Suburban RV Furnace Not Igniting – Troubleshooting Guide

suburban rv furnace not igniting

A Suburban RV furnace not igniting can bring many inconveniences, especially if you’re RVing or boondocking in cold weather. Obstructions and power supply issues are some of the more common causes of Suburban furnace problems.

The good news is you don’t need a professional technician to assess and diagnose the issue. You can consider this troubleshooting guide to help restore your RV’s space heating system and resume your merry journey.

Troubleshooting Pilot Light Ignition of Suburban RV Furnace

Diagnosing the cause of a Suburban RV furnace not lighting requires a systematic approach similar to assessing residential space heaters. One must start with the most likely reason before considering rare causes.

Here’s how to troubleshoot an RV furnace that won’t turn on or stay lit.

1. Determine the Furnace’s Power Supply.

Determine-the-Furnace's-Power-Supply

Modern RV furnaces feature an electric igniter, eliminating the need for a BBQ lighter stick or other manual lighting operations. Electricity is also necessary to operate the blower or fan.

Unfortunately, many motorhome owners often overlook this possible explanation for why a Suburban furnace wont light.

Look for an access panel on the Suburban RV furnace, remove the fasteners, open it, and inspect the wires. Watch out for frayed, cut, or damaged wires and fix them as needed.

Use a voltmeter to test the wires’ current load. If the device registers a voltage, you can cross ”power supply” off your checklist.

You might also want to check the circuit breaker for accidental tripping. Press the furnace’s reset button in the motor compartment if the issue is a tripped breaker.

2. Check the Fuel Supply.

Check-the-Fuel-Supply

Most RVers use propane to heat the cabin. And although the RV furnace might have an electronic igniter, it will still require gas to keep the burners aflame.

Sadly, some RVers also forget to turn on the gas supply. Hence, we recommend checking this component to ensure gas flows to the furnace. Buy a new propane tank if the current one is already empty.

3. Assess the Air Intake for Obstructions.

Particles can lodge into the furnace air intake, limiting the fuel supply to the burners. This observation can explain why the Suburban RV furnace won’t stay lit.

Check the air intake for dust, dirt, debris, and other matter that can obstruct air flow. Remove any particle you see and test the RV furnace for normal operation.

4. Assess the Blower’s Operation.

Assess-the-Blower's-Operation

You cleaned the air intake, and the RV furnace still doesn’t ignite. What’s next?

Check the fan and observe for anything unusual, including loud noise or no air flow. Obstructions in the blower can prevent it from spinning. Structural issues have a similar effect, inhibiting the furnace from pushing hot air through the ductwork.

Locate the RV furnace blower and inspect it for damage or clogging. Cleaning it should address the issue, although replacing it with a new one is the only solution for a damaged or faulty fan.

5. Determine the Fan Motor’s Function.

If the fan doesn’t spin, there could be an issue with the electric motor.

You can remove the device from its mounting and inspect the shaft. Try wiggling it a bit. If it feels loose, you might want to replace the furnace motor.

6. Check the Sail Switch.

Check-the-Sail-Switch

Suppose the wires, fuel supply line, and air intake are all good, but the Suburban RV furnace still refuses to ignite. In that case, you might want to check the sail switch, a small device activated by the blower to engage the fuel valve.

So, when the blower comes on but won’t ignite, you might have a faulty sail mechanism. Alternatively, dirt, fur, lint and other debris can get stuck in the sail, preventing it from operating efficiently.

Remove any particles impeding the sail’s movements. If this doesn’t solve the issue, you can replace the switch.

7. Assess the Limit Switch.

Let’s say the sail switching mechanism works perfectly. The next plausible cause is a problematic limit switch. This device receives signals from the sail component, allowing it to activate the igniter and light up the burner.

If you notice the blower turning on but the furnace releases heat from the vents before turning off, there’s a good chance you have a problem with the limiting switch.

Replacing the switch is your only way to restore the Suburban RV furnace’s optimal function, provided you cleaned the air intake.

8. Check the Igniter.

Check-the-Igniter

What if you hear the furnace clicking but not lighting? In that case, the problem could be the igniter. As mentioned, igniting the burner requires the fan to depress the sail mechanism, which, in turn, sends signals to the limiting switch.

Remove the igniter and inspect for signs of corrosion. Assess the distance between the two metal arms, which should be about an eighth of an inch. You can carefully adjust the metal rods’ position to achieve the ideal gap.

Unfortunately, a broken metal arm often requires an igniter replacement.

9. Assess the Relay.

Assess-the-Relay

Another potential reason why the RV furnace refuses to ignite (despite hearing a click) is a faulty time delay relay wire, which cannot transmit electricity to the fan motor.

Use a voltmeter to identify the faulty wires and other electrical components. For example, a non-functioning motor with an operating control board often suggests a relay wire issue.

Please note this concern only applies to pre-2001 RVs.

10. Consider a Faulty Control Board.

If everything checks out and the RV furnace still doesn’t ignite, you might have a problem with the control board. Replacing it is the most logical solution.

Conclusion

A Suburban RV furnace not igniting might look challenging to troubleshoot and diagnose. Although the motorhome space heater has a simple function, it has many components that make problem identification more demanding.

Still, employing a systematic approach can help RVers identify the exact cause of the issue, allowing them to address it spot-on.

While this guide can be an invaluable diagnostic blueprint, RV owners must consider professional assistance when all else fails or they are unsure of what they’re doing. Although costlier than a DIY approach, the solutions are more or less permanent.

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