The best heat detectors, compared.
Top pick: X-Sense XH02 Best value: X-Sense XH02 – Best value in the £15 to £18 band at about £15.29, score 77, 4.8 from 202 reviews, with no BS 5446-2 line. Updated October 2026.
A heat detector, sold on amazon.co.uk as a heat alarm, warns by temperature, so it can sit in a kitchen or garage where cooking fumes set a smoke alarm off. It responds later than a smoke alarm, so it does not replace one in a hall or a living room. Buyers are owner-occupiers who want fewer false alarms, and households in Scotland or a Northern Ireland private let who must meet a national rule. Look for BS 5446-2:2003, a sealed cell or 230 V with backup, and same-brand interlink where the law requires it. A standalone unit does not finish those interlinked installs. England and Wales texts used here do not name a heat alarm for every kitchen. Standard, power, and interlink are in the [heat detector buying guide](/hub/fire-protection/heat-detector/sub/heat-detector-buying-guide). It sounds when the air temperature rises, rather than when it sees smoke. On amazon.co.uk the same product is listed under both names. That is why it can live in a kitchen, garage, loft, or boiler room, where steam and cooking fumes trip a smoke alarm. Quality starts with the product standard, then the power supply, then interlink if the nation requires it.
A heat detector, sold on amazon.co.uk as a heat alarm, warns by temperature, so it can sit in a kitchen or garage where cooking fumes set a smoke alarm off.
32 products checked · 64 hrs invested · +22,800 readers
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Personal buying guide
Question 1 of 2
Must the kitchen alarm sound the others?
The X-Sense XH02 sits at £15.29 with 4.8 from 202 amazon.co.uk reviews, the highest star line in this set. Reviewers often say cooking no longer sets the alarm off, and they describe a small head, an easy fit and a ten-year cell, with little defect pattern in the texts that were read. The bullets call it Class A1 with an NTC thermistor, 85 dB at 3 metres, and one button that tests and silences, plus a light. They also say there is no interconnect, no app, and no compatibility with the SBS50 base station, and they do not print BS 5446-2. The box list includes a CR123A as well as the sealed-battery claim, which is an odd pair of lines on one page. In this set it is the best value in the £15 to £18 band, because it undercuts the WISUALARM on price and beats it on stars, while the top pick remains the cheaper FireAngel with the named standard. Skip it if the bedroom must hear the kitchen, because this head does not link.
Pros
Cons
Best for: You want a standalone Class A1 kitchen alarm in the mid band and you can accept a missing BS 5446-2 line.
Less suitable: You need interlink, an app, or the Kitemark number that the top pick prints.
Specifications
Common questions
Can this X-Sense join an app or a base station?
No. The listing says the XH02 is not compatible with the SBS50 and has no interconnect and no app.
What class does it claim?
Class A1, with an NTC thermistor. No degree figure and no BS 5446-2 line are in the bullets.
How loud is it?
85 dB at 3 m, with a light as well as the sound. One button tests and silences.
Across 898 amazon.co.uk reviews, the FireAngel FA6720-R is the sealed kitchen heat alarm with the longest review file in this set, at £11.97 on 19 October 2026. Reviewers often describe an easy ceiling fit, few cooking false alarms, and a cell you do not swap each year. The listing prints BS 5446-2:2003 and KM 694292, plus a silence button and a quiet test. The warranty line is five years while the title claims a 10-year battery, and the review texts include units replaced well before ten years. Several buyers say it is quieter than the older HT-630, and that the baseplate slots are awkward. The captured listing does not claim interlink, which one reviewer raises for a Scottish home. It is the top pick here when you want a named heat-alarm standard and a large UK review count on a standalone kitchen unit.
Pros
Cons
Best for: You want a sealed kitchen heat alarm with BS 5446-2 on the listing and a large amazon.co.uk review file.
Less suitable: The bedroom must hear the kitchen, or you need a warranty that matches the 10-year claim.
Specifications
Common questions
Is this a kitchen heat alarm?
Yes. The listing places the FA6720-R in dusty or humid rooms, including a kitchen, where a smoke alarm would react to cooking fumes.
Does it run on mains?
No. The alarm is supplied with a sealed battery. The title states a 10-year battery. The warranty line is five years.
Does it interlink?
The captured listing does not claim interlink. The baseplate is described as identical to the HT-630.
The Kidde Firex KF3, model 4899, is a 230 V heat alarm at £32.91 with a 9 V alkaline backup, and the listing shows 4.6 from 492 amazon.co.uk reviews. It is BSI certified to BS 5446-2:2003, with a six-year warranty and a combined test and hush control. The printed alarm size is 133 × 133 × 6 mm, which some reviewers find smaller than the head they are replacing. Buyers often use it as a like-for-like mains swap, sometimes cheaper than a trade counter. The sharp complaint is a connector that did not match an older 123/9HI base. The backup is a user-replaceable alkaline cell, so “check the battery” appears in the reviews, and the bullets do not state a universal interlink. It suits a Kidde mains replacement once you have matched the connector, and it is a costly way to buy a kitchen alarm you could have screwed up yourself on a sealed cell.
Pros
Cons
Best for: You are swapping an expired Kidde mains head and you have checked the connector against the old base.
Less suitable: You need a sealed battery for a DIY fit, or your old base is not this pattern.
Specifications
Common questions
What supply does the Kidde use?
230 V mains with a 9 V alkaline backup. It is not a sealed-battery alarm.
Which standard is on the listing?
BSI certified to BS 5446-2:2003, and CE. The warranty line is six years.
Will it fit every old Kidde base?
The bullets do not say. Reviews include both a matching swap and a connector that did not fit a 123/9HI.
The AEGISLINK AHZ-SN is a standalone heat alarm at £11.99 that states an A1-grade thermistor trigger at 54°C and an 85 dB sound. The amazon.co.uk line is 4.6 from 19 reviews. Buyers who comment describe kitchen use without toast false alarms, a large test and silence button, and fixings that include screws plus adhesive or magnetic discs. One reviewer says it is not the loudest in the house. The listing does not print BS 5446-2, and it says 10-year battery without saying the cell is sealed. Nineteen reviews are a thin base beside the FireAngel file of 898. It can suit a small kitchen if you accept that gap and you screw the base rather than relying on the pads some buyers describe.
Pros
Cons
Best for: You want a cheap standalone head that prints 54°C and you will treat 19 reviews as a limit.
Less suitable: You want the British Standard on the listing, or a sample large enough to judge early failures.
Specifications
Common questions
What trigger temperature is printed?
The bullets say an A1-grade thermistor triggers at 54°C, with an 85 dB alarm.
Does it need a hub?
No. It is described as standalone, with no base station and no smart features.
Which rooms are named?
Kitchens, bathrooms and garages. There is a large test and silence button.
The WISUALARM H01 is a standalone Class A1 heat alarm at £17.99, with 4.5 from 361 amazon.co.uk reviews. The bullets state a trigger from 54°C to 65°C and an 85 dB sound, which is more temperature detail than most rows here. Reviewers often call it small, easy and loud, and they mention the ten-year cell. A minority say the head needs a firm twist before it latches and the chirp stops. The box includes a double-sided adhesive sticker, while London Fire Brigade’s public advice is to screw a heat alarm and not to glue it. Warranty is not stated on the captured page, and the title says standalone, so it does not finish an interlinked Scottish home or a Northern Ireland private tenancy. It is a clear mid-band alternative when you want the degree range printed, and a weaker pick than the top pick if you are paying for a Kitemark number.
Pros
Cons
Best for: You want a standalone kitchen heat alarm that prints a Class A1 temperature band and you will screw the base.
Less suitable: You need interlink, a Kitemark number on the listing, or a pad-only fit.
Specifications
Common questions
What temperature does it state?
The bullets say Class A1 and a trigger from 54°C to 65°C, with an 85 dB sound.
Can you silence it without a pole?
The listing says a household infrared remote can mute it. The remote is not in the box. There is also a large test button.
Is it interlinked?
No. The title calls it a standalone heat alarm.
The BLACK+DECKER BD/MHE/FF is a mains kitchen heat alarm at £16.99, with a 9 V alkaline backup and a FastFix base. The listing claims a Kitemark to BS 5446-2:2003 and wired interlink with other BLACK+DECKER mains alarms, so one unit can sound the rest of that family. The ten-year figure is the stated life of the alarm, not a sealed cell you never touch. The amazon.co.uk line is 4.5 from eight reviews, and the saved listing does not contain enough review text for a fault list. Silence is not stated. A qualified electrician should fit any 230 V alarm, which London Fire Brigade says in its home guidance. It is a coherent specification if you are already on that mains family, and a thin evidence base if you are choosing a first heat alarm from reviews alone.
Pros
Cons
Best for: You are replacing or extending a BLACK+DECKER mains alarm circuit and an electrician is fitting it.
Less suitable: You wanted a sealed battery you can screw up yourself, or a review file you can actually read.
Specifications
Common questions
Is this battery only?
No. It is mains powered with a 9 V alkaline backup. The 10-year figure is the stated life of the alarm, not a sealed cell.
How does interlink work?
By wire, with other BLACK+DECKER mains alarms, so that when one sounds they all sound.
What certification is claimed?
Kitemark certified by BSI to BS 5446-2:2003. The base is the FastFix plate.
The BLACK+DECKER BD/BHE/10 is a sealed-battery thermistor heat alarm at £15.19, with 4.3 from 48 amazon.co.uk reviews. The listing cites BS 5446-2:2003 with CE and UKCA, and one install bullet also prints EN 14604, which is the smoke-alarm standard. Reviewers who are pleased describe an easy swap for a kitchen smoke alarm, a loud sound, and a hush of up to 10 minutes. Complaints in the saved listing include a missing mounting plate and date labels that sit awkwardly against the ten-year claim. Some buyers suspect a rebrand, which is an opinion in the reviews, not a confirmed manufacturer fact. Interlink is not stated. Forty-eight reviews show a pattern, and the file is still much thinner than the FireAngel or X-Sense lines.
Pros
Cons
Best for: You want a sealed BLACK+DECKER kitchen head at a mid price and you will check the plate is in the box.
Less suitable: You are treating EN 14604 as the heat standard, or you need a review file in the hundreds.
Specifications
Common questions
Where does the listing say to fit it?
Kitchens, garages and lofts, where cooking fumes or steam would trip a smoke alarm.
How do you hush it?
The test button includes a hush of up to 10 minutes while the alarm keeps operating.
Which standard is printed?
BS 5446-2:2003, plus CE and UKCA. The same install bullet also prints EN 14604.
The Status SSBHA1PKB5 is the lowest shelf price in this set, at £8.99, with batteries included and a title that says 10 Year Battery. The amazon.co.uk line is 3.9 from two reviews, which cannot carry a reliability claim. The captured bullets do not mention BS 5446-2, a Kitemark or UKCA, and they do not say whether the cell is sealed or a cell you replace. The listing allows a ceiling or a wall, which conflicts with FireAngel’s and Aico’s ceiling guidance for heat alarms. Interlink and a sound level are not stated. Treat the £8.99 as the bottom of the price band, and leave it when you need a printed product standard. Two reviews are not a sample you can lean on.
Pros
Cons
Best for: You have already checked a standard elsewhere and only want to see the bottom of this price band.
Less suitable: You need BS 5446-2 on the listing, a sealed cell you can name, or more than two reviews.
Specifications
Common questions
Does the listing name a British Standard?
No. The captured bullets do not mention BS 5446-2, a Kitemark or UKCA.
Can it go on a wall?
The listing says ceiling or wall, and that a professional is not required.
What power does it use?
Batteries are included. The title says 10 Year Battery. It does not say whether the cell is sealed.
The BLACK+DECKER BD/BHE/RF10-PRO is the radio heat alarm in this set, at £24.90, and the listing says it links up to 20 BLACK+DECKER CONNECTED smoke, heat and carbon monoxide alarms. It claims a Kitemark to BS 5446-2:2003, a sealed ten-year lithium cell, and a twist-on base. The amazon.co.uk line is 3.8 from four reviews, and the saved listing does not hold enough review text for a fault list. Silence is not stated. It is the row to shortlist when you already own that CONNECTED family and the kitchen has to sound the rest of the house. It is a weak default if you wanted a large UK review count, or a unit that talks to another brand. FireAngel’s own trade note says not to interlink FireAngel alarms with other makers, and nothing in this listing claims the reverse.
Pros
Cons
Best for: You already own BLACK+DECKER CONNECTED alarms and need a kitchen heat head on the same radio.
Less suitable: You wanted a large review file, or your existing alarms are another brand.
Specifications
Common questions
Will it link to alarms I already own?
Only if they are BLACK+DECKER CONNECTED alarms on RF10-PRO. The listing says up to 20 smoke, heat and CO units in that family.
Is it mains powered?
No. It uses a tamper-proof 10-year lithium battery and twists onto the base.
Is there a Kitemark claim?
Yes. The listing says Kitemark certified by BSI to BS 5446-2:2003, with UKCA and CE.
Scores use the nine amazon.co.uk listings kept on 19 October 2026. There is no laboratory test. The score is 0–100 from four parts: stars, review sample, the standard and class printed on the listing, and fit for a householder. The highest total is the top pick. The best value is the strongest listing in the £15 to £18 band that is not the top pick.
Stars
30%Amazon stars as a share of 30 points: the listing rating divided by 5, then multiplied by 30, and rounded. A high star line on a tiny sample does not outrank a larger file.
Review sample
25%Up to 25 points from the amazon.co.uk review count. 500 or more reviews score 25, 200 to 499 score 18, 40 to 199 score 12, 15 to 39 score 7, and fewer than 15 score 3.
Standard and class
25%Up to 25 points. BS 5446-2:2003 with a KM number, Kitemark, or BSI line scores 25. A class or a stated trigger without that line scores less. No standard and no class scores 4.
Fit for a householder
20%Up to 20 points for a sealed cell, a stated silence control, a British Standard on a standalone kitchen job, or a same-brand interlink when that is what the listing claims. A thin review file and a user-replaceable backup pull the mark down.
A heat alarm is for the room where a smoke alarm false-triggers. On these nine amazon.co.uk listings the shelf price runs from about £8.99 to £32.91, captured on 19 October 2026. The useful split is the standard on the page, the power supply, and whether the unit claims same-brand interlink. Class A1 or a degree figure helps only when the listing prints it. A five-year warranty is not a ten-year life, and a ten-year cell is not an interlink.
A heat detector is a heat alarm. It sounds when the air temperature rises, rather than when it sees smoke. On amazon.co.uk the same product is listed under both names. That is why it can live in a kitchen, garage, loft, or boiler room, where steam and cooking fumes trip a smoke alarm. It is the wrong device for a hall or a living room, because it responds later than a smoke alarm. Quality starts with the product standard, then the power supply, then interlink if the nation requires it.
BS EN 14604 is the smoke-alarm standard. The heat-alarm specification to look for is BS 5446-2:2003. One BLACK+DECKER heat listing prints both. The extra line does not turn the unit into the alarm for a hall.
London Fire Brigade says screw a heat alarm and do not glue it. The WISUALARM box includes an adhesive sticker, and some AEGISLINK reviews describe pads or magnetic discs. Use the screws, on the ceiling, not over the hob.
A sealed cell means you do not swap a PP3 each year. It does not mean the kitchen sounds the rest of the house. Only the two BLACK+DECKER listings here state an interlink, and only inside that brand. A five-year warranty is also not a ten-year life.
The first check is the product standard printed on the amazon.co.uk listing. For a heat alarm that standard is BS 5446-2:2003. A Kitemark, a KM number, or a BSI line is the strongest form of that claim in this set. BS EN 14604 is the smoke-alarm standard. If it appears on a heat listing, do not treat it as the heat specification. Class A1, or a stated trigger such as 54°C or a band of 54–65°C, tells you the listing has named a temperature behaviour.
Power decides who fits the alarm. A sealed ten-year lithium cell is the DIY pattern: screw it to the ceiling and you do not swap a PP3 each year. Scottish guidance does not accept a user-replaceable PP3 as the battery-only option. A 230 V head with a backup battery is an electrician’s job. In this set that is the BLACK+DECKER BD/MHE/FF, with a 9 V alkaline backup, and the Kidde 4899, also on 230 V with a 9 V backup.
Three typical situations, each with a recommendation from this comparison.
You want one sealed kitchen heat alarm beside smoke alarms you already have. The listing prints BS 5446-2:2003 and KM 694292, at about £11.97, with 4.6 from 898 reviews. It does not claim interlink, and the warranty line is five years against a 10-year battery claim.
A Scottish home or a Northern Ireland private tenancy needs the kitchen heat alarm to sound with the others. This sealed head claims a Kitemark to BS 5446-2:2003 and radio link to up to 20 BLACK+DECKER CONNECTED alarms. The amazon.co.uk line is 3.8 from four reviews, so the interlink claim is on the listing, not on a large sample.
You are swapping an expired Kidde 230 V head and you have checked the connector against the old base. Model 4899 is BSI to BS 5446-2:2003, about £32.91, with 4.6 from 492 reviews and a 9 V backup. Reviews include a connector that did not fit a 123/9HI.
The top pick is the FireAngel FA6720-R. It scores 96 because the listing prints BS 5446-2:2003 and KM 694292, the shelf price is about £11.97, and the amazon.co.uk line is 4.6 from 898 reviews. The five-year warranty against a 10-year cell stays a limit, and it does not claim interlink. The best value is the X-Sense XH02 at about £15.29, score 77, with 4.8 from 202 reviews. It costs less and scores higher than the WISUALARM at about £17.99. It is not cheaper than the FireAngel, and it does not print BS 5446-2.
X-Sense XH02
Best value in the £15 to £18 band at about £15.29, score 77, 4.8 from 202 reviews, with no BS 5446-2 line.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources and the amazon.co.uk listing lines saved on 19 October 2026. No laboratory test.
This page contains affiliate links to amazon.co.uk. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars, and review counts are the UK listing lines. We did not run a lab test.
