Airxcel RV Furnace Troubleshooting Guide

The following guide helps RV owners troubleshoot common Airxcel RV furnace problems, identify error codes, test components, and perform safe repairs. It focuses on practical diagnostics, routine maintenance, and when to contact a professional to restore reliable heating in RVs. Quick Tip: Always disconnect power and propane before servicing furnace components.

Common Symptom	Likely Cause	Quick Action
No Heat	Ignition failure, thermostat, or gas valve	Check power, thermostat, fuse; inspect igniter
Blower Runs But No Flame	Faulty igniter or gas supply	Test igniter continuity; check propane pressure
Flame But Furnace Shuts Off	Safety switch, limit switch, or vent blockage	Inspect venting and limit switch; clean burner

How Airxcel RV Furnaces Work

An Airxcel RV furnace typically uses propane combustion to heat a sealed heat exchanger while a blower circulates conditioned air through the RV ducting. Electronic controls manage the ignition sequence: a thermostat call, power to the control board, the blower pre-purge, ignition, flame sensing, and run. Understanding the ignition sequence and the role of the control board, igniter, flame sensor, gas valve, and blower is essential for troubleshooting.

Safety First: Precautions Before Troubleshooting

Before starting any troubleshooting, ensure the propane supply is turned off and the RV is well ventilated. Disconnect 12V power at the fuse or battery. Wear gloves and eye protection when handling burners or sharp sheet metal. If a gas leak is suspected, evacuate and contact the gas provider or emergency services.

Tools And Parts Needed For Common Diagnoses

Common tools include a multimeter, non-contact voltage tester, adjustable wrench, nut driver set, small mirror, flashlight, pipe thread sealant for gas fittings, and a soft brush for cleaning. Useful spare parts include replacement igniters, flame sensors, thermostats, fuses, and 12V relays. Keep manufacturer part numbers handy to match Airxcel models.

Initial Checks For No Heat Or Intermittent Heating

Start with basic checks: confirm 12V power at furnace input with a multimeter, inspect the furnace fuse, verify battery voltage (12.4–13.2V under no-load), and make sure the propane tank has supply and its valve is open. Also confirm thermostat setting and wiring connections. Many no-heat issues are simple power or fuel supply problems.

Diagnosing Ignition Problems

Check The Igniter And Flame Sensor

Locate the igniter and flame sensor near the burner assembly. With power off, inspect for cracks or damage to ceramic igniters. Use a multimeter to test igniter continuity—most igniters will show continuity as a low resistance; if open, replace it. Clean corrosion from the flame sensor with fine emery cloth if dirty.

Observe Ignition Sequence

Restore power and set the thermostat to call for heat while watching the furnace. The expected sequence: blower pre-purge, igniter glow, gas valve open, flame established, blower switches to run speed. If the igniter never glows, the control board, wiring, or igniter is likely faulty.

Interpreting Error Codes And LED Flashes

Many Airxcel furnaces display diagnostic codes via an LED on the control board. Consult the specific model manual for code definitions. Typical codes indicate ignition failure, flame loss, or faulty safety switches. Record the flash pattern (long and short flashes) and refer to the manual or the Airxcel troubleshooting chart for exact meaning.

Testing The Gas Valve And Propane Supply

If the igniter glows but no flame appears, test the gas valve and supply. Ensure the propane regulator is functioning and hoses are connected. Measure downstream pressure if a gauge is available: RV LP systems typically operate near 11 inches water column (≈0.4 psi) for appliances. A weak supply or clogged regulator can prevent ignition.

Addressing Blower And Airflow Issues

A furnace that runs but produces weak heat often has airflow problems. Inspect intake and exhaust vents for obstruction, clean the furnace filter, and check ducting for collapsed sections. Test blower motor operation by observing speeds during pre-purge and run; inconsistent speeds suggest a failing motor, capacitor, or control board issue.

Vent And Exhaust Problems

Blocked or restricted vents cause shutdowns, safety trips, or overheating. Check the combustion air intake and exhaust outlet for nesting, ice, or debris. Use a mirror to inspect the vent path and remove blockages. Replace damaged vent piping or seals that cause backdraft or improper combustion.

Thermostat And Wiring Troubleshooting

Malfunctioning thermostats or loose wiring can create intermittent heating. Verify thermostat batteries if applicable. Use a multimeter at the furnace control board thermostat terminals to confirm a call for heat (typically 12V or a simple continuity signal depending on the thermostat type). Inspect wiring harnesses for chafing or corrosion.

Limit Switches, Rollout, And Safety Switches

Airxcel furnaces include high-limit switches and rollout sensors to prevent overheating. If the furnace cycles off after a short run or shuts down then restarts, a failing limit switch or blocked heat exchanger could be the cause. Test switches with a multimeter and replace any that are open under normal conditions.

Cleaning And Routine Maintenance

Annual maintenance prevents many faults. Recommended tasks: vacuum dust from burner area and blower, clean heat exchanger fins with compressed air or soft brush, inspect and clean flame sensor, lubricate blower bearings if serviceable, and check vent seals for deterioration. Replace disposable filters regularly.

Common Model-Specific Notes

Airxcel models such as Suburban, Atwood, and standard branded furnaces share many components but differ in control board layouts and igniter types. Verify part numbers for replacement components against the furnace model and serial number to ensure compatibility. Model-specific manuals provide wiring diagrams and LED code charts essential for precise troubleshooting.

When To Replace Components Versus The Whole Furnace

Replace individual parts when diagnostics point to a single failed component (igniter, flame sensor, blower motor, or control board). Consider full replacement if the furnace has extensive corrosion in the heat exchanger, repeated control board failures, or if repair cost approaches 50% of a new unit. Newer furnaces may offer improved efficiency and quieter operation.

Professional Repair And Warranty Considerations

Check warranty status before disassembling or replacing major parts; unauthorized repairs may void warranties. For gas system repairs, certified RV technicians or licensed gas fitters should be used for safety and code compliance. Keep service records and part receipts to support warranty claims.

Spare Parts And Where To Buy

Genuine Airxcel replacement parts are available through authorized dealers, RV parts suppliers, and online retailers. Use the furnace model number and serial number to locate correct parts. Non-genuine components may fit but could lead to poor performance or safety risks.

Troubleshooting Checklist

1. Verify 12V power and fuse condition.
2. Confirm propane tank valve and regulator operation.
3. Observe ignition sequence to identify failed step.
4. Test igniter and flame sensor for continuity and cleanliness.
5. Inspect venting and combustion air intake for blockages.
6. Check blower motor operation and airflow through ducts.
7. Read and interpret control board LED diagnostic codes.
8. Test thermostat calls and wiring integrity.
9. Evaluate limit switches and safety sensors for faults.
10. Document findings and source correct replacement parts.

Useful Diagnostic Voltages And Resistances

Component	Typical Reading
Battery Voltage (Rest)	12.4–13.2 V
Igniter Resistance	Low Ohms to Continuity (varies by type)
Thermostat Call	Continuity Or 12V Signal
Propane Regulator Pressure	~11 Inches Water Column

Troubleshooting Examples With Actions

Example 1: Igniter Glows But No Flame

Likely Issues: Gas valve or regulator failure, clogged orifice. Action: Verify propane supply, check regulator and tank valve, inspect burner orifice for debris, test gas valve continuity and voltage during call for heat, replace faulty gas valve or regulator if pressure low.

Example 2: Furnace Starts Then Stops After A Few Seconds

Likely Issues: Flame sensor dirty, safety switch open, or shorted control board. Action: Clean flame sensor, check venting and limit switches, record LED code, replace control board if multiple erratic codes appear.

Example 3: Blower Runs Continuously But No Heat

Likely Issues: Thermostat short, control board stuck, or gas supply off. Action: Disconnect thermostat to see if blower stops; inspect board relays; confirm gas supply and regulator pressure.

Additional Resources And Manuals

For precise diagrams, wiring schematics, and LED code tables, consult the furnace’s owner manual or the Airxcel website. Manufacturer service bulletins also provide critical updates and recall notices. Maintain a digital copy of the manual linked to the RV records for quick reference.

Key Takeaways For Reliable Furnace Operation

Regular inspection and annual maintenance prevent most Airxcel RV furnace problems. Understanding ignition sequence and using LED diagnostic codes allows targeted repairs. Prioritize safety when working with gas and electrical components and call a qualified technician for complex gas-valve, regulator, or heat-exchanger issues.