Cold, Hot, Cold, Hot, Cold Hot

[thiel]

Okay braintrust... here's a stumper:

When I run the hot water tap, I am getting hot water, but then it switches cold, then switches back to hot, then back to cold, etc.

This happens on ALL SINKS AND SHOWERS. I have not been hooked up to city water to try, but this definitely happens on the pump.

My 2016 Int 25FB Airstream has just a single valve to bypass the water heater (I know this is unusual, but that's the way it came) and I am certain it is in the right position.

Any suggestions?

--Thiel

[pcskier]

I suspect the mixing valve is getting gunked up and performing erratically. Take it off and clean/soak with CLR or white vinegar.

[thiel]

Originally Posted by pcskier

I suspect the mixing valve is getting gunked up and performing erratically. Take it off and clean/soak with CLR or white vinegar.

Which mixing valve? Is there a central valve?

(Note that all faucets and shower are experiencing the same issue... so it cannot be the mixing valve on any specific faucet...)

[richard5933]

There's a mixing valve on the water heater itself which is intended to prevent scalding. It mixes cold water into the hot water flow if the temp climbs too high.

Use the search box on the forum and you'll find countless threads about the hot water heater mixing valve along with various ways to solve your problem.

[thiel]

Originally Posted by richard5933

There's a mixing valve on the water heater itself which is intended to prevent scalding. It mixes cold water into the hot water flow if the temp climbs too high.

Use the search box on the forum and you'll find countless threads about the hot water heater mixing valve along with various ways to solve your problem.

AWESOME. I had no idea! Thanks!

[pcskier]

The mixing valve is on the side of the water heater inside your rig. Looks like photo below. It actually is what makes your 6 gal water heater have a ‘9 gal’ rating. It takes super hot water from the heater and mixes it with cold water to produce pretty damn hot water sent to your to fixtures.