Boiler crack ..please help...it's cold

Mikeansell56

All right, I have a Belarus hot water oil boiler that's heating radiators in my house I noticed the temperature had dropped not much it only had actually dropped 7° so I went to check the furnace and water was pouring out of it pretty good when it finally cooled off I looked and it had about a 10-in crack on the front above the firebox on the outside almost right against the front door that covers the firebox. What would cause a I guess 15-year-old oil boiler to crack out of nowhere like that. It had not been leaking. There were no warning signs it's clean on the inside and it's in has its own room which I assume would be full of smoke of the chimney were clogged. But you shouldn't assume ...,I was hoping for anybody who had any knowledge on how this could have happened so I know how to fix it. Not just fix the furnace but fix what made it happen to begin with. What can I do to prevent this from happening after I do fix the boiler? Thank you

Mikeansell56

Oh yeah if it helps to mention this when I noticed it, the radiators we're cool to the touch but the water that was leaking out of the boiler was very hot kind of like it was heating the water but not circulating I'm guessing but I don't know what would cause that. Hope that's useful

kcopp

If the boiler is cracked its done. Unfortunately there is no repairing that. 15 yrs on a cast iron boiler is not that long.

Are you the original owner/ purchaser of the boiler? You may have some recourse to get a warranty claim.

HVACNUT

There might be a prorated warranty on the block if water. Probably 15 years if steam, if that's what it is.
Like @kcopp said, there's no repair for that. JB Weld would be just delaying the inevitable. 

jesmed1

Question for the pros: has anyone tried brazing a cracked cast iron boiler? Here's a video of brazing a crack in a cast iron car exhaust manifold.

https://www.muggyweld.com/video/cast-iron-exhaust-manifold-brazing/

Steamhead

@Mikeansell56 , you described the boiler as a "Belarus". Did you mean "Buderus"? And where are you located? We might know someone who can help.

Grallert

Depending on the crack there might be a temporary fix. I've used water glass to fix some pretty substantial cracks in older boilers. 50/50. worth a try. If the casting cracked there is likely something else going on. Something bad. Sounds like the boiler ran out of water hence no heat in the living space but a hot boiler. This should never happen.
Pictures will help.

EdTheHeaterMan

It is time to get a new boiler. There is no welding/brazing/soldering cast iron that will hold water pressure under the harsh conditions of heating and cooling cycles over and over.

ethicalpaul

jesmed1 said:

Question for the pros: has anyone tried brazing a cracked cast iron boiler? Here's a video of brazing a crack in a cast iron car exhaust manifold.

https://www.muggyweld.com/video/cast-iron-exhaust-manifold-brazing/

I'm not a pro, but usually when people say "crack" around here what it really is, is a heavily rusted out area between sections, or a hole rusted right through one of them

Jamie Hall

It's done. If it is steam (you don't say) and it is a crack, not a rusted out area, there is a remote chance you could patch it to run for a short time -- weeks -- with JB Weld or something of the sort, but only if you can get it completely cool and thoroughly clean, like shiny bright. If it is hot water, forget it -- the patch won't hold. Brazing and welding cast iron is a fine art -- and while vaguely feasible on a light piece like an exhaust manifold, almost impossible on a large piece of cast iron, like a boiler casting. Just too much metal to get heated up evenly enough.

If it's a rusted out area and not just a crack, there's no hope.

And, if it is a crack, there was an underlying cause -- probably low water from a leak and a malfunctioning or non-existent low water cutoff. That needs to be investigated.