Help please with hot water issue... new TT

Also check to be sure both outside shower valves are off.

AirForce I wouldn't have thought that either but Barney says it can cause these symptoms so am inclined to believe him. I would agree about the faucet except that the cold side goes cold first then hot then cold again for good, and that would be more random if there was a problem with the faucet internals.

Good first step is to confirm proper HWH bypass settings and if that doesn't fix the issue move on to the faucet.

At first I thought about the heater bypass problem, too, but how is this causing hot water in their cold water lines? Maybe if the middle valve in the diagram was also left open some hot water could make it back to the cold side?

It sounds to me more like a problem with the faucet at the sink that is somehow mixing hot water in at the faucet. Does the sink faucet have just one handle, similar to many house kitchen faucets? Perhaps it's sticking towards the hot side a bit?

nana2callie wrote:
We do not have this issue in the bathroom sink.

You may not depending on where the HW heater is located relative to the sinks. Check for proper configuration of the winterizing valves on the HW heater.

Here's the diagram that handye9 linked to:



Water heater is on the left in this diagram.

Also check to make sure your shower faucets are both off. Not just the shut off at the shower head. Mine was like that once and I could only get cold water from hot faucets. Something to do with a safety valve that prevents just the hot being on and burning you.

We do not have this issue in the bathroom sink.

Here's a diagram of winterizing valves. Check your valves to see if they are set correctly.

Winterization valves are not opened/closed correctly.

Check to make sure the water heater is not still in bypass mode from winterization. This can cause the symptoms you are describing.
Barney