rv2go wrote:
Some units have check valve in the hot water line leaving the water heater. The little plastic plunger can break, cutting off the hot water flow.
More likely it cruds up with mineral deposits and sticks closed.
THE SOLUTION
#1: (Temp or see WINTER note) Turn off water, Turn off heater, bleed off pressure, remove water line from check valve, use long noose pliers to gut the valve, re-connect and enjoy.
#2: replace check valve if necessary or add 2nd valve if you can not remove the original.
WINTER NOTE
Three water heater bypass sytems 1,2 and 3 valve, IF you have SINGLE valve and you use the WET method of winterizing you need that check vlve. If you have a 2 or 3 valve set up the check valve is not needed, nor is it needed if you use the Dry method (Weay Heay Blow the lines out, several times) or the "S" method like I do (Southern Georgia just now... Full time a HOT, water heater does not freeze, only a cold one)