Johnson & Starley
Johnson & Starley Main Injector BOS01204/5
Main injector for Johnson & Starley JA33/43 and JAH series warm air units.
At a glance
- Also known as 1690245
£15.66
£13.05 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 main injector is a Johnson & Starley component for JA33/43 and JAH series warm air units. It is listed for use across a range of warm air unit and Janus water heater variants. The part is identified by SKU BOS01204/5.
Signs this part needs replacing
- Persistent ignition failure or lockout
- Weak, yellow, or unstable burner flame
- Sooting or discolouration around the burner area
- Poor combustion or repeated flame supervision faults
- Visible damage, blockage, or wear at the injector
Before you order
- Confirm your appliance model is listed in the Fits section.
- Check the part number BOS01204/5 against the component being removed.
- Inspect the existing injector for damage or blockage before ordering.
- If unsure, check the manufacturer's parts list for your appliance.
Compliance
| GC number | 398-389 |
|---|---|
| Alternative numbers | 1690245 |
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| JOHNSON & STARLEY JA33-43 MAF VI WARM AIR UNIT | 42-417-18 | 42-417-18 | — | — |
| JOHNSON & STARLEY JA33-43 MAF WARM AIR UNIT | 42-417-17 | 42-417-17 | — | — |
| JOHNSON & STARLEY JA33-43 WARM AIR UNIT | 42-417-06 | 42-417-06 | — | — |
| JOHNSON & STARLEY JA33-43 WARM AIR UNIT - JANUS WATER HEATER | 43-416-35 | 43-416-35 | — | — |
| JOHNSON & STARLEY JA33-43-MAF VI WARM AIR UNIT - JANUS WATER HEATER | 43-416-37 | 43-416-37 | — | — |
| JOHNSON & STARLEY JA33-43-MAF WARM AIR UNIT - JANUS WATER HEATER | 43-416-36 | 43-416-36 | — | — |
| JOHNSON & STARLEY JA33-43R MAF VI WARM AIR UNIT | 42-417-21 | 42-417-21 | — | — |
| JOHNSON & STARLEY JA33-43R MAF VI WARM AIR UNIT - JANUS WATER HEATER | 43-416-40 | 43-416-40 | — | — |
| JOHNSON & STARLEY JA33-43R MAF WARM AIR UNIT | 42-417-20 | 42-417-20 | — | — |
| JOHNSON & STARLEY JA33-43R MAF WARM AIR UNIT - JANUS WATER HEATER | 43-416-39 | 43-416-39 | — | — |
Showing 10 of 25 compatible appliances.
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.
JOHNSON & STARLEY appliance manual — JA33-43 MAF VI WARM AIR UNIT (GC 42-417-18), JA33-43 MAF WARM AIR UNIT (GC 42-417-17), JA33-43 WARM AIR UNIT (GC 42-417-06), JA33-43 WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-35), JA33-43-MAF VI WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-37), JA33-43-MAF WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-36)
manualmanualJOHNSON & STARLEY appliance manual — JA33-43R MAF VI WARM AIR UNIT (GC 42-417-21), JA33-43R MAF VI WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-40), JA33-43R MAF WARM AIR UNIT (GC 42-417-20), JA33-43R MAF WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-39), JA33-43R WARM AIR UNIT (GC 42-417-19), JA33-43R WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-38)
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