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cajohnson · 04-23-2019, 08:55 AM

Flushed out the antifreeze, sanitized the fresh water system, no leaks or exploded shower heads ... but ... low pressure in the hot water side of the system.

There's pressure filling up the hot water heater but low pressure at the faucets. When running the cold water everything is normal. Pump cycles on and off to keep pressure in the system but when I do the same thing with the hot water it's slow and pump activates sporadically. When it sits for a bit (pump on) it builds up some pressure which pretty quickly dissipates once you turn it on. It's the same in all the outlets including the kitchen and bathroom sinks and inside and outside showers.

2018 23FB. I don't think I goofed anything up in the winterizing. But, then again not everything is working right. Maybe an obstruction between the pump and the hot water outlets? I would appreciate any input or ideas.

Thanks,
Craig
Missoula

abqdor · 04-23-2019, 09:22 AM

You may be having a different issue, but I wanted to throw this suggestion out because it worried me when I first started de-winterizing.

I don't know how much time you are allowing to get the hot water side to run properly, but something similar happened to me. Since you emptied the hot water tank for winterizing, there is air in the tank and lines until you completely purge all of the air from the tank, so cold starts fine, but hot spurts air and water until the tank is completely full.

daleyocum · 04-23-2019, 09:42 AM

This is almost certainly a problem with the mixing valve. This is a device that sits on the back of or near the water heater that mixes the very hot water in the water heater with cold water to produce safely hot water. It gets either corroded or clogged and thus can’t do it’s job. There are many threads about this on Airforums, just search for “mixing valve”.

This happened to me this year as well when dewinterizing and that was after just one season. Mine wasn’t all that hard to change but it’s annoying and not cheap. Some people have had success cleaning them but the vinegar trick didn’t work for me.