Replacing Domestic Hot Water Coil Gasket

Well I just discovered that the Domestic Hot Water gasket is leaking on my DF520 and there was a lot of rust built up on all the nuts/studs as mine does not have an extended flange. I cleaned all the rust off with a wire brush and it was all surface rust.. The integrity of the metal looks fine. So I was planning on replacing the gasket on Saturday and shutting the furnace down on Friday. In the mean time I was going to start spraying the nuts with Kroil penetrating oil to hopefully loosen them up. The next option I figured would be a nut splitter or a torch. Once they are off I was planning on using new nuts and putting anti seize on all the studs. Do you guys have any other tips/suggestions?

Sounds to me like you've got it covered By the way, welcome to the FORUM

Does the gasket appear bulged or ripped? You might be able to snug the nuts and stop the leak, but only if you're lucky.

Do not start this job at 8 pm when the hardware store is closed. Good idea on the Kroil, antiseize, and new nuts...but there is always a risk one or more studs will break off. Are you prepared to drill out the old studs and tap the boiler in the event a stud breaks off?

Start spraying the nuts/studs with Kroil right now, 2-3x per day. Before you bust out the wrenches, I would heat the nut with a torch and give it another soak with Kroil as it cools.

Good luck.

Thanks so far!! It bulged at the top a little bit and it is leaking very little around a few of the studs/nuts. So that is why I am just going to replace it now as I'm not sure how old it is at this point.

I'm assumming that I would have to get new studs from an efm dealer.

The plan is to start nice and early Saturday morning, just in case I have to run somewhere as the local efm dealer is open Saturday morning.

Do you have another supplemental heat,be prepared for the worst. Do you think it would last till the spring.This is not a couple hour job ,unless you get lucky.Make sure you heat the nuts and go easy with them.

Try this part number. I think it's current. They aren't cheap.


7037017 Coil repair stud, coarse thread/pipe thread

Good luck with the repair...

Maybe want to have your welder on standby also...

Well guys, got all the nuts off and thank god only one stud broke. The old gasket pretty much broke in pieces when I took it off so it was deff shot. I got the back of the stoker cleaned up good and the back of the domestic hot water coil flange all cleaned up. Now all I have to do is go to the efm dealer and pick up a new stud in the morning, drill and tap the hole, install the stud and put the coil back in and reassemble. I will deff be putting anti seize back on them and will be checking for leaks every season when it gets cleaned. Thanks for the advice and help!! I will let you know how it turns out!!

Outstanding

Just as an update, I had one or two areas had a drop or two of water on so I had to snug the gasket up a very little more but it appears all is well!! Here are some pics when it was all removed and replaced. Now all i'm going to do is spray it with some black high heat black rustoleum and then determine if I want to put the back cover on again or not as the basement is now a little warmer since I took it off.

Good you got it going.

Couldn't tell if you applied a liberal amount of thread anti-seize paste.???

Couldn't notice any unions for next removal w/o a hacksaw.???