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by Ray Lawrence

Ideally, regardless of the weather, you should turn on your fuel-operated heater every month just to make sure it is working. It’s the easiest preventive maintenance around. I know that when temperatures are warm, checking your heater may not be top of mind.

However, now that the weather is changing and we are seeing lower temperatures, you’ll want to make sure your heater is ready when you need it.

In less than half an hour, you can complete a heater inspection. One thing to remember: fuel-operated heaters are dependent on your vehicle’s battery and fuel supply. Make sure batteries are fully charged and that there is fuel in your system.

While is sounds simple, a visual inspection is very important. A lot can happen to your heater in the thousands of miles you put on your vehicle between heater inspections. Common problems include damaged or crushed intake and exhaust pipes and loose fuel metering pumps, which can result in improper fuel metering pump angles. When the fuel-metering pump is at the wrong angle, fuel delivery is affected and there could be problems with heater operation.

Make sure to inspect all external components of the heater including:

  • Heater casing — Is the casing intact? Is the safety screen attached?
  • Ducting — Look for crushed, damaged and missing ducting components. Make sure there aren’t any airflow obstructions.
  • Thermostat/Controller — Is the thermostat secured properly?

You also need to look under the vehicle for the following items:

  • Check the exhaust and intake tubes — They can get damaged or crushed while the vehicle is accumulating miles. Wasps have been known to build nests in exhaust tubes!
  • Inspect all fuel lines and connections — Make sure to do this all the way from the fuel tank to the fuel pump to the heater itself.
  • Check the fuel-metering pump — Make sure it is at a 15- to 35-degree angle with the suction side (tank side) down.
  • Inspect all wiring and connections — Check for looseness and signs of corrosion.

The final step in your fall PM is to test the heater. Use the following procedure:

  • Open all doors and windows
  • Turn the thermostat all the way up. If you are checking a coolant heater, make sure any shut-off valves have been opened.
  • Turn the heater on.
  • Allow the heater to run for 20 minutes. Pay attention to smoke at start up. Does the heater smoke a lot or just a little bit? Does the smoke dissipate after a couple minutes of the heater running or is it constant?
  • If the heater does not start the first time, try it again.

If the controller displays fault codes, see what they are and refer to our manuals and troubleshooting guides for assistance.

You should be able to complete this simple, yet thorough, inspection in about 30 minutes. Take 15 minutes to perform the visual inspection and between 15 and 20 minutes to run the heater. This will give you the peace of mind you need to know your heater will work when temperatures dip.

Here or some guides that can help you with your inspection and troubleshooting:

Click HERE for Airtronic D2/D4 Diagnostic and Repair Manual

Click HERE for Hydronic D5S/SC Diagnostic and Repair Manual

Click HERE for Recommended Pre-Season Maintenance for Airtronic Heaters

Click HERE for Recommended Pre-Season Maintenance for Hydronic Heaters

Click HERE for Technician Checklist

Don’t forget to look at our New Espar S2 (Click HERE) and S3 (Click HERE) heaters too!

Remember you can always call us at 800-837-3900 and we will be happy to assist you.

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