Johnson & Starley
Johnson & Starley B300-0300005 Heat Exchanger
Heat exchanger for Johnson & Starley Hispec and Jb warm air units.
At a glance
- Also known as 1691659
£590.83
£492.36 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 HEAT EXCHANGER is a Johnson & Starley component supplied under part number B300-0300005. It transfers heat from the combustion gases to the circulating air within the appliance, and is fitted to Johnson & Starley Hispec, Jb and Myson/Thorn warm air units.
Signs this part needs replacing
- Visible cracking, splitting or perforation of the heat exchanger surfaces
- Combustion readings outside the expected range, or a change in flame picture
- Soot or corrosion deposits on the exchanger body or flue ways
- Fumes or combustion products entering the circulating air stream
- Repeated lockouts or shutdowns traced to the exchanger during service
Before you order
- Confirm the part number B300-0300005 matches the component being replaced
- Check the appliance data badge for the model and mark number, and match it against the fit list
- Confirm the appliance is the warm air unit variant listed, not a different Johnson & Starley range
- Check whether the heat exchanger is a gas-safe registered engineer only task before arranging fitting
Compliance
| GC number | 245-036 |
|---|---|
| Alternative numbers | 1691659 |
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| JOHNSON & STARLEY HISPEC 20 WARM AIR UNIT | 42-451-03 | 42-451-03 | — | — |
| JOHNSON & STARLEY HISPEC J20 WARM AIR UNIT | 42-416-06 | 42-416-06 | — | — |
| JOHNSON & STARLEY HISPEC J30 WARM AIR UNIT | 42-416-05 | 42-416-05 | — | — |
| JOHNSON & STARLEY HISPEC M31 WARM AIR UNIT | 42-451-10 | 42-451-10 | — | — |
| JOHNSON & STARLEY JB16-20 WARM AIR UNIT | 42-416-94 | 42-416-94 | — | — |
| JOHNSON & STARLEY JB25-30 MAF WARM AIR UNIT | 42-417-64 | 42-417-64 | — | — |
| JOHNSON & STARLEY JB25-30 WARM AIR UNIT | 42-417-44 | 42-417-44 | — | — |
| JOHNSON & STARLEY JB25PB MK1 WARM AIR UNIT | 42-416-01 | 42-416-01 | — | — |
| JOHNSON & STARLEY JB25PB Mk2 WARM AIR UNIT | 42-416-02 | 42-416-02 | — | — |
| JOHNSON & STARLEY JB25PB Mk3 WARM AIR UNIT | 42-416-03 | 42-416-03 | — | — |
Showing 10 of 15 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 — HISPEC J30 WARM AIR UNIT (GC 42-416-05)
manualmanualJOHNSON & STARLEY appliance manual — HISPEC M31 WARM AIR UNIT (GC 42-451-10)
manualmanualJOHNSON & STARLEY appliance manual — JB16-20 WARM AIR UNIT (GC 42-416-94), JB25-30 MAF WARM AIR UNIT (GC 42-417-64), JB25-30 WARM AIR UNIT (GC 42-417-44)
manualmanualJOHNSON & STARLEY appliance manual — JB25PB MK1 WARM AIR UNIT (GC 42-416-01), JB25PB Mk2 WARM AIR UNIT (GC 42-416-02), JB25PB Mk3 WARM AIR UNIT (GC 42-416-03), JB25PB Mk4 WARM AIR UNIT (GC 42-416-04), JB25PB Mk5 WARM AIR UNIT (GC 42-416-13)
manualNo 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.