Wood Stove Thermometers

Where to mount a thermometer

A magnetic thermometer goes either on the stove top or on the connector pipe roughly 18 inches above the flue collar — pick one spot and learn what that particular stove reads there, because the same gauge shows different numbers in different positions. On a double-wall connector, a surface magnet reads the cool outer wall rather than the flue gas, so it will under-report badly; use a probe instead. A probe needs a small hole drilled in the connector pipe, so fit it before the pipe is fully assembled if you can, and never drill into a chimney liner or class-A chimney.

Reading the numbers

Follow the ranges printed on your gauge and in your stove's owner's manual rather than a figure from elsewhere — surface and flue-gas readings are not interchangeable, and a probe reads considerably higher than a magnet on the same pipe. Running low for long stretches is what produces creosote, so a thermometer is as much a chimney-safety tool as an efficiency one. If yours reads persistently cold, the fuel is the usual cause: check the wood with a moisture meter before adjusting anything on the stove. Catalytic stoves are a separate case — the combustor has its own light-off temperature and its own probe.

Wood stove thermometer FAQs

Where exactly should the magnetic thermometer sit?

Stove top or single-wall connector pipe, about 18 inches above the flue collar. What matters most is consistency — leave it in one place so you can learn what your stove's normal running range looks like at that spot.

Surface or probe — which do I need?

A surface magnet is enough for most non-catalytic stoves on single-wall pipe. Choose a probe if you have double-wall connector pipe, where a magnet reads the cool outer skin instead of the flue gas, or if you want a faster, more accurate picture of what is going up the chimney.

Will a magnetic thermometer work on double-wall pipe?

Not usefully. The outer wall of double-wall pipe is designed to stay cool, so the reading will be far below actual flue temperature. A probe thermometer is the right tool there.

Do I need a catalytic thermometer?

Only if your stove has a catalytic combustor. It reads the much higher temperature at the catalyst so you know when it has lit off and when the bypass can be closed. On a non-catalytic stove it serves no purpose.

Why does running too cool matter?

A stove burning below its proper range smoulders instead of burning cleanly, which wastes fuel and deposits creosote in the chimney. A thermometer shows you when to open the air control rather than guessing from the look of the fire.

Do you charge sales tax on stove thermometers?

No. StoveSource charges no sales tax in any state, and orders over $250 ship free to the lower 48.

Surface, probe or catalytic

Too cool and you get smouldering, poor efficiency and creosote in the chimney; too hot and you risk overfiring and damaging the appliance. A gauge takes the guesswork out of where the air control should sit.

Surface, probe or catalytic

It is the simplest option and enough for most non-catalytic stoves. A probe thermometer reads flue gas temperature inside the pipe through a small drilled hole, which responds faster and reflects what is actually going up the chimney — useful on a double-wall connector, where a surface reading is unreliable. A catalytic probe is a different instrument: it reads the much higher temperature at the combustor and tells you when the catalyst has lit off and when it is safe to close the bypass. Use one only if your stove is catalytic.