OT 50 gasket problems

[Carl Webber]

I have an OT 50 that has had the tankless coil removed. When i removed it i put a new gasket on when i re-installed the cover. The gasket is meant to be put on dry. A piece of paper even comes with it that says you are supposed to stretch it to fit the cover and don't use anything but just the gasket or it will slip off when the boiler pressurizes. So after following all the instructions i have having some trouble. I pressure tested the boiler with air up to 40psi and it held that for 24 hours without any problems. I put water in the boiler and heated it up and the gasket blew out. The temp was at about 150F and the pressure was at about 20psi. I had painted the boiler before installing it so i thought maybe the new paint could be causing the issue. So, i took the cover off and removed the paint from the surface where the gasket would be on both the cover and the top of the boiler. I also used my grinder and scuffed up the cover and top of the boiler to create some friction between the metal and the rubber of the gasket. I put it back together and I made sure i torqued the bolts really tight to make sure it wasn't loose at all. I heated everything back up and it appeared to be fine. After about 24 hours i noticed the gasket starting to slip again. It is not as bad as before, it hasn't blown out, but i can see it deformed in one spot. After watching it for a while i noticed that after another 12 hours or so it was fine until the boiler reached about 190F then it would start to leak a little water.

I'm kind of stuck. I called Tarm to see if they had any advise and they couldn't help much. The guy i spoke with said that he had heard of this only once before and it was so long ago he didn't remember how the person solved the issue. Does anyone have any suggestions on how to resolve this? Has anyone had to deal with this before? How did you solve the problem?

 

[Carl Webber]

Ok, long story short the gasket had a hole in it. That poses a whole new set of problems. It appears like the cover for the tankless coil pressed the gasket against the edge of the plate steel so much that it cut the gasket. It appears the only way to fix this is going to be getting a whole new gasket. I'm going to have to be careful when i install the new gasket. The guys at Tarm said to snug the bolts but that there is no torque spec. I snugged the bolts this last time and it cut the gasket. Next time i'll have to tighten them just a little and see if it holds pressure and just keep going until it holds. Hopefully that doesn't mean tightening them until it cuts the gasket again.

 

[maple1]

Don't have any kind of clear picture in my head what this looks like - but is there maybe a burr or knife edge that needs some filing or smoothing?

 

[Carl Webber]

I figured it out. when the guy told me to snug the bolts he just meant till they were tight and i felt resistance. He didn't mean to torque them down like you would on a cylinder head for an engine. So, it appears like i was just over tightening everything. My real problem was the paint i had added to the metal was making things slippery. Because i didn't realize that i thought i needed to tighten everything more to prevent the gasket from blowing out. In doing that i damaged the gasket. I went up to the tarm place and bought a new gasket. This time I tightened all the bolts evenly and stopped when i started to feel good resistance and the gasket appeared seated. I pressurized my boiler and fired up the oil burner. The boiler came up to temp without any problems. It has been running for 2 days now with no issue. It all boils down to these old boilers are a learning experience.