In gas operated fireplaces and space heaters such as those manufactured by Empire Comfort Systems, a malfunctioning thermocouple could mean you're in for a cold night. A thermocouple operates as a safety device in a gas-fired appliance, serving as a sensor between the pilot light and the gas control valve. If the thermocouple senses that the pilot isn't on, it tells the gas valve not to open, thus preventing a dangerous buildup of gas. Although these simple devices do fail and require replacement, correct operation of the appliance can occasionally be restored by a thorough cleaning.
Things You'll Need
- Old toothbrush or other small, soft brush
- Open-end wrenches
- Fine steel wool
- Emery cloth or fine sandpaper
- Small metal pick or screwdriver
Turn off the power or unplug the unit if the heater has an electrical connection. Remove the louvers or cover plate to gain access to the gas control and burner assembly. Turn off the gas supply at both the gas inlet and the gas control valve.
Clean any accumulated dust or debris from the gas control valve and pilot assembly as well as the surrounding area with a toothbrush or other small, soft brush. Ensure that both ends of the thermocouple are clean and accessible.
Loosen the attachment nut that holds the thermocouple into the control valve. Utilize an open-end wrench that fits the nut exactly so as not to damage the nut. Unscrew the attachment nut and pull the thermocouple power unit connector contact from its seat in the gas control valve.
Loosen the nut that holds the sensing element end of the thermocouple to the pilot assembly. Remove the thermocouple from the unit, being careful not to damage the thin copper tubing. Some sensing elements are held in with a clip or sleeve rather than a nut, in which case it is necessary to carefully pull the element out of the clip or sleeve in order to remove the thermocouple.
Remove soot or other combustion byproducts from the thermocouple sensing element with fine steel wool. Utilize emery cloth or fine sandpaper to gently clean the small metal button of the power connector contact on the other end of the thermocouple. Insert a metal pick or small screwdriver carefully into the hole in the gas valve where the thermocouple attaches and gently clean the connector contact seat. The goal is to create a good electrical connection between the power connector contact and its seat without damaging the contact, contact seat or the threads in the gas control valve.
Insert the thermocouple element into the pilot assembly by attaching the clip or tightening the nut. Insert the power connector contact into the hole in the gas control valve and tighten the nut. Reposition the thermocouple tubing. Turn on the power or plug in the unit if necessary, and turn on the gas at the supply inlet and gas control valve.
Light the pilot according to the manufacturer's instructions. Check the thermocouple pilot element to make sure it is properly positioned in the pilot flame. Reinstall the louvers or cover plate. Check for proper operation of the heater.
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