Faulty Plumbing Installation of New Rheem Gas Water Heater

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StoneClaw

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Last photo shows the newest modification. The new piping install was just modified today by the original installer, after 34 months, by one of their field supervisors. The three piping photos show their order respectively from original 21 year old water heater through today.

The performance problem began about 2 weeks ago when I had to keep turning the thermostat control knob up two or three times a day to get the water to a sufficiently heated temperature. The pilot wasn't going out- I would just press on the temperature control knob and that would fire it up as I increased the temp setting. Last week, their tech came and said there was a problem with the thermostat/ gas valve and he replaced them with a different thermostat model, and brand the next day. They told me they had a matching thermostat from a new water heater in their shop that they would remove and install on mine but it turned out it was different from the warrantied replacement part that arrived on my doorstep 3 days later from the original manufacturer (I can live with that. The office girl is the one who gave me the misinformation and I did not see the repair until the day after it was completed when I noticed it was a different thermostat). I was convinced that that was the the problem but their field tech told me today that it was not. The new thermostat is more basic but I lost faith in the original model that was installed 34 months ago so I'm fine without a souped-up replica that would malfunction again.

The new thermostat started underperforming within a week. I eventually increased the temperature all the way up to the "B" arrow on the knob, almost to full blast. The max temp it would heat to was 110°F at nearly the highest setting.

When the field tech arrived today he took one look and told me within 5 seconds that he knew what the problem was and he changed the piping that his guy put in 34 months ago. He said cold water was mixing in with the hot water because of the piping error but I'm wondering why it worked well for the first 34 months and then all of a sudden it didn't. The results have been pretty spectacular so far. After one hour the temp is @125•F. This water heater also provides heat to my house through the AC handler via pipes and a fan.

I'm hoping a professional here can see the obvious mistake in the old/new photo from the install 34 months ago and to help me understand how it could have worked without incident for so long and now all the sudden the deficient piping is the culprit.

Sorry I know this is lengthy. TY.1000014455.jpg1000014520.jpg

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Actually the first two photos show the thermostat they replaced. The other three photos show the old piping versus water heater install piping versus modification today.
 
The vent piping is improper. You can’t go up then back down then back up again 🫤.

That’s what I’d be concerned with the most right now. I’m surprised it’s still operating.
 
The vent piping is improper. You can’t go up then back down then back up again 🫤.

That’s what I’d be concerned with the most right now. I’m surprised it’s still operating.

Hmmm. I wonder why there weren't any symptoms until recently. It doesn't look like it complies with this standard:

"The vent must pitch upwards with a minimum slope of 1/4″ per foot. This is a minimum requirement."

Thanks for pointing that out.
 
They also reused the draft hood from the old water heater. The draft hood that is in the pictures is not the Rheem draft hood.

The middle connection that was connected to cold looks like it would be the return from the air handler. If that is the case it should be connected to the cold with check valves to prevent crossover and back feeding. The most recent repipe will have the water heater work fine but I doubt the air handler will work correctly as the cooled return water will just loop back into the air handler supply.

This is also not how I would set this up to work with an air handler. I would have a mixing valve on the domestic hot feed and crank the tank to 150°+ for the air handler.

Looks like they did not reinstall isolation valves on the air handler lines.

The new gas valve is my preferred gas valve. Simple, thermocouple not thermopile. Easy to adjust and use.

Overall not impressed with the "plumber"

As to why it was fine for 3 years, I'm not sure. Maybe there are check valves by the air handler that we can't see in the pictures that have failed.
 
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