Originally Posted by cardwellmarty
Is it a good idea to open the pressure relief valve on your water heater every time you fill it or just open the faucet? I read that opening the pressure relief valve weakens the valve over time. I know in a regular home the water heater is much larger and a little air want hurt, but in an RV the water heater can be only 6 gallons. What's the norm in filling your RV/TT water heater?
As others have correctly pointed out, it is a good idea to at least open the temperature and pressure relief valve after you have dewinterized to make "sure" you have water in the tank. We have way too many examples on this forum where a member failed to do it this way, and still had their winterization valves incorrect for normal usage, then burned up an electric element. It's why we keep this sticky thread at the top of the plumbing subforum:
as well as a warning of such in this FAQ thread and to use the temperature and pressure relief valve:
If you never winterize...or have made sure your water heater is properly dewinterized during camping season... then you can just open a faucet.
Hope this helps