Water heater outlet checkvalve...why?

[Maks]

Had no hot water last night. No water at all was coming out of any hot water tap in the trailer. (2017 Montana 3790rd). Cold water..no problem. Put heater bypass to ON, cold water from the hot water taps.
Something was preventing the hot water to get out. Was a hot water line plugged? After tracing the spaghetti of pipes behind the "water control panel", tried to blow back water then air back into the hot water heater. No go.
After 3 hours, gained access to the back of the water heater....no easy feat. Removed the hot outlet line and blew air through the lines to the taps.....none of those lines were plugged.
So......it had to be at the water heater itself.
Found that the hot water outlet from the heater had a check valve. Pushed the little disc into the checkvalve and it stayed where I pushed it. Without removing the brass checkvalve body, I was able to remove the small disc and stem. It didn't seem to be attached to anything. THAT had to be what was preventing the hot water from getting to the taps.
Put everything back together....filled and pressured up the system....success!!! Fired up the water heater......success again! Hot water to taps and no leaks!
All that took 6 hours of head scratching, frustration, and a few bad words.
Now.........WHY is there a check valve on the hot water OUTLET of the heater? I understand the need for a check valve on the cold inlet, but why the hot outlet? Is this something I should replace right away?

[Carl n Susan]

No need to replace *AS LONG AS* you never want to winterize the RV. Actually you can winterize but you will need another 12 gals. of pink stuff to fill the water heater.

[rohrmann]

When you put the water heater into BYPASS, this stops water from entering the water heater tank, and the check valve prevents water from getting into the tank from the hot water outlet. You do this when winterizing so the tank doesn't get filled with the pink stuff. Like Carl said, if you never winterize, you could do away with the check valve and just use another nipple in it's place. You will find, if you flush out the water heater every so often, we do it a couple times a year besides when replacing the anode, (we fulltime), you will flush out the white crud which is usually what clogs up the check valve. If it's really stuck, this is the replacement. https://www.trekwood.com/products/13...-2Mpt-x-1-2Mpt