No hot water

[Johnynorthland]

My manifold froze at 26F, make sure you can move your valves in every position.

 

[Underway]

Missilleer, I have a 2019 FBOK 336, also a full-timer, we had a similar problem with our HW. It would work fine in the kitchen or shower one time but not the next. Was hit or miss for a couple days. Once I pulled the check valve out of outlet side of the HW heater I found the plastic guts broken up and would intermittently either partially or fully restrict flow. I got the following check valve off Amazon:
https://smile.amazon.com/gp/product/B00HJ6P0Z8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I accessed the HW heater by coming through the Portside storage compartment just forward of the water control bay, just removed the screws around the aft and center walls (forward wall stay in place) and crawl through to the Portside to access the back of the HW heater.

 

[jimmoore13]

If your cold water supply line to the water heater froze, you should have ZERO water at the hot water tap. Use a sink that has a two handle faucet to be sure you are drawing "hot" only. Test.

If you have cold water at the hot water tap, then your water is not frozen, but the hot water heater is not heating it.

If you have NO water at the hot water faucet, you best resolve the frozen water line pronto, and you must be prepared for one or more cracked elbows, valves, couplers in the water line. PEX will flex a bit, but the hard plastic plumbing fittings will crack and then leak. If there's a possible freeze up, be VERY aware that there can be leaks anywhere, including in walls, in the "basement" of the rig, and so on. If these aren't caught and addressed, the flood damage could be considerable. You'd be wise to shut off the "city water" supply until you find any possible leaks.

You say you use electric only. Fire up the propane side and see if it makes hot water. If so, then you have an electrical issue.
Possible culprits:
Circuit breaker on the 120 volt electric heating element.
Failed electric heating element.
Another safety "breaker/fuse" serving the hot water heater has "popped".
A loose or disconnected wire to the electric heating element.
NOTE: If the breaker serving the hot water heating element is NOT tripped, be sure to turn it off before you start diagnostics. This shock, especially around water equipment, could knock you for a loop.

Good luck.

 

[billcf7]

FYI hot water will freeze faster than cold

 

[Buddyboy1954]

Missilleer, I have a 2019 FBOK 336, also a full-timer, we had a similar problem with our HW. It would work fine in the kitchen or shower one time but not the next. Was hit or miss for a couple days. Once I pulled the check valve out of outlet side of the HW heater I found the plastic guts broken up and would intermittently either partially or fully restrict flow. I got the following check valve off Amazon:
https://smile.amazon.com/gp/product/B00HJ6P0Z8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I accessed the HW heater by coming through the Portside storage compartment just forward of the water control bay, just removed the screws around the aft and center walls (forward wall stay in place) and crawl through to the Portside to access the back of the HW heater.

If you threaded the brass check valve directly into your water heater you can damage the water heater. There is a thing called galvanic corrosion,not sure I spelled it right but brass and the aluminum tank are not compatible with one another. Luckily for me someone on this forum pointed this out to me.

 

[missileer]

Thanks Underway. Was there a Check Valve in the cold water inlet to the water heater and did you change it?

 

[missileer]

Thanks for the info jimmoore13 It is now warm here. Been in the 50's and 60's the last week or so. We have seen no lines leaking or seen any water underneath but still have no hot water. In our bathroom our sinks have two handles and no hot water comes out of the hot water side so I'm thinking check valve. The propane fires up fine and heats the water. The electric side also seems to work. Thanks for your post.

 

[missileer]

So did you get a plastic one or how did you do this?

 

[missileer]

Thanks everyone. It was the Check Valve. I took the old one out and the guts dropped out. Put a new one in and the hot water is back. Thanks for all your input. I couldn't have done it without it.