Powermax
Powermax Electronic Programmer Unit P458
Electronic programmer unit for Powermax 135, 140 and 155 series gas boilers, used to set heating and hot water times.
At a glance
£214.80
£179.00 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 Powermax P458 is an electronic programmer unit used on Powermax 135, 140 and 155 series gas boilers. It provides the time and temperature control interface for the appliance, allowing heating and hot water periods to be set and the boiler to be switched on and off at the programmed times. The unit is listed against the Horstmann 626 programmer reference.
Signs this part needs replacing
- The display is blank, faded or showing incomplete segments
- Buttons do not respond when setting times or temperatures
- The clock loses time or resets after a power interruption
- The boiler does not switch on or off at the programmed times
- Heating or hot water fails to run during scheduled periods
Before you order
- Confirm the boiler model and GC number against the fitment list
- Check the programmer reference on the existing unit before ordering
- Isolate the electrical supply to the boiler before removing the old programmer
- Inspect the plug, loom and connector for damage before fitting the replacement
Compliance
| GC number | 378-796 |
|---|
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| BAXI Powermax 140 | — | — | — | |
| BAXI Powermax 155X | — | — | — | |
| POWERMAX 135 | 41-389-01 | 41-389-01 | — | — |
| POWERMAX 140 FOV | 41-389-09 | 41-389-09 | — | — |
| POWERMAX 140 FSS | 41-389-10 | 41-389-10 | — | — |
| POWERMAX 155 CP FOV C/W PUMP & CLOCK | 41-389-08 | 41-389-08 | — | — |
| POWERMAX 155 CP SS | 41-389-05 | 41-389-05 | — | — |
| POWERMAX 155 FOV STD MODEL | 41-389-06 | 41-389-06 | — | — |
| POWERMAX 155 P FOV C/W PUMP | 41-389-07 | 41-389-07 | — | — |
| POWERMAX 155 P SS | 41-389-04 | 41-389-04 | — | — |
Showing 10 of 24 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.
POWERMAX appliance manual — 135 (GC 41-389-01)
manualmanualPOWERMAX appliance manual — 140 FOV (GC 41-389-09), 140 FSS (GC 41-389-10)
manualmanualPOWERMAX appliance manual — 155 CP FOV C/W PUMP & CLOCK (GC 41-389-08), 155 CP SS (GC 41-389-05), 155 FOV STD MODEL (GC 41-389-06), 155 P FOV C/W PUMP (GC 41-389-07), 155 P SS (GC 41-389-04), 155 SS (GC 41-389-03), 155X FOV (GC 41-389-14), 155X FSS (GC 41-389-13)
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