Hi,
I've got an old water boiler furnace. There's a crack in the outer metal of it. You can see the flames by the crack and the metal becomes orange when it's hot. I asked advice to a technician on how to fix this and he said that usually they put a fire proof panel over the crack from the inside of the furnace. They use some kind of cement to "glue" the panel.

Do you know what are the exact names for these materials (the panel and the cement) and where they are available for purchase?

If you really have the desire to repair this just go to any heating supply house and they will be able to help you. Some of the items that are used are wet packs,combustion chamber brick, (special hi temp bricks), and a high temp cement product carried under many different names.These items are used to repair a crack in the combustion chamber depending upon the circumstances.

Thanks hvac1000,

So I would go and buy a "wetpack", cut the desired dimensions in the "fabric". Apply the fabric to the side of the chamber where the crack is. Let dry. Is that it? Or any other steps I've forgot?

Is it very expensive to buy a wetpack? Could I just fill the crack with high temp cement?

Best regards,
Frank

I am not there Frank so I cannot see exactly what you are talking about. If you do not feel comfortable doing the repair then call a professional. A wet pack is not a fabric so to speak. It is a liner material they use in boilers etc. They use it to bulid or repair fire boxes or combustion chambers. Hi temp cement is used for small cracks.

I want to do it myself, so that's why I'm asking questions. I'm conscious that there's a risks to work on a furnace. I'm also conscious that if I prepare well and ask the right questions to the right people and that if I read the right information, the risks are taken care of.

The crack is about 3 inches long and 1/32 inch wide (only at the center).

Is this a boiler that heats hot water and circulates in your home to heat it or a regular furnace that blows hot air into the home ?

It's a boiler that heats hot water and circulates it in the home to heat it.

OK what I told you is correct. You cannot repair a crack in a hot air furnace with the directions I gave you and I was checking to make sure it is a boiler.Good luck with your project.

I have a Weil Mclaine boiler. I brush it out annually then pull the burner and sweep out the debeis that falls into the fire box. Each year the line (wet pack) has more areas of thinning or concern. I found the replacement part numbers but how do I install the pack? Do I simply wet it and place it. Do I somehow glue it in? I am referring to the floor and rear refractory.. I have had the boiler apart but have not removed the old pack.