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Replacement for FireAngel ST-620 10 Year Smoke Alarm

4.7 out of 5 stars
£18.90 inc VAT
£15.75 ex VAT
Product Overview

The very popular FireAngel ST-620 10 year optical smoke alarm was discontinued by the manufacturer in 2018. Firehawk have since developed and manufactured an adaptor plate which utilises the existing base plate of the ST-620 and allows a Firehawk FHB10 optical smoke alarm to be fitted in its place, with no need to drill any further holes in your ceiling.

The Firehawk FHB10 optical smoke alarm features a 10 year sealed lithium battery and a large test and silence button to make weekly testing easy. Improved smoke detection is provided through the use of Thermal Stability Enhancement Technology (TSE), and the X-Profile detection sensor chamber has been designed specifically to reduce false alarms.

  • FREE delivery
  • Optical smoke sensor suitable for installations in hallways, landings, living areas and bedrooms
  • Battery: 10 year sealed lithium battery
  • Warranty: 10 year manufacturer's warranty
  • Supplied with adapter plate and FHB10 optical smoke alarm from Firehawk
  • Adapter plate fits directly onto existing ST-620 base plate
  • Automatic activation and deactivation when attached and removed from the base plate
  • X-Profile detection chamber specifically designed to reduce false alarms
  • TSE (Thermal Stability Enhancement) Technology provides improved smoke detection
  • Combined test and silence button, almost the whole face of the alarm
  • Low battery warning chirps can be silenced up to 10 hours
  • Suitable for installations complying to BS 5839-6: 2019 Grade F1
  • CE marked and Kitmarked to BS EN 14604: 2005

Please Note: The FHSAP adaptor plate is used for mounting the FHB10 smoke alarm to an existing FireAngel ST-620 base plate – do not use the standard base plate included in the box with the FHB10 smoke alarm as well. The standard base plate is only intended for use on its own to directly mount an FHB10 to the ceiling.

Technical Data
Product Code FAST620
Alternative Product Codes ST-622, ST-622T, ST-622Q, ST-622R, ST620, ST622
Brand Firehawk
Battery Type

10 Year Sealed Lithium

Dimensions (HxDia)

Adaptor Plate: 3.8 x 117mm

FHB10 Optical Smoke Alarm: 34 x 84mm

Operating Temperature

5°C to 30°C

Relative Humidity

< 85%

Sound Output



10 Years

Weight 0.21kg
Product Datasheets
FAQs (2)
Q. Can a smoke alarm be fitted with a sticky adhesive pad in a let property?

The sticky pad is suitable for all battery operated smoke alarms. However, we cannot judge if battery alarms are suitable for your let property, as let properties usually require mains powered alarms. There is some advice to this in the governments guides to fire risk assessments. Also see the LACoRS guide for let properties.

Q. What sort of smoke alarm system would I need to install for a HMO?

BS 5839-6 recommends that one or two storey HMOs with an individual floor area of no more than 200sqm (not the total of both floors) should have a Grade D smoke alarm system installed. Grade D refers to mains powered smoke alarms with a back up battery power supply. The alarms can be interlinked either by wire or by radio signal and the system does not require a separate fire alarm panel. For HMOs of 3 storey or higher, a Grade A panel system would need to be installed. This can cover the whole of the building, or can be used just for the communal areas with a separate Grade D system installed for the individual dwellings. For both applications, the level of cover should be a minimum of LD3 (in all escape routes) but this may change according to the fire risk assessment.

Pricing & Availability

Model Stock Price
Product Code: FAST620 Stock Level:
More than 20 in stock Expected dispatch: Today

£18.90 inc VAT

£15.75 ex VAT

Delivery Options

The following delivery options are available on this product.

Free Economy Delivery

Free of Charge - Orders will be delivered in 3-5 working days with Evri by Hermes

Express Delivery

£8.10 inc VAT - Orders will be delivered in 1-2 working days with Evri by Hermes

Excellent Warranty

This product is supplied with a 10 year manufacturers warranty as standard

Customer Reviews

383 customers have given this product an overall rating of 4.7 out of 5

Reviews by real customers

All of our product reviews are written by real customers that have purchased this product from us and are published without modification.

Rating: 5 / 5 Stars

Reviewed by: S Y

Excellent service at a good price

Published on: 11th June 2022

Rating: 5 / 5 Stars

Reviewed by: A K

Appears fit for purpose but fortunately has not been tested in reality. The fire alarm fitted onto the old base so was easy to fit. Delivery of the alarm was exceptional. Ordered and delivered in under 24 hours. Periodic testing shows it is working. It is not as sensitive as the old one wh8ch is no bad thing as I can now make toast or a bacon sandwich w8thout the alarm going off! ????

Published on: 20th May 2022

Rating: 5 / 5 Stars

Reviewed by: G R

excellent value

Published on: 19th May 2022

Rating: 5 / 5 Stars

Reviewed by: P S

Dream replacement not having to renew base plate. Wish more manufacturers would design modularity into there products

Published on: 16th February 2022

Rating: 5 / 5 Stars

Reviewed by: N H

Exactly the same as the previous one that lasted 12 years

Published on: 8th January 2022

Rating: 5 / 5 Stars

Reviewed by: M C

Quick efficient and helpful. Sorted.

Published on: 19th November 2021

Rating: 5 / 5 Stars

Reviewed by: S D

Excellent company Easy to use site delivery as expected highly recommend company and products

Published on: 9th November 2021

Rating: 5 / 5 Stars

Reviewed by: C A


Published on: 27th May 2021

Rating: 5 / 5 Stars

Reviewed by: C H

no problem with this product and we were able to use the existing fitting, very pleased.

Published on: 9th May 2021

Rating: 4 / 5 Stars

Reviewed by: R S

Replacement Fire angel has worked perfectly Fire Angels require cleaning on a regular basis to prevent the beeping sound. A simple purpose designed motorised cleaner would be useful

Published on: 15th March 2021

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