Recently purchased a house with no hot water from any faucet, even though the water in the hot water tank is hot. I isolated the tank (disconnected supply / return), but still get water from the faucet hot sides (no pressure drop or pressure difference between the hot and cold sides). I assume the cold water is getting into the hot lines somewhere. I don’t see any water recirc loops under any of the sinks (nor at the water heater). I removed all three shower valve cartridges (Pfister) because I read somewhere the pressure balancer could be the culprit, but I didn’t see anything unusual, and I don’t see how the cold could get to the hot side anyway when the valves are off. Am I wrong? Any suggestions?

that is really strange..
if you have the hot water line at the heater disconnected and there was a cross connecting somewhere because you get cold from the hot side of your faucets then water should pour out of the disconnected hot water pipe?

There are shut off valves on both the supply and return lines at the tank, so I closed both before disconnecting. I suppose I could crack the return valve open to verify that it is under pressure. I'll have to swing by there later today.

40 PSI at the return (same as supply). This is after draining off residual pressure and reopening main valve.

take off the gauge and screw on a garden hose. then open the valve to see if you get a big flow or a trickle.

remember the 40PSI is static pressure. it tells you there is a cross connection but it doesn't tell you if it is 2 pipes connected together (big flow) or of a faucet is allowing water to go backwards (much less flow).

Packy, I did as you suggested. It is a "big" flow, literally no different from hooking the hose up to an outside faucet.

it almost has to be a recirc line with a bad check valve to get that kind of flow.

Yes, I agree, that makes sense, but I don’t see anything visible. I started thinking maybe there is a check valve inside the walls, so I opened up the walls below the sink and the shower valve in the bathroom furthest from the water heater, but found nothing unusual.

post a pic of the ENTIRE heater and its piping

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

I believe there used to be a water softener to the right of the water tank. As seen in the pic below, there is a shut-off valve on that loop. This is what I have been using to turn off the inside water (because it’s convenient).



Closing that valve shuts off the water to the water heater as well as all inside sink faucets and toilets. However, it turns out that only the laundry cold side is fed through this loop. For some reason, the laundry hot side is not, so closing this valve doesn’t affect the laundry hot side. This seems like a plumbing mistake to me, because clearly the laundry hot is not coming from the water heater. However, I don’t think it tells me anything about the original issue, does it?

you have a mystery wrapped inside an enigma




you will need an EXPERIENCED licensed, bonded, insured MASTER plumber on-site to resolve


it could be an expensive step by step matter starting by dissconnecting the MAIN supply pipe into the house (to eliminate a 'stolen water' cross connection (by a neighboring home)


neither you, nor the plumber, should assume ANYTHING

best of luck

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

The laundry was the issue. I cut the loop; the left line goes to the laundry hot side. The line currently going to the hot is supposed to be a hose bib out back. Go figure.

My only question now is how did someone live here for 20 years with this issue? They must have been getting hot water somehow. Anyway, I am not going to think about it anymore. Everything works now.




By the way, thanks for the replies, they kept me going. And I learned a few things from some other threads.



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