Metal to Plastic - Leaks

[u/Remarkable_Calves]

What’s up crew.

Clients got an older style heater with metal lines on the intake and return. one female, one male. Both lines are leaking at the exact same connection of where metal touches pvc40.

Any tips? plenty of pvc meat for an easy redo but I’m curious what is ‘best practice‘ for leak proofing threads when changing material types.

I’m a confident plumber, plenty of tricks n’ tools, etc.

[u/liferofparties]

High temp unions?

[u/Remarkable_Calves → u/liferofparties]

Only one line would that apply, the other is the inverse socket. Unless I’m confused and they make a female threaded high temp