How to Troubleshoot a Vent-Free Wall Heater

Vent-free gas heaters typically use electric blowers and thermostats to regulate the amount of heat discharged into your home. They don't require a chimney or wall vent to release combustion gases outside. These sealed units operate using natural gas or propane. As a safety precaution, vent-free wall heaters generally have a system that senses when oxygen levels in the room are too low and shuts off the gas supply automatically. Occasionally, you may have problems with the operation of your wall heater. Troubleshooting may resolve these issues without a call to a technician.

Pilot Ignition Problems

Step 1

Turn off the power to your wall heater, and check that the ignitor cable is attached to the electrode.

Step 2

Reconnect the cable to the electrode if necessary. Make sure there are no pinches or tears in the cable and that the cable is dry.

Step 3

Check the gas supply valve and the shutoff valve on your heater. Make sure both are in the open position.

Step 4

Ensure that the temperature control knob is in the pilot position. Press the control knob in fully while igniting. Hold the control knob in for at least 30 seconds after igniting the pilot light.

Step 5

Turn off the heater if the pilot won't stay lit. If the pilot assembly or burner is clogged by dust, lint or hair, the heater may not ignite.

Step 6

Clean the pilot and burner using a vacuum cleaner set to blow or pressurized air. Alternatively, clean these using a soft bristled brush.

Step 7

Replace the thermocouple if it appears damaged or if the heater doesn't ignite after troubleshooting. A malfunctioning thermocouple prevents the pilot light from staying lit.

Step 8

Contact a technician to inspect the heater if it fails to ignite after troubleshooting. The gas regulator may be malfunctioning and must be replaced.

Burner Not Lighting or Not Staying Lit

Step 1

Turn off the heater, including the pilot, and allow it to cool for at least 30 minutes.

Step 2

Inspect the burner and the pilot area for dust and dirt. Blow air through the ports and holes in the burner and around the pilot air inlet to clear away debris. The pilot air inlet is typically located about 2 inches from where you see the flame come out of the pilot assembly. Often, a yellow-tipped flame on the pilot indicates dirt and dust in the pilot assembly.

Step 3

Contact your gas supplier if the burner isn't igniting properly after troubleshooting. Your gas pressure may be too low, or your gas regulator may be defective. Only a qualified technician can adjust or repair these problems.


Step 1

Avoid lighting any appliances, and don't use electrical switches or phones if you smell gas when the heater is turned off.

Step 2

Contact your gas supplier from outside your home, and don't try to start your heater. If you can't reach your supplier, contact the fire department to inspect your heater and your gas connection.

Step 3

Ventilate the room if you smell any odor other than gas. Cleaning supplies, paint or cigarette smoke can cause odors when you operate your heater because these fumes mix with the air supplied during combustion.