Johnson & Starley
Johnson & Starley Thermista-Stat BOS01242
Thermista-Stat thermostat for Johnson & Starley Modairflow warm air units and Aquair appliances.
At a glance
- Part type: thermostat (Thermista-Stat)
- Also known as 1690956
Showing prices
£99.19
£82.66 ex. VAT · VAT at 20%
Available to order · 3 working days
Available to order · 3 working days
Not certain it's the right part? The technical team verifies fitment before dispatch — no charge, and it stops a second trip.Call the technical teamSend a technical question
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
The Thermista-Stat is a thermostat manufactured by Johnson & Starley for use on Modairflow (MAF) warm air units and related Aquair appliances. It controls the appliance's heat output in response to room or unit temperature, cycling the burner to hold the set condition. This version is listed for Lambeth and Modairflow applications only.
Signs this part needs replacing
- The appliance runs continuously and does not shut down when the set temperature is reached
- Room or unit temperature overshoots noticeably before the burner cycles off
- The burner short-cycles or responds erratically to changes in demand
- No change in appliance behaviour when the thermostat setting is adjusted
- The thermostat becomes intermittent, with heat output dropping out and returning without input
Before you order
- Confirm your appliance model against the fit list above, as this thermostat is specified for Modairflow and Lambeth applications only
- Check whether your unit carries the MAF designation, as non-MAF variants use different controls
- Compare the part number on the existing thermostat with BOS01242 before ordering
- Check the appliance's installation and service documentation for the correct control for your build
Compliance
| Barcode / EAN | 5055189909113 |
|---|---|
| Alternative numbers | 1690956 |
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| JOHNSON & STARLEY AQUAIR 40 | — | — | — | |
| JOHNSON & STARLEY AQUAIR 80 | — | — | — | |
| JOHNSON & STARLEY AQUAIR UNIVERSAL | — | — | — | |
| 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 J50 WARM AIR UNIT | 42-451-13 | 42-451-13 | — | — |
| JOHNSON & STARLEY HISPEC J65 WARM AIR UNIT | 42-451-14 | 42-451-14 | — | — |
| JOHNSON & STARLEY HISPEC J90 WARM AIR UNIT | 42-451-15 | 42-451-15 | — | — |
| JOHNSON & STARLEY HISPEC JU55 WARM AIR UNIT PROPANE | 42-416-09 | 42-416-09 | — | — |
Showing 10 of 143 compatible appliances.
Fitment listings are a guide, not a guarantee. Plant-room assemblies get modified on site more often than not. Send us the GC number off the data badge and a photo of the existing valve and we will confirm before anything is dispatched.
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.
manual
JOHNSON & STARLEY appliance manual — AQUAIR 80, AQUAIR UNIVERSAL
manualmanualJOHNSON & STARLEY appliance manual — HISPEC J30 WARM AIR UNIT (GC 42-416-05)
manualmanualJOHNSON & STARLEY appliance manual — HISPEC J50 WARM AIR UNIT (GC 42-451-13)
manualmanualJOHNSON & STARLEY appliance manual — HISPEC J65 WARM AIR UNIT (GC 42-451-14)
manualmanualJOHNSON & STARLEY appliance manual — HISPEC J90 WARM AIR UNIT (GC 42-451-15)
manualmanualJOHNSON & STARLEY appliance manual — HISPEC JU55 WARM AIR UNIT PROPANE (GC 42-416-09), HISPEC JU55 WARM AIR UNIT (GC 42-511-16)
manualmanualJOHNSON & STARLEY appliance manual — J15-22 WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-23), J15-22 MAF WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-25), J15-22 MAF WARM AIR UNIT (GC 42-417-03), J15-22 MK3 WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-27), J15-22 MK3 MAF VI WARM AIR UNIT (GC 42-417-22), J15-22 MK3 MAF VI WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-41), J15-22 MK3 MAF WARM AIR UNIT (GC 42-417-09), J15-22 MK3 WARM AIR UNIT (GC 42-417-07), J15-22 Mk3 WARM AIR UNIT - ELJAN WATER HEATER (GC 43-416-69), J15-22 Mk3 WARM AIR UNIT - HIJAN WATER HEATER (GC 43-416-84), J15-22 Mk3 MAF VI WARM AIR UNIT - ELJAN WATER HEATER (GC 43-416-71), J15-22 Mk3 MAF VI WARM AIR UNIT - HIJAN WATER HEATER (GC 43-416-86), J15-22 WARM AIR UNIT (GC 42-417-01), J25-32 MK3 MAF VI WARM AIR UNIT (GC 42-417-24), J25-32 MK3 MAF VI WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-43), J25-32 MK3 MAF VI WARM AIR UNIT - SUPERJAN WATER HEATER (GC 42-417-82), J25-32 MK3 MAF WARM AIR UNIT (GC 42-417-13), J25-32 MK3 MAF WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-33), J25-32 MK3 MAF WARM AIR UNIT - SUPERJAN WATER HEATER (GC 42-417-81), J25-32 MK3 WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-31), J25-32 MK3 WARM AIR UNIT - SUPERJAN WATER HEATER (GC 42-417-80), J25-32 Mk3 MAF VI WARM AIR UNIT - ELJAN WATER HEATER (GC 43-416-77), J25-32 Mk3 MAF VI WARM AIR UNIT - HIJAN WATER HEATER (GC 43-416-92), J25-32 Mk3 MAF WARM AIR UNIT - ELJAN WATER HEATER (GC 43-416-76), J25-32 Mk3 MAF WARM AIR UNIT - HIJAN WATER HEATER (GC 43-416-91), J25-32 Mk3 WARM AIR UNIT - ELJAN WATER HEATER (GC 43-416-75), J25-32 Mk3 WARM AIR UNIT - HIJAN WATER HEATER (GC 43-416-90), 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 — J15-22R WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-24), J15-22R MAF WARM AIR UNIT (GC 42-417-04), J15-22R MAF WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-26), J15-22R MK3 MAF VI WARM AIR UNIT (GC 42-417-23), J15-22R MK3 MAF WARM AIR UNIT (GC 42-417-10), J15-22R MK3 MAF WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-30), J15-22R MK3 WARM AIR UNIT (GC 42-417-08), J15-22R MK3 WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-28), J15-22R Mk3 WARM AIR UNIT - ELJAN WATER HEATER (GC 43-416-72), J15-22R Mk3 WARM AIR UNIT - HIJAN WATER HEATER (GC 43-416-87), J15-22R Mk3 MAF VI WARM AIR UNIT - ELJAN WATER HEATER (GC 43-416-74), J15-22R Mk3 MAF VI WARM AIR UNIT - HIJAN WATER HEATER (GC 43-416-89), J15-22R WARM AIR UNIT (GC 42-417-02), J25-32R MAF WARM AIR UNIT (GC 42-416-80), J25-32R MAF WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-14), J25-32R MK2 - MAF - JANUS AIR-WATER HEATER (GC 43-416-22), J25-32R MK2 MAF WARM AIR UNIT (GC 42-416-89), J25-32R MK2 WARM AIR UNIT (GC 42-416-85), J25-32R MK2 WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-20), J25-32R MK3 MAF VI WARM AIR UNIT- SUPERJAN WATER HEATER (GC 42-417-85), J25-32R MK3 MAF VI WARM AIR UNIT (GC 42-417-25), J25-32R MK3 MAF VI WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-44), J25-32R MK3 MAF WARM AIR UNIT (GC 42-417-14), J25-32R MK3 MAF WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-34), J25-32R MK3 MAF WARM AIR UNIT - SUPERJAN WATER HEATER (GC 42-417-84), J25-32R MK3 WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-32), J25-32R Mk3 MAF VI WARM AIR UNIT - ELJAN WATER HEATER (GC 43-416-80), J25-32R Mk3 MAF VI WARM AIR UNIT - HIJAN WATER HEATER (GC 43-416-95), J25-32R Mk3 MAF WARM AIR UNIT - ELJAN WATER HEATER (GC 43-416-79), J25-32R Mk3 MAF WARM AIR UNIT - HIJAN WATER HEATER (GC 43-416-94), J25-32R Mk3 WARM AIR UNIT - ELJAN WATER HEATER (GC 43-416-78), J25-32R Mk3 WARM AIR UNIT - HIJAN WATER HEATER (GC 43-416-93), J25-32R WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-08), 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)
manualmanualJOHNSON & STARLEY appliance manual — J25-32 MAF WARM AIR UNIT (GC 42-416-79), J25-32 MAF WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-13), J25-32 MK2 MAF WARM AIR UNIT (GC 42-416-88), J25-32 MK2 MAF WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-21), J25-32 MK2 WARM AIR UNIT (GC 42-417-11), J25-32 MK2 WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-19), J54-64 MAF VI WARM AIR UNIT (GC 42-417-28), J54-64 MAF VI WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-47), J54-64 MAF WARM AIR UNIT - JANUS WATER HEATER (GC 43-416-16), J54-64 WARM AIR UNIT (GC 42-416-70), J55-65 WARM AIR UNIT (GC 42-417-68), 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), JB40-50 WARM AIR UNIT (GC 42-417-65), JT19-25 MK1 WARM AIR UNIT (GC 42-416-78), Q44
manualmanualJOHNSON & STARLEY appliance manual — J54-64 MAF WARM AIR UNIT (GC 42-416-82)
manualmanualJOHNSON & STARLEY appliance manual — J70-90 MK2 MAF WARM AIR UNIT (GC 42-417-71), J70-90 MK2 WARM AIR UNIT (GC 42-417-70)
manualmanualJOHNSON & STARLEY appliance manual — JT19-25 Mk2 MAF WARM AIR UNIT - ELJAN WATER HEATER, JT19-25 Mk2 WARM AIR UNIT (GC 42-417-38)
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