Legend 40.5 - water heater pressure/temp release valve

[fero]

Hello again,
The relief valve doesn’t close properly after engine runs more than an hour, it will leak for hours even after switching the pump off and releasing pressure by opening taps. I have a new replacement but are unable to unscrew the old one, I guess after 30 years it is pretty much frozen in. When I try to force it it looks the whole front panel is moving. I wonder if anyone had to change the relief valve and how did it go. Thanks

 

[Richard19068]

I had the same experience a few months ago
As with any other stuck fitting, use your favorite penetrating oil liberally (I like Kroil), go slowly, be patient ( maybe over a couple of days) and it will hopefully come out.

 

[jssailem]

I had success using Kroil on my 50-year-old engine. Not everything is easy. Some things will release, others will break. Take it step by step and good luck.

 

[Rich Stidger]

I had the same frozen PT- Valve on my 1997 40.5. I tried everything. I think that Kroil and PB Blaster don't work well due to the thread sealants used. Nothing would loosen it. And it's in a very tight space.
Bottom line- I ended up replacing the entire unit. And after I removed the original heater, I still couldn't get the valve loose!

 

[JoeWhite]

It is not an easy job, but i would take the water heater out of the boat then work on it. If it breaks it will not flood the boat. May be it is time for a new one.

 

[Ralph Johnstone]

Do you have an expansion tank in your system ? This absorbs the expansion of the cold water as it is heated by the AF mix in the engine. Without it, your relief valve will always leak until the overpressure is removed.

Can you try heating the fitting the releif valve is screwed into to see if that will loosen it ?

When I try to force it it looks the whole front panel is moving.

Try a backup wrench.