Ask Me Help Desk - Thermal expansion tank

Quote:

The shut off valve to heater does isolate heater and thermal tank

That's unusual. When you say you shut off the water heater, you do mean the stop valve at the water heater don't you? These are usually just before the connection to the heater.

Suggestion. Turn off the stop valves for all toilets and look at the meter.

P.S.
You don't have any kind of lawn irrigation system do you?

I see we're on the same page, Harold except I don't usually recommend touching the shutoffs to the toilets unless absolutely necessary as most of the time the packing nuts leak as a result and can be troublesome for some home owners to deal with.

The dye test will give same result and guarantees no leakers at the packing nut... at least until they have to shut the water supply off to replace the entire flush valve.. ;)

Just my humble opinion is all!

Well, I'm with you Mark, there has to be a leak and if there is no visible signs of water it must be going down the drain. Unless there is a irrigation system. Anything to find the leak.

Quote:

Quote:
Originally Posted by jlisenbe
I'll let the guys who actually know what they're doing do the rest of the talking, but I just cannot imagine how a water heater heating up and down in LOONNNGGG intervals would cause such a thing. You might try one more thing. Turn off the breaker to the hot water heater. That turns it into simply a big pipe - no more expanding/contracing. Once it cools down, see if the meter keeps turning. If it stops, then the plot really has thickened.

I did that as well. Same thing happens. Meter stops running. Left it off for an entire day. Turned back on and meter went spinning again! Crazy stuff and costing me plenty! Thanks

Just gets curioser and curioser. Turn off the breakers, keep the valve to the HW heater on, and the meter stops spinning? Wow. We might actually have proof of extraterrestrials!

Seriously, I'm looking forward to hearing the resolution of this problem. It does seem to center around the HWH being on and warm, but it would just seem to have to be a leak somewhere. Really weird.

Quote:

Turn off the breakers, keep the valve to the HW heater on

I missed that.

Tom, are you saying that if you turn off the breakers and do not close any valves, the meter stops turning?

Quote:

Originally Posted by massplumber2008

OK...

A little far-fetched here, but if you had a cross-connection somewhere where the mixing cartridge is failing (shower valve as an example) AND your toilet or toilets were leaking past the flapper you could end up wasting hot water into the toilet tanks (would arrive as cooled water)...maybe??

Try this real quick:

Drip about 20 drops of a dark food coloring into your toilet tanks and then wait an hour and see if the colored water shows up in the toilet BOWL(s). If colored water shows up in the bowl(s) then we probably found the source of the leak. If that is the issue, pop back and we'll see if we can help you to isolate the offending mixing valve!

Back to you...

Mark

Case solved. Villan is the Thermal Expansion Tank. It would build pressure as it should and as pressure dropped it sends water back to street main. Had plumber install check valve and it has stopped. $200 check valve installed and will pay for itself in 2 reading periods... or less! They are finding out all water heaters with TET will need check valves if municipality does not already have them installed at meter (a better idea). Compounded more so by elevated homes where water heater is on upper floors.

Thanks for all the input!
Tom

Thanks for the update. We always appreciate that. The odd part here is that since there was no check valve on your incoming water, there was never a need for a thermal expansion tank. They are only required when there IS a check valve. You made the correct decision in having the check installed.