MGD Gas Furnace
Service Manual
BURNER/HEAT EXCHANGER INSPECTION & CLEANING
Check the exterior and the interior flue gas passages of the heat exchanger for any evidence of
deterioration due to corrosion, cracking or other causes. If signs of scaling or sooting exist,
remove the burners and clean the heat exchanger as required.
Note: Under normal operating circumstances, the heat exchanger should NOT require cleaning.
If a unit requires cleaning, it indicates that there are likely operational problems such as low gas
pressure, etc. which may cause sooting. The cause of such improper operation MUST be
determined and corrected to insure continued safe, reliable operation.
INSPECTION AND CLEANING OF BURNER
ASSEMBLY AND HEAT EXCHANGER
Inspecting the burners and heat exchanger tubes requires the use of a light and small mirror on an
extension handle.
I.
Disconnect all electrical power to unit.
2.
Turn gas OFF at manual shut off valve.
3.
Disconnect gas pipe at union.
4.
Disconnect wires from gas valve, note connections.
5.
Remove screws securing the burner box cover and remove the cover, gas valve, and burner
assembly as one unit.
6.
Clean burner assembly with a stiff brush.
Note: The burner assembly is equipped with a hot surface igniter. Use extreme caution not
to damage it. This igniter is usually made of a ceramic type material, which is VERY brittle,
and breaks easily.
7. Clean interior of heat exchanger including flue gas passages by using small brushes and a
vacuum cleaner. It may be necessary to fabricate handle extensions for the brushes to reach
the areas that require cleaning. Re-inspect after cleaning and replace the heat exchanger if
defective.
8. Reinstall parts and gaskets in reverse order. Any gaskets damaged during disassembly
MUST be replaced with new gaskets.
9. Turn gas
ON
and check for leaks. Any leaks found MUST be repaired immediately.
10. Install all access panels, turn electrical power on and check furnace for normal operation.
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