Suburban water heater.

Question.Is the check valve /back flow preventer in the hot water outlet or the cold water inlet? I have been told both.

it is on the outlet

tmcran said:

Question.Is the check valve /back flow preventer in the hot water outlet or the cold water inlet? I have been told both.

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I just had to replace mine two days ago and it was on the hot water outlet.

There is a Check Valve on the City Water In Port in the UDC. This is to prevent any water from flowing back into the Fresh Water supply pipes.

There is a Check Valve on the Hot Water outlet side of the Hot Water Tank. This is to prevent any cold water from the RV's plumbing from backing into the Hot Water Tank.

SmokeyBare said:

There is a Check Valve on the Hot Water outlet side of the Hot Water Tank. This is to prevent any cold water from the RV's plumbing from backing into the Hot Water Tank.

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I am 99% sure that the check valve on the water heater is really there to prevent antifreeze (or any other fluid) from flowing back into the water heater when the water heat is bypassed.

Our check valve was replaced with a ball valve and we have had no issues with water temp.

I am not familiar with home water heater ever having a check valve on the output. Homes, do have a anti-siphon valve to prevent main line contamination.

The water system has to be a hydrostatic system, thus the pressure of the cold water entering the tank is the same as the pressure of the hot water leaving the tank.

Thanks for the replys

I have also done that many times on mine and friends trailer when the hot water was getting cold in the shower. I tell them to close the valve for winterizing.

Yep Alan, I'll agree to the anti Freeze thought. Same principal, stopping any type of fluid from traveling back into the tank.

Hot water suddenly stopped flowing from faucets; is this a checkvalve problem. (We can get cold water from faucet if we use bypass). Is it simple to replace?