Residential steam heating boilers typically require makeup water approximately 3 to 4 times per month. If the system requires fresh makeup water more frequently a leak is generally the cause. Unfortunately most homeowners are unaware of this. If you are adding water frequently to your cast iron steam boiler (or if you have an automatic water feed valve you may be unaware of how much water the system is taking in) you will slowly create a hole or crack inside the boiler. Its an internal hole caused by oxygen corrosion. It happens to cast iron boilers when they take on a lot of fresh feed water. The oxygen boils out of the water and eats a hole through the metal right at the boiler’s water line. The water steams off and goes up the flue. You can’t see it unless you’re looking at the chimney. It looks like white smoke, but it’s not smoke it’s water vapor. To check for a hole, flood the boiler up into the header piping. You’ll know you have a problem if you see water pouring out from the bottom of the boiler. It is not safe to operate a steam boiler that has a confirmed hole or crack. In this project we removed a Burnham Independence Series 105K BTU gas fired steam boiler that was 11 years old. We installed a newer model, The Burnham SIN5 with electronic ignition. Against our advice we also installed an automatic water feeder. Sadly the client declined the installation of a water meter to monitor the amount of water the system consumes. Unless the leak or cause of water loss is resolved this brand new system will also have a decreased life.
Pipe Doctor Plumbing, Heating & Air Conditioning, Inc.
April 27, 2017