Pressure leak after heating water

[DPayne]

I have a strange leak that only happens when the hot water heater reaches completion. But, the leak occurs in the toilet...and it's cold water. It's not a lot of water but it seeps out onto the floor. I sometimes can avoid it if I turn on a faucet just before maximum temperature is reached.
Is there a pressure tube that is blocked or something I can fix??

David Payne
North Trail
Caliber Edition

 

[danemayer]

Hi DPayne,

Welcome to the Heartland Owners Forum.

The hot and cold water lines are separate, so if your seepage is caused by pressure in the water heater tank, it suggests that the hot and cold water might be mixing somewhere, or maybe the valve is weak.

In normal operation, if the pressure builds up in the water heater tank, water would come out the relief valve on the outside of the water heater. You might carefully check the relief valve operation by lifting the handle to see if water is released. CAUTION: the water will be very hot so don't use your hands to open the valve, and stand clear. If the pressure relief is not operating correctly, the water might find the next weakest link in the system.

Normally the thermostat keeps the temp from getting high enough to open the pressure relief valve. Maybe your water heater thermostat is not operating correctly and temp is getting high enough to trip the high-limit switch (ECO).

If the toilet valve is leaky, and only leaks when pressure increases, maybe the answer is simply to replace the valve.

Another thing to look at is the outside shower to make sure the faucets are turned off so the hot and cold lines don't mix behind the scenes.

Circle back around to this thread to let us know what you find.

 

[mbopp]

Seeps out onto the floor? Is it overfilling the bowl?

If the water system doesn't have any check valves on the water heater (mine doesn't) then the pressure rises on both the hot and cold side as the water heats up. As the water expands it backflows out the cold inlet on the water heater. There's an air space in the water heater to allow for this expansion. That's why stick houses with a check valve on the main water line have to have an expansion tank in the system - there's no air bubble on a residential water heater.

Sounds like either the toilet valve is leaky or the water heater is shutting down by the safety overtemp switch. What's the water temp coming out of a hot-side faucet?

 

[TedS]

As the water heats, it expands. If there is no air space in the top of the hot water tank, pressure will build throughout the system including the cold water lines because the cold water is connected to the inlet to the water heater. There is no check valve in the cold water inlet. The water pump prevents pressure from feeding back into the fresh water tank. The city water inlet has a check valve to prevent feedback into the city water. The weak link is apparently the toilet valve. The toilet water valve seal may have failed or was not installed correctly. A temporary fix would be to open the relief valve on the water heater to drain water from the top of the tank and create an air space for water expansion.

 

[WMitch]

I'm have a similiar problem. At the end of the hot water heater cycle, the pressure/tempature relief valve PTRV will "weep", as Suburban likes to call it. I have replaced the PTRV, twice, to no avial. I've also, numerous times, followed Suburban's suggestion to "burp" the hot water tank to create an air pocket in the top of the tank. This to no avial, as well. I can mitigate the situation by opening a water faucet during the heat cycle. The tempature of the water, at the completion of the heat cycle is well below the 130 degrees F that's called for. Any suggestions would be greatly appreciated!!!! Thanks in advance...

 

[danemayer]

Do you have a water pressure regulator?

 

[WMitch]

Yes, I usually install it at the water source when we camp. Thus the hose, etc are seeing the reduced pressusre.