Mastertemp 400 rusted lower manifold bolts

[mcinlb]

During the replacement of my thermal regulator, I noticed that the two lowest manifold bolts (one on each side) look rusty.

The heater is working fine, no short cycling etc and there isn't any leaking that I can see. The manifold bypass is where it should be.

The heater is making the same noises that are on this youtube video.

Replace the bolts or leave it alone? Thanks!

 

[JamesW]

Sounds like the spring on the internal bypass is loose.

Can you look in the top inlet to see if the spring is loose?

 

[mcinlb]

Thanks JamesW, I was able to verify that the bypass plunger (round circle) above thermal regulator opening is still there. Will check the spring and report back.

 

[JamesW]

If just the bottom bolts of the manifold are rusty, you can remove one to see if there is water collecting in the combustion chamber.

You can replace it if you feel like it's necessary or you can reuse it after cleaning it up and maybe adding some antiseize compound to the threads.