By clicking a retailer link you consent to third party cookies that track your onward journey. If you make a purchase, Which? will receive an affiliate commission which supports our mission to be the UK's consumer champion.

FireAngelST-750 10 year Thermoptek Smoke Alarm

Smoke alarm
Battery only
Optical smoke alarm

£17.98View retailers

Test score

Lowest available price

£17.98Amazon Marketplace UK

Sign up to unlock the full expert review

The FireAngel ST-750 10 year Thermoptek smoke alarm comes with a sealed and tamper-proof battery that will give you a decade’s worth of smoke detection. FireAngel tell us that the ST-750’s thermally enhanced optical sensor allows it to detect fires quickly. To put this to the test, we tested it at our lab. Check our verdict, fire test results and the total test score for this FireAngel smoke alarm to see whether it’s one to consider or one to be left on the shelf.

pros

Content has been blurred out, please log in to view.

cons

Full Access first month £5, then £10.99 per month, cancel at any time

KEY TEST RESULTS
Wood fires
Cotton fires
Sound output

Oct 2023Last checked by Which?
Aug 2018First reviewed by Which?
Jul 2017Released

The overall Which? test score is made up of the following star ratings, all determined by our rigorous lab tests.

How we test smoke alarms and heat alarms

27 Feb 2024

Wood fires

How we test wood fires

We measure the amount and thickness of wood smoke from a smouldering fire that is required to trigger the alarm. This test isn't carried out for heat alarms, which are tested to a different programme. Only applicable to smoke alarms.

Cotton fires

How we test cotton fires

We measure the amount and thickness of cotton smoke from a smouldering fire that is required to trigger the alarm. This test isn't carried out for heat alarms, which are tested to a different programme. Only applicable to smoke alarms.

Plastics fires

How we test plastics fires

We measure the amount and thickness of smoke from a plastics fire that is required to trigger the alarm. This test isn't carried out for heat alarms, which are tested to a different programme. Only applicable to smoke alarms.

Solvent fires

How we test solvent fires

We measure the amount and thickness of smoke from a solvents fire that's required to trigger the alarm. This test isn't carried out for heat alarms, which are tested to a different programme. Only applicable to smoke alarms.

Sound output

How we test sound output

Sound output is based on decibel levels, measured in a fully soundproofed chamber. Three stars or above are louder than 85dB – the equivalent of a lawn mower. Ones rated two stars or below should probably be avoided by those with poor hearing. This test isn't carried out for heat alarms, which are tested to a different programme. Only applicable to smoke alarms.

Sensitivity

How we test sensitivity

We test alarms with smoke from burning toast and steam from a shower head to see if they can tell the difference between normal household activity and a real fire. This test isn't carried out for heat alarms, which are tested to a different programme. Only applicable to smoke alarms.

Ease of use

How we test ease of use

Ease of use includes clarity of instructions including installation and maintenance, how simple it is to insert and replace the battery, use the hush button and any interconnectivity features. This test isn't carried out for heat alarms, which are tested to a different programme. Only applicable to smoke alarms.

General
Type	Smoke alarm
Power source	Battery only
Technology	Optical smoke alarm
10-year battery	Yes
Wood fire response time (Smoke alarms only)
Cotton fire response time (Smoke alarms only)
Plastics fire response time (Smoke alarms only)
Solvent fire response time (Smoke alarms only)

Features
Light	No
Hush button	Yes

Compare retailers

Prices updated daily

Prices are ordered from lowest to highest, irrespective of retailer rating or stock, and exclude any potential delivery costs. We are not able to show every possible retailer and cheaper prices may be available.

Amazon Marketplace UK
In Stock£17.98

Suggested Alternatives

FireAngel

SW1-R

Smoke alarm
Mains only
Optical smoke alarm

£18.74View retailers

Test score

Nest

Protect 2nd Generation Smoke + Carbon Monoxide Alarm

Smoke alarm
Battery/Mains
Smart optical smoke alarm

£94.99View retailers

Test score

FireAngel

SB1-R

Smoke alarm
Battery only
Optical smoke alarm

£8.20View retailers

Test score

How to place and maintain smoke alarms
Buying a smoke alarm isn't enough when it comes to fire safety – you need to buy the right one for your home and position it correctly. Find out how.
How we test smoke alarms and heat alarms
To uncover the Best Buy smoke alarms that you can trust, we put every smoke alarm we review to the test against four different types of fire. And for heat alarms - which detect rapid temperature rises - we run five heat detection tests to check how well they work.
Best smoke alarms
Which smoke alarm should you buy - ionisation, optical or heat alarm? Find out how to choose the best smoke alarm for your home.

All smoke alarm advice

FireAngelST-750 10 year Thermoptek Smoke Alarm

Lowest available price

Sign up to unlock the full expert review

pros

cons

How we test smoke alarms and heat alarms

Wood fires

Cotton fires

Plastics fires

Solvent fires

Sound output

Sensitivity

Ease of use

Compare retailers

How this product's score compares with other smoke alarms we've tested

Suggested Alternatives

FireAngel

Nest

FireAngel

Related articles

FireAngelST-750 10 year Thermoptek Smoke Alarm

Lowest available price

pros

cons

Test results

Specifications

Where to buy (1 retailer)

Best Buys & Don't Buys

Suggested Alternatives

FireAngel

Nest

FireAngel

Related articles