How do I use the catalytic combustor and bypass lever on my catalytic wood stove?
Engage the catalyst only after the stove is hot. Start the fire with the bypass open so smoke goes straight up the flue, burn until the stovetop hits roughly 500-600°F, then close the bypass to route smoke through the combustor. Once the catalyst lights off it reburns the smoke for longer, cleaner, more efficient burns.
How a catalytic stove earns its keep
A catalytic stove has a honeycomb combustor — coated ceramic — that lets smoke reburn at a lower temperature than it otherwise would. That second burn is where the efficiency and the long, clean overnight burns come from.
But the catalyst only works once it's hot enough to light off, and it can be fouled by the wrong fuel, so it lives behind a bypass damper you control with a lever or rod. Open bypass sends smoke straight up the flue; closed bypass routes it through the combustor.
The start-and-engage routine
Start every fire with the bypass open (lever usually pulled out or up — check your manual, they differ). Open gives you an easy light and lets the stove come up to temperature without smothering the fresh fire.
Burn on high until the stovetop or catalyst probe reaches the manufacturer's light-off temperature, generally around 500 to 600 degrees, then close the bypass. Now cut the air back to your cruising setting. You'll often see the smoke from the chimney nearly disappear — that's the catalyst working. Open the bypass again anytime you reload or open the door, then re-engage once it's hot, or you'll get a face full of smoke.
Keeping the combustor alive
A combustor is consumable — it slowly degrades and typically needs replacing every several years — but you shorten its life fast by burning the wrong things. Never run manufactured wax logs, painted or treated wood, trash, or wet wood through an engaged catalyst; the residue coats and clogs the honeycomb and it stops lighting off. Only dry, seasoned cordwood.
If your stove used to hold an overnight burn and now won't, or the combustor looks crumbled or plugged, that's usually a tired catalyst. We install and service catalytic and non-catalytic wood stoves across the mountains — call (828) 545-0525 and we'll tell you honestly whether it's a new combustor or a bigger issue.
Related questions
- How do I use the air controls on my wood stove?
- What temperature should my wood stove run at, and how do I use a stove thermometer?
- How do I get my wood stove to burn all night?
- How full should I load my wood stove?
- How do I use the damper in my wood stove's flue pipe, and when should I close it?
- How do I light the pilot light on my gas fireplace?
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