Johnson & Starley
Johnson & Starley Combined Sensor Assembly SCS 25MAF
Combined air flow sensor and limit thermostat assembly for Johnson & Starley SCS 25 boilers.
At a glance
- Also known as 1690965
£97.12
£80.93 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 SCS 25MAF is a combined air flow sensor and limit thermostat assembly manufactured by Johnson & Starley. It monitors air flow through the appliance and provides overheat protection by interrupting the burner sequence when the limit is exceeded. It is used on the Johnson & Starley SCS 25 boiler range.
Signs this part needs replacing
- The boiler locks out or fails to fire despite the fan running
- Repeated lockouts that clear on reset but return shortly after
- Intermittent shutdowns during a demand for heat
- The limit stat trips before the appliance reaches temperature
- Inconsistent or absent air flow sensing during the ignition sequence
Before you order
- Confirm the appliance model is an SCS 25 and check the GC number against your data badge
- Compare the markings and part reference on the existing sensor with SCS 25MAF
- Check whether your appliance is the Mk1 variant before ordering
Compliance
| Alternative numbers | 1690965 |
|---|
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| JOHNSON & STARLEY JOHNSON AND STARLEY SCS 25 | — | — | — | |
| JOHNSON & STARLEY SCS25 MK1 | 42-417-93 | 42-417-93 | — | — |
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.
Not sure which part?
Search by part number, product name or brand — our technical team confirms fitment before anything is dispatched.