear the pipes in our master bathroom area make some noise. I've read online about noises and it's nothing like a hammer. My wife hasn't even noticed. Sound more like a very faint pop (knock?). In the evening when everything shuts off, it will do it every once and while and then stop, and then in the morning, I will hear some slight noises and then nothing else.

My guess it's from the water heating up and with the recirculation pump and the expansion of the pipes but just wanted to check. It's faint and you have to really listen for it. Like I said my wife has not said anything about it.

Is there a way to make these noises go away completely or should I leave it alone? I figured the only thing to do is leave everything on 24 hours a day if it bothers me.

Thanks!

Austin

 

[Jadnashua]

Probably right about expansion/contraction. Unless the pipes are exposed and you can access them, probably not much you can do.

You should only need one check valve with the recirulation system. When it comes time to replace, they won't do that much to help. Now, a shutoff valve on either side would isolate it fine. Since the flow goes one way in the circulation loop, the check valves need to be installed so they both open with flow, and prevent back flow when not on. WHen taking the pump out, while one side might hold back water, the other side would still open.

 

[Sponsor]

 

[alingerfelt]

Re

Pipes are not exposed.

I think I had my terms wrong from what you are saying. So there is a shutoff valve on either side of the taco pump.

 

[hj]

noise

You have isolation valves on either side of the pump, but you also MUST have a check valve to prevent back flow of cold water into the system. Turning the electricity off to the heater does absolutely nothing since it would NEVER lose enough heat overnight to have to turn itself on during the night. Now, if the pump were left running, IT would cool the tank down, but without power, you would use the same amount of electricity in the morning reheating the tank to make up for the heat loss. There are some situations, but very few, where a tank timer makes sense, and even those have downsides, such as running out of hot water and having to wait for the timer to turn back on and then wait for the water to heat up.