Low hot water flow

What Old-Biscuit said ^^^^^^

Water heater tank HOT outlet (top line) has a check valve in the fitting on tank.

It is a cheap plastic plunger/spring/o-ring assembly that jams with crud from water heater (that white calcium that you flush out drain hole) and as it clogs up water flow out of tank reduces until NO flow.

Replace the check valve OR better yet Get rid of check valve and install another shutoff valve on hot outlet line.

Check valve is used to stop backflow into tank when WH is bypassed.
Shutoff valve replaces check valve and not more clogging of cheap plastic junk check valve.


On a side note:

Don't use that mobile guy again. IF he had no clue about 'check valve' issue then he really shouldn't be working on RV's
No HOT water flow from WH....check valve is FIRST suspect.

Could be a faulty check valve on the outlet of the HW heater.

Found this on the crossroads forum:
No Hot Water!
Mid-morning and out of the blue there was no hot water from any faucet in the RV. I opened the water heater pressure relief valve to learn that water was being supplied to the heater.
I regretted not flushing the mineral deposits from the water heater for the past 5 months. I figured the deposits had built up and clogged the heater output. I turned off the water heater and opened the low point drain to depressurize the system, once the heater drain plug was removed I flushed the deposits from the heater using a ¼” OD Teflon tube under full camp ground pressure. There were not an unusual amount of deposits. So, I bit the bullet and removed the brass check valve from the water heater output to find it in pieces.
I spent $14.00 for a cheap grey plastic check valve from the only RV place in town and screwed it into place. We re-pressurized the water system and turned the water heater on. So far, so good.
I think this check valve is just for winterizing and I am tempted to replace it with a manual shut-off valve.