Underfloor heating thermostat buying guide
Updated: October 2026
The controller on the bathroom wall has failed, or you are fitting a first electric mat, and the amazon.co.uk titles all promise a smart room. This underfloor heating thermostat buying guide is the order of checks before you compare brands: heat source, stated load, floor probe, finish limit, neutral, and back-box depth. The stored shelf prices on 15 October 2026 run from £10.79 to £57.99 across eleven listings. Those rows sit on the [underfloor heating thermostat comparison](/hub/thermostats/underfloor-heating-thermostat). Nothing here is a lab test, and nothing here names a winner. A qualifying purchase through our links can earn a commission at no extra cost to you.
The controller on the bathroom wall has failed, or you are fitting a first electric mat, and the amazon.co.uk titles all promise a smart room.
The controller on the bathroom wall has failed, or you are fitting a first electric mat, and the amazon.co.uk titles all promise a smart room. This underfloor heating thermostat buying guide is the order of checks before you compare brands: heat source, stated load, floor probe, finish limit, neutral, and back-box depth. The stored shelf prices on 15 October 2026 run from £10.79 to £57.99 across eleven listings. Those rows sit on the underfloor heating thermostat comparison. Nothing here is a lab test, and nothing here names a winner. A qualifying purchase through our links can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Heat source | Stated load | Floor probe | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  meross Meross MTS205 WiFi thermostat | Electric floor heating, not water-based | Not stated (5 W is the electronics) | Air and floor sensors; ohms not stated | 9.0 | about £49.99 | View offer |
| Alternative |  KETOTEK KETOTEK M9.716 programmable thermostat | Electric underfloor heating | 16 A | 3 m probe; air, floor, or both | 8.8 | about £25.99 | View offer |
| Preis-Tipp |  KETOTEK KETOTEK manual 16 A floor thermostat | Electric underfloor heating | 16 A | 3 m floor probe; ohms not stated | 8.6 | about £14.99 | View offer |
On this page
Electric mat or warm-water pipes
An electric mat is a resistive load. The wall stat switches that load, or it switches a contactor once the current is higher than the contact can carry. Warm-water pipes are a valve. The stat calls an actuator or a wiring centre, and the boiler or heat pump supplies the heat. Buy the wrong side and the relay may click while the floor stays cold. In this stored set, read the bullets rather than the attribute block. The Meross MTS205 and MTS215 say electric floor heating, not water-based. The KETOTEK M6 is the listing whose bullet mentions electric heating devices or an on/off valve actuator. The other rows are filed as electric floor heating. A title that only says thermostat does not tell you which job it can do. The longer fork is on the electric or water underfloor heating thermostat page. If the floor is a mat, the next line that matters is the load.
Load, probe, and the floor finish
Warmup’s electric-system note treats 16 A, about 3,680 W at 230 V, as the usual ceiling for one stat. Above that, a contactor is electrician work, not a second dial wired in parallel. In this file 16 A is printed on the KETOTEK dial at £14.99, the M6, the M9.716, the KTF0155A, and the KTF0163A. The GLOGLOW states 16 A and 3,600 W and has no review line. Both Meross rows leave heating current unstated, and the MTS205’s 5 W line is the electronics, not the mat. Electric floors should not run on the room sensor alone. Heatmiser’s electric-floor guidance forbids air-only control, even though Heatmiser is not a row here. A 3 m cable ships with the KETOTEK dial, the M6, and the M9.716. Only the KTF0163A prints NTC 10 kΩ, on a 2.5 m probe. Length is not resistance. A buried probe can stay only when the ohms match, which is the underfloor heating floor sensor page. Finish limits are surface temperatures: about 27 °C for timber, vinyl, or laminate, and about 29 °C as a comfort surface under BS EN 1264-2 as NHBC quotes it. A menu that runs to 50 °C or 90 °C is not a wood target. Where IP20 is stated, keep the body out of the bath or shower zone.
Neutral, box depth, and Wi-Fi band
The DEWIN, the KETOTEK dial, the KTF0163A, the KTF0172A, and both Meross rows need live and neutral, and they are not a swap for a two-wire or battery stat. The M6, the M9.716, the GLOGLOW, the Denash, and the KTF0155A leave neutral unstated. If the old stat ran on batteries, assume this shelf will not drop in until an electrician has confirmed a neutral. Depth is not one number. Heatmiser’s neoStat-e asks for 35 mm, and that figure belongs to that manual. Reviews ask for a deep box on the M9.716, about 45 mm or a spacer on the KTF0163A, and a change from 35 mm to 47 mm on one MTS205 install. A KETOTEK dial reviewer fitted 25 mm. Measure the box you have. On the DEWIN, the GLOGLOW, and the KETOTEK dial, the attribute block says Wi-Fi while the bullets describe a hand control. Prefer the bullets. App rows that mention a band, and both Meross rows, want 2.4 GHz. A new circuit, a consumer-unit change, or work in a bath or shower special location is the notification case under Approved Document P. Ask the electrician who will sign the certificate. Who can fit a thermostat in the UK is the separate note on that question.
Dial, weekly programme, or app
Once the floor, the load, and the box are known, the control style is a preference with a price. The manual rows are the DEWIN at £10.79, the GLOGLOW at £13.58, and the KETOTEK dial at £14.99, rated 4.3 from 831. They give on, off, and a setpoint, not Monday-to-Friday times. Reviewers say the dial is the wrong unit if you wanted a timer. The M6 at £24.99, rated 4.2 from 271, and the M9.716 at £25.99, rated 4.4 from 270, offer 5+2, 6+1, and 7+0 plus a manual hold. Neither bullet describes an app. The M6 is also the water-actuator listing. App rows run from the KTF0155A at £44.99 through the MTS205 at £49.99 to the KTF0172A at £57.99. The KTF0155A and the KTF0163A share one 4.3-from-1,067 review text, so that count is not two piles of evidence. The Denash at £18.37 is titled as smart, rated 3.7 from four reviews, and a UK review says it does not connect.
Common questions
Do I need a 16 A stat for an electric mat?
You need a contact rated for the mat you actually have. Sixteen amps, about 3,680 W at 230 V, is the figure many UK electric systems are built around. In this set that amp line is printed on the KETOTEK dial, the M6, the M9.716, the KTF0155A, and the KTF0163A. The Meross rows do not state a heating-load current, and the MTS205’s 5 W line is not the mat. If the mat’s total is above 16 A, Warmup’s own note moves the stat onto a contactor.
Can I reuse the probe that is already in the floor?
Sometimes, and only when the resistance matches the new stat. A 3 m cable in the box does not mean your buried probe is the same part. The only listing here that prints NTC 10 kΩ is the KTF0163A. A DEWIN review could not reuse the original probe because the impedance differed. If you do not know the ohms, treat reuse as unproven.
Why do some listings say Wi-Fi when the description is a dial?
The attribute block and the bullets were not written as one sentence. On the DEWIN, the GLOGLOW, and the KETOTEK dial, connectivity says Wi-Fi while the title and the feature bullets describe a hand control with no app and no weekly pattern. Prefer the bullets. A protocol field is not a downloadable app.
How deep a back box do these bodies need?
There is no single depth in this set. A Heatmiser manual’s 35 mm minimum is that brand’s figure, not a measurement of these housings. Reviews ask for a deep box on the M9.716, about 45 mm or a spacer on the KTF0163A, and a change from 35 mm to 47 mm on one MTS205 install. A KETOTEK dial reviewer fitted 25 mm. Measure the box you have, and allow for short factory wires.
Is a bathroom stat swap notifiable?
A new circuit, a consumer-unit change, or work in a bath or shower special location is the case Approved Document P treats as notifiable. Bath and North East Somerset still names electric floor heating in that guidance. A like-for-like replacement outside those facts is not automatically notifiable. Ask the electrician. Where IP20 is stated, the stat stays out of the wet zone.
What should the floor limit be for wood or vinyl?
Use the finish maker’s surface cap, not the top of the thermostat menu. Laminate and vinyl instructions often cite 27 °C at the contact face. A comfort surface of about 29 °C is the BS EN 1264-2 figure NHBC quotes, and it is a floor-surface limit, not the air temperature you set for the room. A menu that runs to 50 °C or 90 °C is a range the software allows.
Related pages
Sources
Public UK sources for notifiable electrical work, floor-surface limits, and electric floor heating. Listings are the amazon.co.uk captures for these eleven ASINs on 15 October 2026, not a live reload. Prices on amazon.co.uk move.
- Approved Document P (retrieved 15 October 2026)
- GOV.UK competent person schemes (retrieved 15 October 2026)
- Bath and North East Somerset, electrical safety (retrieved 15 October 2026)
- IET Wiring Matters, section 753 (retrieved 15 October 2026)
- NHBC underfloor heating (retrieved 15 October 2026)
- Warmup Pro floor finishes (retrieved 15 October 2026)
- Drayton Wiser underfloor heating note (retrieved 15 October 2026)
- Heatmiser neoStat-e V2 (retrieved 15 October 2026)