This video, “How to clean a heat exchanger” by grayfurnaceman, shows the heat exchanger cleaning process on older furnaces with draft hoods. Although this style of furnace is no longer on the market, furnaces can last forty or more years, so they remain in use today. More generally, dirty heat exchangers work less efficiently, use more energy, and can cause the furnace not to operate.
The video begins with a simulation of a problem furnace in which the flame rolls out, causing the protective device, the rollout switch, to shut off the flame automatically. The furnace restarts several times but then shuts itself down.
Removing the appropriate covers and hood reveals the heat exchanger’s tubes and baffles, where the dust deposits form. After removing the baffles, the technician cleans the inside of the tubes using a tree brush. (As always, he checks for cracks and rust-out issues too.) The cleaning process causes rust and dust to fall onto the burners, which need cleaning after the heat exchanger. The final steps in heat exchanger cleaning are to reassemble the parts and covers and test that the furnace works correctly. Always remember to consult a professional for assistance when dealing with your heat exchanger.