My old Venus has developed a leak in the pressure gauge line where it's brazed onto the brass component that mates with the tee fitting (joins with one line from pump output and one line to boiler). It must be a hairline crack, as I can't see it, but a leak begins when the boiler turns on and water drops land on the boiler. Once it's hot enough, the water boils and splatters the electrical connections causing the GFCI to trip.

I found the part online, but would really like to fix what I have if possible. I've already tried reheating the joint, but it didn't work. I also considered using something to divert the water as a quick fix, but the leak has gotten worse with the work I've done, so that's out as well.

Any good ideas?

I could post a pic if that would help.

A picture would be good. However, I can say that brazing for a fix would require a total tear-apart and brazing, reheating won't do it, no matter well it's attempted. Brazing is a high temperature process, unlike soldering which can be locally-hot. However, brazing is used because of the high design pressure required. You could try a food-safe loctite product, there's lots of mention of them on h-b, just search for loctite and you'll get the number for a reasonable attempt. I'd check that out before doing any metalwork at all... good luck!

Why not simply disconnect the pressure gage line and cap the tee with a 1/8" NPT brass pipe cap and a little teflon tape ? A real good assumption is that the threads on the tee are 1/8-28 BSPP whereas the NPT cap will be 1/8"-27. So, its not an exact fit but it can work.

This can be a temporary fix until you see exactly where the leak is originating.

Thanks all - great suggestions. I'm going to look around for the Loctite tomorrow as well as a cap. Re-brazing sounds like a non-starter, especially for a component of this size and cost.

Are you sure it is braised? I had an Isomac and the capillary line was soldered into the gauge and into the fitting that screwed into the T. Solder, you could just use a butane hand torch and some silver solder. Get it hot and touch the solder to the line/fitting and it will melt and flow into the seam.

No, but I had expected that if reheated it with a torch, solder would melt, but that didn't happen. If it was solder, wouldn't i need to apply flux to clean the surfaces?