Propex HS-Series Heater One Flash Fault Code

Propex heaters are designed to be a safe and reliable source of heat for your application. If mounted in a non-stationary vehicle, the units are subject to vibration and exposure to all types of environments. Because of this, Propex designers err on the side of caution and create distinct operating parameters for the heating units. If the heater's electronic protection system senses that the unit is outside safe operating parameters, a fault code will flash on the thermostat and the unit will shut down for inspection.

This article is for the Propex one flash fault code. If your thermostat indicator light is continually flashing a single flash between pauses, this article is for you.

 

Step One

The first thing to do is reset your unit from the thermostat. You can review that procedure here.

If the one flash code persists, please proceed to step two below.

 

Step Two

Confirm your propane tank valve is open. Most propane tanks have an on/off valve on the tank and, if it is closed, propane will be unable to flow to your unit.

 

Step Three

Make sure you have propane in your tank. This is usually done with a gauge directly off the propane tank. Don't rely on the weight of your tank or on the last time you filled up your tank. We have also come across gauges that have either failed or read incorrectly, so be sure your gauge is accurate.

 

Step Four

Confirm that you do not have any obstructions in the gas fitting at the back of the unit or on any other fittings in the propane supply line. We have seen pieces of teflon thread tape or other sealants blocking the propane inlet when the fitting was installed.

 

Step Five

Check your regulator!  Regulators cause 95% of all one-flash codes, please do not overlook this step.

• Confirm you have a high-quality two-stage regulator. Single-stage regulators or low-quality two-stage regulators have inconsistent or fluctuating pressure, and this will cause the unit to throw a one-fault code.
• Confirm your regulator is calibrated between 11.5" - 12" of water column.

Please Note: Most off-the-shelf regulators specify that they are calibrated to a specific water column, but as with any mass-produced product, there is often variation. For example, the regulators we purchase specified to be set from the factory to 11.5" water column.  However, when we test them they range anywhere between 10"-15" inches w.c.

We manually re-calibrate every single regulator before we put them on the shelf to sell. The only way to confirm your regulator's pressure is to either purchase our pre-calibrated regulator or check yours with a manometer.

See Our Regulator Here

 

Step Six

Confirm all your propane supply lines are free of blockage and that there are no kinks in the lines. An easy way to test this is to turn your propane tank off, disconnect all the lines from your tank and appliances, and blow compressed air through the lines. If you hear air coming through the appliance side of the line, it is free of obstruction. Another way to confirm your lines are free is to tee in a pressure gauge right before the Propex. That way we know the unit is indeed getting fuel.

 

The picture above is from our repair bench and the Propex heater in in operation.

 

Step Seven

Ignitor Problems – It is possible that your ignitors are misaligned or incorrectly gapped.

Inside the unit, there are two small electric ignitors that light the propane in the combustion chamber. Two small electrodes make a spark as the heater receives propane and attempts to ignite. If they are misaligned, not gapped to 3mm, or faulty the unit will not light.

 

Listen for the clicking

Hold your ear about four inches away from the exhaust pipe that comes out the bottom of the unit. This is a stainless steel flexible tube and it should be routed out the side of your rig. In proper working order, you should hear a rapid burst of clicks and a whooshing sound indicating the unit has begun burning fuel.

If the ignitors are misaligned causing a large gap between them, the spark will either not be powerful enough to light the propane entering into the combustion chamber, or the spark will arc in the wrong spot. This errant arc will often occur from the ignitor wire terminal to the metal case because this is the closest ground. (picture below). 

When you are hearing the clicks look here to see if you have an arc. If you see this, the unit will need to be sent in for servicing. (NOTE: HS2211 ignitors can be field serviced. Please see our FAQ on this procedure here.)

 

The last thing to check before contacting us at support@propexnorthamerica.com is that the ignitor wire to the circuit board is secure.

If this connection is solid and you still do not hear any clicks your main circuit board may be bad and may need replacement.

If you have followed all the steps above and are still experiencing a one-flash fault code, please email us at support@propexnorthamerica.com for help.