Crack in combustion chamber
My oil fired boiler has a 1/2 inch crack in the rear corner. About a year ago when I had it cleaned, the tech said to keep an eye on it. He said if the outside covering of the boiler starts to discolor due to heat, that I would need to replace it. The boiler is 15 years old and runs fine otherwise. Can the combustion chamber be replaced or does the whole unit need to be replaced? The house is 2800 sq. Any suggestions for brands if replacement is necessary? Thanks!