Thought I would pass this along as it happened to us this weekend. Wife went inside to do something - After 38 years I have learned not to ask - and informs me that she had no hot water. So I ask you mean the water is cold? She replies no there is no water coming out of the faucet. So as we were on city water I went and checked to see if "somehow" the water had been turned off. No everything was fine there. So I ask her to try the cold side and it worked. From past experience I knew what it was.
My cruiser has the 2 valve water heater by pass with a check valve in the hot side outlet. Once before when winterizing the check valve was leaking thru - not holding - so I removed it and replaced the o ring and all was good - till now! Not having anything big enough to remove the check valve or one to replace it with and fearing the wife's response to " you can heat water on the stove" - 38 years experience . I thought what can I do for a quick fix?
The quick fix was to shut off the water and as I would be working on the water heater and it is HOT I needed to drain some out of the tank. So on my Cruiser I can drain the water heater thru the low point drains. I opened the cold side and opened the "popoff valve" on the heater and the water drained. Then I removed the Pex fitting from the check valve and the culprit was found. The check valve had came apart and the "plunger" Had came apart and when trying to use the hot water it would come out and plug the end of the Pex and stop all water flow. So I removed it put the fitting back on Shut the low point drain and "popoff valve" turned on the water And Momma was happy again!
I know this was "Long winded" but setting here in Mid Mo listening to the rain one has too much time so why not. Hope this helps someone else if your cold water flows and your hot does not.
IF MOMMA AINT HAPPY NOBODYS HAPPY - 38 years remember!
HAPPY CAMPING!!!