Hot water tank temperature- pressure relief valve

I just installed a Hybrid Heat element in our 6 gal Atwood. After I de-winterized for Easter weekend I was testing it out at home. The pressure relief valve was weeping pretty bad. I thought the valve was bad so I installed a new one. Sure enough that one leaks as well.
Until now I thought it was the additional Hybrid Heat element, I would never have guessed the air pocket and expansion.

Thanks for posting!