OK, so I recently replumbed the house and bought a new HPWH. Everything with the HPWH seems to be working fine. My replumb was with Propex and I did a remote multi-port tee system to reduce the number of fittings. It is a 1400sq ft 3 bd, 2 bath house. I've attached a picture of the tee's and these are located under the bathrooms, which share a wall. My supply lines are 3/4" from the WH, with a straight run of about 40 feet from the heater. Now, first thing we noticed was that waiting for hot water to arrive is significantly longer than it was for the T&B galv system I replaced. It was my understanding remote manifold system should not be much different than T&B for hot water delivery.

The other thing we noticed was that the shower water is mostly lukewarm once up to temp. Turning on the lav hot water will make the shower water very hot, and the lav will run very cold water. If the lav is turned off, the shower will begin to cool to lukewarm again. If the shower is turned off, the lav will eventually begin to run hot water again. My other bathroom is being renovated and simply has copper stub outs and a test plug on the shower valve, so I cannot test any of those to see if I'm having problems with them, too.

I'm looking for any theories here. I just don't get it and the wife is wanting me to call a plumber to have them look over my piping. Why would turning on hot lav make shower hotter, but run the lav as very cold water?

Please help me troubleshoot this!

quote; Why would turning on hot lav make shower hotter, but run the lav as very cold water?

That is enigmatic, but it could have something to do with the types of faucets you have. As for the time for the hot water to arrive, the pipng may be longer since it has to get to the manifold then to the faucet, which may be more than when it went directly from the heater to the faucet.

Try getting rid of the test plug. If the valve has integral stops close them.

Great ideas. I'll put in the cartridge and hope that fixes it!



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