Winterizing Question: Is My HWT Check Valve Leaking?

[TKW]

This pic is the HWT bypass set-up of my present TT. It only has one bypass valve & a check valve at the hot water outlet. Since last season, I started to blow the system clear of water before pumping anti-freeze in. After draining the HWT (with some residual water remains), compressor set at 40 psi and HWT inlet on bypass, I can hear water sloshing inside the tank. Theoretically, there shouldn't be air blowing in the tank. Do I have a leaky check valve?

[PAThwacker]

I put a new bypass on the water heater and it failed. Same setup with valve on cold and only check valve on hot. Wasted $18 and 2 gallons of antifreeze. Going to just buy more antifreeze and let it rip through city water inlet and pressurize the hot out to the shower. Via sump pump in a tub pressure

I have a dedicated sump pump for winterizing campers and boat motors.

[travisc]

I’ve had both the fresh water city check valve fail and the hoywater check valve fail- Took me two gallons to figure out I was filling up the hot water holding tank after I shut the by-pass off. The city water was kind of funny- I’d try to pressure up the system with the water pump and it would shoot out the side of the rv. Same trip the black water valve wouldn’t close.........

[TKW]

Thanks for the replies! I will go over the process again this weekend and check out the HWT drain. I actually did something stupid yesterday while pumping the pink stuff through. I forgot to shut off the outside shower faucet after blowing compress air through and went ahead pumping pink stuff. Before I knew what hit me, 2 jugs of them gone to the ground while I was inside the TT. I managed to use a spare jug to finish off all the other fixtures but it sure feels like there's some unfinished business.

[Old-Biscuit]

Remove drain plug and see if you get water/air mixture blowing out

[midnightsadie]

or your blowing way to much pressure and opening it up.

[Boon_Docker]

I would say yes you have a defective check valve.