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Moisture meter for firewood

Updated: October 2026

A load of logs has arrived, the stove manual talks about dry wood, and someone has told you the figure is 20%. That number is a burner target wherever HETAS is speaking, and it is a sales cap only under the England regulations. A moisture meter for firewood can show which side of that line a freshly split face sits on. It cannot certify the load, and a green light is not the Ready to Burn mark. The listings are in the [wood moisture meter comparison](/hub/measuring-equipment/wood-moisture-meter). Products Compared used GOV.UK, the 2020 England regulations, HETAS and Woodsure on 16 October 2026. There was no lab test. A qualifying purchase can earn a commission at no extra cost to you.

A load of logs has arrived, the stove manual talks about dry wood, and someone has told you the figure is 20%.

Our top picks

TopTes TopTes TS-630

Best overall

TopTes TopTes TS-630
9.2/10about £25.99
View offer
Valiant Valiant FIR421

Alternative

Valiant Valiant FIR421
9.2/10about £17.99
View offer
GERUI GERUI WT660-1

Preis-Tipp

GERUI GERUI WT660-1
8.6/10about £10.99
View offer
On this page
  1. 1.The 20% figure, and where it binds
  2. 2.How to sample a stack
  3. 3.What the meter can and cannot say
  4. 4.Outside England

The 20% figure, and where it binds

HETAS tells stove owners to aim for 20% or lower and to follow the appliance manual. That advice is about how the fire burns. It is not, by itself, a statute. In England, the Air Quality (Domestic Solid Fuels Standards) (England) Regulations 2020 set a prohibited level of moisture over 20% for wood supplied for domestic combustion in volumes under 2 cubic metres. Those smaller volumes must be Ready to Burn. The test behind that certification is ISO 18134-1 or ISO 18134-2, as referred to in BS EN ISO 17225-5. Your pin meter does not perform it. The rule binds the supplier, not a householder’s driveway reading. Volumes of 2 cubic metres or more use GOV.UK’s customer notice: dry to 20% or less, calibrate, and measure a freshly split face. Those loads need the notice, not the Ready to Burn certificate.

How to sample a stack

Split a log and read the centre of the new face while it is fresh. The outside of a stack and the bark dry first. HETAS wants the middle of the pile as well as the front. Forest Research’s method takes several logs, several points, and a mean, and it still calls a resistance meter an approximation. For a household delivery, five logs, some from inside the stack, each on a fresh face, is a reasonable version. One log at 18% on the outside does not clear a centre well above 20%. Calibrate if the manual asks you to, and do not trust a low battery. Where the pins sit, and what to do when warm wood will not read, is on the how to use page.
TopTes TopTes TS-630

Testsieger

TopTes TopTes TS-630
9.2/10about £25.99
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What the meter can and cannot say

HETAS quotes wood fuel on a wet basis. Some construction meters read a dry basis, which is a higher number for the same log. Use a wet-basis or wood-fuel setting, and do not compare that percent with a building-materials mode. A colour cue is a prompt. On the Valiant FIR421, at about £17.99, reviewers use the colour change as a burn or do-not-burn glance, and the listing prints no numeric range. HETAS says Woodsure auditors use a Valiant meter at around £20. That names the brand pattern. It does not certify this shelf unit. The best wood moisture meter page separates the Valiant from meters that print a percent band.

Outside England

Woodsure says sellers who only supply Scotland are not required to certify. A Scottish supplier may still certify if they sell into England. This page does not import a matching statute for Wales or Northern Ireland, and it does not claim those nations have none. The England text is England-only. The burner target does travel. HETAS still says aim for 20% or lower, and wet wood smokes and tars the flue whether or not a certificate was required. Which meter to buy is in the buying guide.

Common questions

What moisture should firewood be?
Aim for 20% or lower on a freshly split face, on a wet basis, and follow the stove manual. That is the HETAS burner target. In England it is also the sales cap for domestic wood sold under 2 cubic metres, but the official check for that cap is a certification test, not your meter. Above 20% on a proper sample, leave the wood to season under cover.
Is 20% the law where I live?
In England, moisture over 20% is prohibited for the small retail volumes covered by the 2020 regulations, and the supplier is the person that rule is written for. The same statutory instrument is not a UK-wide sales law. Woodsure says Scotland-only sellers do not have to certify. For Wales and Northern Ireland, use the rule that applies there. Do not assume the English sales ban has been copied across.
Does my moisture meter certify Ready to Burn?
No. Ready to Burn is a scheme mark with a logo, a supplier and a certification number, based on ISO 18134 testing. A handheld meter, including one with a green light, does not issue that mark. You can use the meter to decide whether to burn a log tonight. You cannot use it to tell a customer in England that a bag is certified.
Is a green light enough?
No. A green backlight or a ready colour is that meter’s own threshold. It is not the Ready to Burn logo, and it is not a reading of 20% unless you also have a number you trust on the right mode. The Valiant’s colour cue is a burning hint. Warm wood that shows nothing is not a green light in disguise.
What if the supplier said the wood was seasoned and the meter says 30%?
A UK Valiant review recorded 29–30% on wood sold as seasoned. Keep the wood, note the fresh-split readings, and ask the supplier what they mean by seasoned. If the bag was a small certified volume in England, the dispute sits with the certification and with trading standards, not with your meter standing in for ISO 18134. One reading on a warm log is not that case.
Does this apply to briquettes and to a 2 cubic metre loose load?
The England regulations cover wood sold for domestic combustion in the volumes they define, and briquettes that are sold as a certified solid fuel follow the scheme on the pack, not a pin in a loose log. A loose load of 2 cubic metres or more uses the GOV.UK customer notice: dry to 20% or less, calibrate, measure a fresh face. It does not use the small-volume certificate. Your meter can inform that drying. It does not replace the notice.

Related pages

Moisture meter comparison

Wood moisture meter

Best wood moisture meter UK: logs, walls, or a pad

Wood moisture meter buying guide: job, then sensor

How to use a wood moisture meter before you trust it

Pin vs pinless moisture meter: which one marks wood

Sources

Public UK sources on wood fuel moisture in England, meter limits, and damp in buildings. Prices, stars, and review counts are the amazon.co.uk listing figures in this set. Prices move. There was no laboratory test and no oven-dry calibration. Last checked 17 October 2026.

  1. GOV.UK, selling wood for domestic use in England (retrieved 16 October 2026)
  2. SI 2020/1095, Air Quality (Domestic Solid Fuels Standards) (England) Regulations 2020 (retrieved 16 October 2026)
  3. GOV.UK, customer notice for wood sold in volumes of 2 cubic metres or more in England (retrieved 16 October 2026)
  4. HETAS, how to check firewood moisture content (retrieved 16 October 2026)
  5. Forest Research, a simple method for testing moisture content (retrieved 16 October 2026)
  6. Historic England, assessing damp in historic buildings (retrieved 16 October 2026)
  7. Historic England, measuring moisture content in historic building materials (retrieved 16 October 2026)
  8. Woodsure, Scotland and the burning report on fuel quality (retrieved 16 October 2026)