Check valve on cold line water heater?

[Roadman33]

Here's a picture of my water heater configuration. The problem I'm having is in the basement and downstairs faucets and things the cold water pipes are running with hot water. I think it's because the hot water is backflowing into the cold wire line supply line and then up into those

 

[Terry]

Can you put your hand on the cold at the wall and see if that's warm?
Normally a check valve prevents the recirc from pushing water that direction. There could also be a crossover somewhere. Sometimes at a shower.

 

[Sponsor]

 

[Roadman33]

Can you put your hand on the cold at the wall and see if that's warm?
Normally a check valve prevents the recirc from pushing water that direction. There could also be a crossover somewhere. Sometimes at a shower.

Yeah both pipes coming out of the wall there are piping hot

 

[Reach4]

Go feel the cold lines at different sinks and shower. If you find a hot cold, I think you found your crossover.

 

[Roadman33]

I think it's the kitchen sink

 

[Roadman33]

What is the expansion tank is broken? Could that be the problem?

 

[Reach4]

What is the expansion tank is broken? Could that be the problem?

I don't totally understand the question, but the expansion tank would not cause your hot cold water symptom.

The tank should be normally empty if you are running a little water. If the tank fails, or if the precharge air is set too low, the tank would not sound empty when you knock on it.

 

[WorthFlorida]

If you have one of those auto on faucets it can cause the problem. The faucet hot and cold valves are opened all the time and the auto on/off feature is a valve on the hose to the outlet of the faucet. There should be a built in check valve in the fixture but I'm not sure. If it can't be fixed install a check valve on the cold side that feeds the faucet.

 

[Roadman33]

My expansion tank is bad. It seems full of water. It also is hot on top and cold on the bottom. When I tap on it it just seems dents like it's got no air in it. Anything I should know about replacing it?

If an expansion tank does fail does it make it more likely that the check valve will stay open and that would let hot water backfill in to the system?