I just bought a house with a 50+ year old boiler. Works fine but is inefficient. The expansion tank seems ok but, how do I check it for proper operation? Also, there is no flu dampner or air bleed system. Should these be installed for better overall efficiency?
The damper I would consider a necessity. It’s used to control the amount of smoke and heat going up the chimney, and it’s difficult to “tune up” your boiler without it. Draft is one of the most important things to control and adjusting it is part of a normal maintenance tune up routine. Get one on there. Only way I’m aware of to check the expansion tank is to check it’s pressure and be sure it is properly pressurized and also be sure it’s not corroded or blocked at the connection and make sure it never leaks. Most tanks for boilers come from the factory pressurized at around 12 to 15PSI. Air bleeds on the return lines are practically required for proper purging of the system if it ever needs it such as when you shut down the boiler for any work or cut off the water supply and drain it out. It’s also a good idea to have coin vents on the loops as well. Installing a Auto-Vent on the return side and even supply is a good idea along with regular boiler drain valves. When boilers reach such advanced ages as yours, you run the risk of the firebox eventually collapsing or leaking among a host of other potentially serious problems. Boilers in my opinion that are over 20 years old really should just be replaced with something new and higher efficiency. It’s amazing IMO that the thing is even still working OK at 50 years old!!