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Replacement for FireAngel ST-620 10 Year Smoke Alarm - UltraFire ULLS10

4.7 out of 5 stars
£22.43 inc VAT
£18.69 ex VAT
Product Overview

The very popular FireAngel ST-620 10 year optical smoke alarm was discontinued by the manufacturer in 2018. UltraFire have since developed and manufactured an adaptor plate which utilises the existing base plate of the ST-620 and allows an UltraFire ULLS10 optical smoke alarm to be fitted in its place, with no need to drill any further holes in your ceiling.

The UltraFire ULLS10 is powered by a sealed 10 year battery that will not need replacing for the full lifespan of the alarm, and will activate automatically when installed. The adaptor plate simply twists onto your existing ST-620 base plate and provides an ideal and quick solution for the replacement of this alarm. Like the FireAngel ST-620, the UltraFire ULLS10 optical smoke alarm features an end of life warning which can be silenced for up to 10 hours should it occur during the night, and for additional peace of mind it is backed with a 10 year manufacturer's warranty.

  • 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
  • Includes UltraFire Adaptor Plate designed to easily replace old FireAngel ST-620 alarms with the UltraFire ULLS10
    • Removes the requirement to drill additional holes or redecorate when replacing alarms
    • Fits onto existing FireAngel ST-620 base plates
    • Simple twist-on installation
  • Automatic activation and deactivation when attached and removed from the base plate
  • 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 and UKCA marked
  • Kitemarked to BS EN 14604: 2005

Please Note: The UFFASTAP adaptor plate is used for mounting the ULLS10 smoke alarm to an existing FireAngel ST-620 base plate – do not use the standard base plate included in the box with the ULLS10 smoke alarm as well. The standard base plate is only intended for use on its own to directly mount an ULLS10 to the ceiling


This adaptor plate has been designed for use with an UltraFire 10 year alarm in order to help customers replace popular, discontinued FireAngel alarms as easily as possible. By utilising this adaptor plate and the existing base plate on your ceiling, there is no need for any tools, for drilling new holes, or to cover up marks from the previous installation.

In order to replace your old FireAngel alarm, please follow these steps:

  1. Rotate the old FireAngel alarm anti-clockwise to remove it from the base plate
  2. Remove your new UltraFire alarm from the box and discard the standard base plate supplied with it
  3. Rotate the UltraFire alarm clockwise onto the adaptor plate until you hear a click
  4. Test the UltraFire alarm as per the instruction manual to confirm it is working properly before fitting it to the ceiling
  5. Rotate the UltraFire alarm and adaptor plate clockwise onto the old FireAngel base plate that is still attached to the ceiling
    • The outside edge of the adaptor should travel approximately 3cm
Technical Data
Product Code FAST620
Alternative Product Codes ST-622, ST-622T, ST-622Q, ST-622R, ST620, ST622, ULLS10
Battery Type

10 Year Sealed Lithium



Dimensions (HxDia)

Adaptor Plate: 3.8 x 117mm

ULLS10 Optical Smoke Alarm: 34 x 84mm

Operating Temperature

5°C to 30°C

Relative Humidity

< 85%

Sound Output



10 year manufacturer's warranty

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

£22.43 inc VAT

£18.69 ex VAT

Delivery Options

The following delivery options are available on this product.

Free Economy Delivery

Free of Charge - Orders will be delivered in 5-7 working days with Evri

Standard Delivery

£3.19 inc VAT - Orders will be delivered in 2-3 working days with Evri

Next Working Day Delivery

£6.19 inc VAT - Orders will be delivered the next working day with Evri

For dispatch today order within

Excellent Warranty

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

Customer Reviews

420 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: P M

The alarm worked immediately when tested after installation so I'm assuming it'll work if needed in an emergency!

Published on: 25th June 2024

Rating: 4 / 5 Stars

Reviewed by: K M


Published on: 22nd June 2024

Rating: 5 / 5 Stars

Reviewed by: P B

Efficient service.

Published on: 17th June 2024

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Direct Telephone 01507 464181


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