Food Grade Furnace Inspection And Troubleshooting

5 January 2015
 Categories: , Blog


Whether you're using a furnace fueled by propane or wood chips, there are a few liquid fuel system problems you need to understand in order to maintain your heating system. From old style wicks to efficient burner systems, a fuel furnace can be a great way to get heat when the electricity is out or to add a natural flame flavor and effect to smoked food. 

Inspect The Chamber For Air Loss

Furnace heating potential comes from not just the fuel used, but the ability to retain heat. If your furnace is losing heat too often, food can take longer to cook and you may burn through fuel at a faster rate.

One of the biggest losses of heat comes from having the flame exposed. It happens whenever a furnace door is opened, but it can happen if the heating chamber is damaged to the point of allowing air to escape.

Place the furnace in a dark room, taking note of the exits and providing ventilation for safety. Light the flame inside the furnace, then look for any area where light escapes. If there are holes or cracks in the furnace, you should be able to see the damage illuminated by flame.

The damage can be repaired by welding a covering plate with a similar or better metal. Cast iron isn't easily welded, but steel and zinc (or zinc coated) plates can be used to cover up gaps. Make sure to leave the job to a professional welder or a Heating, Ventilation and Air Conditioning (HVAC) professional.

Fuel Leaks And Burn-throughs

After time, the fuel system can weaken due to heat and the potentially caustic nature of the fuel being used. Although this usually happens after many years of use, the danger is still worth watching out for if you notice a stronger smell of fuel or quickly dying fires.

If you're using solid fluids, inspect the furnace floor or burn pit for any eroded surfaces that could be dropping fuel away from the rest of the furnace. The pit often has a lower chamber for catching soot, which can eventually allow wood chips to fall too far to burn properly.

For liquid fuels, make sure that the burner area is unclogged. Fuel qualities change as the years go by, and some of your fuel may have had clogging sediment that built up with debris in the air over the years. You'll need to use fuel line cleaner to get the system clean again, which may require an HVAC professional's air pressure unit to accomplish.

If you need help with furnace repairs or would like advice on what to use in your unique situation, contact an HVAC professional, such as one from D & R Service Inc.