hot water heater

[Maintress]

We have a 1999 Winnebago Chieftain. Our hot water heater has been running perfect but all of a sudden no water comes out of any of the hot water faucets. Seems like we are not getting any water to the tank. Tank is full. Any help on this problem?

[CLIFFTALL]

Welcome to IRV2. Do you have an outside faucet open by chance ? The one in one wet bay ?
Cliff

[toneumanns]

Have you opened the pressure relief valve on the heater to see if water comes out? If you get air leave it open until you get a stream of water.

[BFlinn181]

As Clifftall suggests, leaving outside shower valves open can cause a loss of flow. If the pressure relief valve shows water pressure, then it must be the outlet on the tank. Remove and clean the outlet hose and check for sediments. When was the last time you flushed the water heater? Sediments can build quickly. You said all the faucets are clogged, I assume you've removed and cleaned the screens on them?

[Tony Lee]

Very likely to be a collapsed check valve on either the inlet or outlet of the tank.

If you have a winterising valve on the heater, open the bypass valve and see if you get flow out of the hot taps (it will be cold though). If you do, then suspect the check valve.
BTW having the external shower taps on will just give you warm water out of the hot tap, not no water.

If yours has two check valves, then carefully so as not to scald yourself (cover the opening with a thick towel perhaps) crack the pressure relief valve. If there is plenty of flow then it will be the check valve on the outlet.