Horstmann Controls
Secure SIR021 E30 immersion boost timer
A push-button 30/60/120-minute boost timer from Secure (Horstmann) for immersion heaters, towel rails and other resistive loads up to 3kW.
At a glance
- Also known as 4210173
£48.25
£40.21 ex. VAT · VAT at 20%
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
The SIR021 is a digital boost timer manufactured by Secure Meters (trading under the Horstmann brand in this listing, also known as the Electrisaver E30). Pushing the button cycles through 30, 60 or 120-minute boost periods, shown by LED indicators, and the connected load switches off automatically at the end of the period or can be switched off manually.
Signs this part needs replacing
- Timer fails to start a boost cycle when pressed
- LED indicators not lighting or stuck on
- Load does not switch off at the end of the set period
- Casing cracked or button unresponsive
Before you order
- Confirm your load is within the 3kW resistive rating before fitting
- Isolate the electricity supply before removing the old timer
- Wiring work should be carried out by a competent, qualified electrician
Compliance
| Alternative numbers | 4210173 |
|---|
No fitment data held for this part.
Documents & drawings
Everything we hold for this part. Where a document exists but we don't hold it, the technical team will source it from the manufacturer — usually the same working day.
No documents held for this part. The technical team will source them from the manufacturer — usually the same working day.
No technical questions yet for this part.
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Tell the parts assistant what it's going into — the appliance make and model, or the GC number off the data badge — and it will check this part is on the fit list.