Allied Furnace: Clean the heat exchanger

Clean the heat exchanger on a Allied furnace: Remove the heat exchanger assembly for cleaning. Protect the floor in front of the furnace.

Homeowner with a furnace problem? Call (647) 657-2977 or book a service call — licensed technicians across Vaughan and the GTA.

Applies to: Heat exchanger cleaning

Common causes of clean the heat exchanger

• Soot or scale buildup in the heat exchanger

How to fix clean the heat exchanger: step by step

1. Turn off electrical and gas supply to the furnace.
2. Remove the burner access panel and label, then disconnect gas valve wires.
3. Disconnect the gas supply line from the gas valve.
4. Disconnect the flame sensor wire, ignitor 2-pin plug and rollout switch wires.
5. Remove the four burner assembly screws and remove the gas valve, manifold and burner box as one unit.
6. Clean the burners if needed using the burner cleaning procedure.
7. Remove the condensate trap and the flue collar. Disconnect the condensate drain tubes and the exhaust collar clamps.
8. Disconnect the combustion air inducer, pressure switch wiring and combustion air tubing.
9. Remove the junction box, wiring, primary limit and top cap as needed.
10. Remove the vestibule and heat exchanger assembly from the cabinet.
11. Backwash the heat exchanger with soapy water or steam below 275 °F (135 °C), then rinse and drain it fully.
12. Reinstall all parts in reverse order, making sure the rear baffle sits under the support at the rear of the cabinet.
13. Reconnect gas and electrical supplies, verify connections, then light the furnace and run it for 5 minutes to confirm it is clean and dry.

If the unit shows an error code, look it up: Allied Furnace codes

Models

92G1UH92G1UH0450892G1UH0451292G1UH0700892G1UH0701292G1UH0901292G1UH0901692G1UH1101692G1UH1102092G1UH1352095G1UHA93UHA95UH