Pilot And Glass

The pilot problem

A standing pilot holds the gas valve open through a small voltage generated by a thermocouple or thermopile heated by the pilot flame.

When that component weakens with age, the voltage drops and the valve closes — so the pilot lights and then goes out.

A dirty or misaligned pilot assembly does the same thing by not heating the sensor properly.

A blocked pilot orifice, frequently from spider webbing, is a classic and is cleaned rather than replaced.

On an electronic ignition unit the fault is different: the module, the igniter or the flame sensing.

And on any of them this is gas work, which in Ontario means a certified gas technician.

Spiders

Spider webbing in the pilot orifice is a genuinely common cause of a gas fireplace that will not light at the start of the season. It is a clean rather than a part, and it is a good reason to have the unit serviced in the fall rather than discovering it on the first cold evening.

The glass

A whitish film after the first few fires is normal — it is deposit from the curing of the paint and the logs, and it cleans off with a product made for fireplace glass.

Do not use an ordinary ammonia glass cleaner, which can etch the ceramic glass.

Black sooting is different. It means incomplete combustion and it needs a technician rather than a cloth.

Common causes of sooting are logs out of position blocking the burner, an incorrect gas pressure, a venting restriction, or the wrong log set for the appliance.

The glass gasket is part of the sealed combustion chamber on a direct-vent unit, so it is checked whenever the glass comes off.

And the glass is never operated with the panel removed or loose, because on a direct-vent unit that breaks the seal.

The seasonal routine

Service in the fall by a certified gas technician, before the first cold evening when everybody calls.

Have the pilot assembly cleaned and the sensing component checked, which prevents the mid-winter failure.

Have the logs repositioned to the manufacturer diagram, which prevents sooting.

Have the venting and the termination checked, including for snow blockage in winter.

Have the combustion and carbon monoxide checked, which is the part that matters most.

And turn the standing pilot off over summer if the manufacturer allows it, which saves gas and reduces the summer deposit on the glass.