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Energy Saver: Furnace, Boiler & Woodstove Combustion
(continued ...) in our second group. We are doing what we can with an older standard energy efficient machine. Heat exchanger service is just not something that is a realistic option for residential high energy efficient furnaces or boilers, unless you've been to the manufacturer's technician training school. A heat exchanger has two sides, usually separated by an aluminized carbon steel or stainless steel barrier. In the case of a boiler, the two sides separate water from the combustion process. In the case of a furnace, the two sides separate air from the combustion process. In the case of a hydrocarbon burner, it could be separating either air or water from the combustion process. Both sides of both types can accumulate debris and cause fouling.
Once again, before doing anything else, turn off the power at the breaker and shut off the fuel valve as applicable. You're going to work on your machine again *1. Just like every other discussion, I'm writing in generalities, especially about this step. Heat exchangers are going to be in all sorts of shapes and sizes. There might be plates, tubes, barrels, boxes or just about any other shape.
On the combustion side of many units, it is possible to unbolt the burner and remove or rotate it. Once out of the way, you should have access to clean out unused fuel deposits, 'lamp-black' type carbon deposits and who knows what else depending on how the fuel-air ratio was set. Heat exchanger walls are thin and sometimes coated with aluminum; be careful and gentle. You'll need a vacuum cleaner. Empty it and otherwise start with a new filter and/or clean empty canister. I will explain why in a minute. ...