Burning Wood in a Multi-Fuel Stove: Grate or Flat Base?

A multi-fuel stove is built to burn more than one fuel, which makes it flexible. But wood and coal need different things from the stove, and getting the set-up wrong is one of the most common reasons a fire burns badly, smokes, or wears the stove out faster than it should.

If you mostly burn wood, here's what you need to know.

Coal wants a grate, wood wants a flat base

Coal and smokeless fuel need air to reach the fire from underneath. That's what the grate is for: a raised, slotted bed that lets air flow up through the fuel and lets ash drop through into the ash pan below.

Wood burns very differently. It burns best sitting on a flat bed of ash, with the air coming from above and around the fire rather than from below. A flat base lets the ash build up into a warm layer that keeps the logs hot and helps them burn slowly and steadily. With a grate and air coming up from underneath, wood can burn too fast, burn out sooner and waste heat up the chimney.

How to set your stove up for wood

Most multi-fuel stoves can be converted for wood. Depending on the make, you'll either:

• remove the grate and lay the fire on the flat base of the stove, or
• fit the flat plate or "wood burning kit" supplied with the stove, or
• close off or reduce the air coming from beneath, using the controls provided

The exact method differs between manufacturers, so check your stove's manual or ask your installer or sweep. If you've lost the manual, most makers have it online.

Once you're burning wood, leave a layer of ash in the base rather than clearing it out completely each time. A thin bed of ash helps the next fire light and burn well. You can use the fine leftover ash to clean the glass too, as we explained in our guide to cleaning your log burner glass.

Why you shouldn't burn wood and coal together

It's tempting to throw a few logs on top of a coal fire, or a few lumps of coal on a wood fire. It's best to avoid it, for a few reasons:

• They need different air. Coal needs air from below through the grate, wood needs it from above over a flat bed. Burning both together means neither burns the way it should.
• Wood ash can clog the grate. Fine wood ash can block the slots and choke the airflow that coal relies on.
• It can overheat the stove. Coal burns hotter than wood. Adding wood on top, or running both together, can push the stove beyond the temperatures it's designed for, which can damage the grate, liners and glass over time.
• It's dirtier. Mixed fuels tend to smoke more and leave more tar and soot in the flue, which means more cleaning and a higher risk of chimney problems.
• It can affect your warranty. Most manufacturers set out how each fuel should be used. Check yours.

The simple rule: burn one fuel at a time, and let the fire burn down and clear the ash before changing fuel.

Getting the best from wood

Whichever way your stove is set up, the single biggest factor is how dry the wood is. Wood above 20% moisture burns badly, smokes more and coats the glass and flue. Every net we deliver is kiln dried to under 20% moisture and Woodsure Ready to Burn certified, so it burns hotter and cleaner on a flat base.

A few habits help:

• Use kiln dried kindling and a natural firelighter to start the fire, which you'll find in our Kindling & Firelighters collection.
• Give the fire enough air to burn properly, especially at the start.
• Choose the right wood for the job. Birch lights quickly and Ash and Oak burn longer, which we cover in our buying guide.

If you're unsure how your stove should be set up, ask your sweep or installer. It takes a minute and can save your stove from damage.

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Kiln Dried Logs Jersey delivers Woodsure Ready to Burn certified firewood free across all 12 parishes.