Family-owned gas fireplace repair serving Oakshire

How a millivolt standing pilot system works

A millivolt system makes its own power from the pilot. On the millivolt pilots in two vent manuals, the pilot splits into three distinct flames. One heats the thermocouple, one heats the thermopile and one reaches toward the main burner.

Each of those two parts turns the heat into a small voltage. The thermocouple's output holds the pilot safety in the gas valve, and when it fades the pilot safety drops out. The thermopile's output powers the switch or remote circuit that opens the main burner, which is why one Heatilator manual says house power on its standing pilot units serves optional accessories and warns that wiring line voltage to the millivolt valve damages it.

A fault can sit in any link of that chain, from a weak thermocouple or tired thermopile to a loose lead, a switch or the valve itself. For Oakshire homeowners, each link is tested in order before a part goes on the estimate.

Fog on the glass when the fireplace starts

Many owners see the glass fog up just after the burner lights and worry that something is leaking. The owner's manuals we have read explain it. Burning gas produces water vapor, and when the inside of the glass is cooler than the dew point, that vapor condenses on it. As the glass warms, the fog disappears.

One of them describes a second case. When air conditioning has cooled the glass, warm outdoor air inside the firebox can condense on it even while the fireplace is off. The manual answers it under the same normal-condensation heading.

Fog that clears on its own is normal operation, so it does not need a repair. It is worth mentioning at a service visit if it comes with something else, such as a flame that looks unusual or glass that sits loose. The glass seating and the burner are then checked together, since those are the parts the manuals connect to how the flame behaves.

Shutting the fireplace down for a long break

A fireplace that will sit unused for months, or while the house is empty, is best left so it cannot start by accident. The upkeep section of one manual gives that reason, to prevent unintended operation during summer months, vacations or trips, and its steps are about the controls.

A standing pilot is a separate choice. It can stay lit or be shut off for the break, and the manual for that model describes how it is shut off. On that maker's module, the off position means the fireplace ignores the wall switch and both remotes, which is why that switch matters more than a remote's own off button.

A maintenance visit just before a long absence is a good moment for this. The controls can be left in the state your model's manual describes, with a note of what to switch back on later.

• Wall controls switched off
• The module's selector switch set to off
• Batteries out of remotes and the backup pack

Clicking without a flame on an electronic system

On an electronic ignition fireplace, the clicking is the igniter sparking at the pilot. If the pilot does not light, the module does not spark forever. The electronic controls in the manuals we have read spark for a set time, then lock out and signal the fault, and one system also locks out after repeated failed attempts to relight a pilot lost during operation.

Resetting again and again is not the answer. Heat & Glo warns not to cycle its module's selector switch more than once within five minutes, because gas may accumulate in the firebox, and to call a qualified service technician instead.

Our technician follows the maker's lockout table in order. The checks run through gas reaching the pilot, the spark landing in the path of the gas, the ground to the chassis and the valve itself, and the part that fails its check is the one named on your estimate.