Project "Replace Pressure Release Valve" was a complete fail

My hardware guy recommends a penetrating oil called QMaxx. It's so powerful it cannot be sold in California (US joke!)

WD40 isn't penetrating oil. get the penetrating oil of your liking (I like pb blaster if I have to buy but have better luck making my own by mixing acetone and ATF) give her a soak a few times. then heat it up a few times it will go.

heat!

PB BLASTER
Try tightening the valve a little before removal.

IF you go the heat route.......

Remove the tstat rubber cover
Remove both sets of t-stats
Pull the 120V and 12V wiring inside over to the left as much as possible away from heat


I prefer some penetrating oil, some taps with wrench/hammer just to jar it so penetrating oil can seep between thread, let soak for at least an hour ----couple shots of oil/whacks while waiting
Then try to 'tighten' it a bit before trying to loosen

A 'cheater pipe' may need to be part of the equation of removal.

That is a brass fitting in a steel insert. If you heat both the brass and steel up and then throw cold water on both, it may break free easily. Dissimilar metals absorb and give off heat differently, forcing the rust to be confused, lol.

I replaced mine yesterday as well. Never thought I was going to break it loose, but I removed the exhaust baffle and got a 12" crescent wrench on it, and it finally started to turn. Mine is only 6 years old, but it was really frozen.

Use penetrating oil not WD40 and whack it now and again for a few days. And yes heat.

Heat ! Propane torch. You don't have to go crazy with it.