If the pilot is turning off too, it's an indication that the Oxygen Depletion Sensor (ODS) may be clogged with dust, lint or pet hair. This happens because your Vent-free gas heater uses interior air for combustion and whatever s floating in your household air during operation is going into the heater and clogging it up.
If you still have your Owners Manual, follow the instructions for removing the front half of the cabinet, Be sure the control knob on the top is in the Off position, before removing the front half of the cabinet. Here's what you'll need to clean the interior and it's parts: A vacuum cleaner that has a hose and brush attachment, a can of compressed air with a straw nozzle (like you clean your computer with).
Once the front has been removed, vacuum all of the interior, as well as the burner, that you can gently reach with the brush attachment. Once vacuuming is complete, look at the pilot assembly (it will be next to the burner). With the can of compressed air with the straw nozzle attached, place the tip of the straw nozzle barely into the pilot opening (were the pilot flame comes out and give it a quick blast of air. Now, look down the pilot from where the flame come out and you should see a small hole in the side or top of the pilot. That's the ODS sensor. Place the straw nozzle tip just barely into that hole and give it a quick blast of air. That should blowout any debris that's clogging it.
Now, look for the Thermocouple. It will be either a stand a lone thermocouple (A thin brass rod in front of the pilot flame opening. Or wire soldered to the side of the pilot near the pilot flame tip). Trace that wire back to the control valve at the top of the heater cabinet. It's a attached to the control valve with a compression nut. Try loosening it with your fingers. If you can turn it with your fingers, it needs to be retightened with your fingers and with the appropriately sized open end wrench tighten only a quarter (1/4) turn more.
Reassemble the heater and try lighting it as you normally would. If the pilot lights and holds, wait one minute before turning it to the on position. If everything works as designed, what you just performed solved the problem. Remember to do the servicing and cleaning annually. Usually in the Fall before firing it up for the heating season.
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If the pilot is turning off too, it's an indication that the Oxygen Depletion Sensor (ODS) may be clogged with dust, lint or pet hair. This happens because your Vent-free gas heater uses interior air for combustion and whatever s floating in your household air during operation is going into the heater and clogging it up.
If you still have your Owners Manual, follow the instructions for removing the front half of the cabinet, Be sure the control knob on the top is in the Off position, before removing the front half of the cabinet.
Here's what you'll need to clean the interior and it's parts: A vacuum cleaner that has a hose and brush attachment, a can of compressed air with a straw nozzle (like you clean your computer with).
Once the front has been removed, vacuum all of the interior, as well as the burner, that you can gently reach with the brush attachment. Once vacuuming is complete, look at the pilot assembly (it will be next to the burner). With the can of compressed air with the straw nozzle attached, place the tip of the straw nozzle barely into the pilot opening (were the pilot flame comes out and give it a quick blast of air. Now, look down the pilot from where the flame come out and you should see a small hole in the side or top of the pilot. That's the ODS sensor. Place the straw nozzle tip just barely into that hole and give it a quick blast of air. That should blowout any debris that's clogging it.
Now, look for the Thermocouple. It will be either a stand a lone thermocouple (A thin brass rod in front of the pilot flame opening. Or wire soldered to the side of the pilot near the pilot flame tip). Trace that wire back to the control valve at the top of the heater cabinet. It's a attached to the control valve with a compression nut. Try loosening it with your fingers. If you can turn it with your fingers, it needs to be retightened with your fingers and with the appropriately sized open end wrench tighten only a quarter (1/4) turn more.
Reassemble the heater and try lighting it as you normally would. If the pilot lights and holds, wait one minute before turning it to the on position. If everything works as designed, what you just performed solved the problem. Remember to do the servicing and cleaning annually. Usually in the Fall before firing it up for the heating season.