F15 on a Dimplex heat pump: No rotation detected by the outdoor fan motor(s)
Short answer
On a Dimplex heat pump, F15 means: No rotation detected by the outdoor fan motor(s). The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause. The wording differs by model range — each is shown below.
Reviewed 23 September 2026 · 2 sources
What it means
On the LA MI inverter outdoor air-to-water (LA 6/9/12/16 MI)
The manual says: No rotation detected by the outdoor fan motor(s).
Part involved: Outdoor fan motor (Hall IC).
When it shows: Fan feedback >2550 rpm or <50 rpm; 2 times in 30 minutes.
Likely causes:
- Short circuit in fan motor winding.
- Broken wire in fan motor or leads.
- Fan motor Hall IC malfunction.
- Faulty outdoor PCB.
On the WPM heat pump manager platform (error-code grouping)
The manual says: Sensors: there is a fault with the required sensors; the exact cause is shown in the plain text display.
Part involved: Temperature/pressure sensors (return, flow, DHW, outside, hot gas, HP/LP sensors etc.).
Likely causes:
- Sensor connecting line interrupted.
- Plug loose.
- Lines mixed up.
- Sensor short-circuit or open circuit.
- Wrong coding number (GDHV).
Is it safe?
On the LA MI inverter outdoor air-to-water (LA 6/9/12/16 MI)
| Does the heat pump stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Resetting itself: unknown.
Manual reset: Clear via control panel per Dimplex article (method shown as image).
On the WPM heat pump manager platform (error-code grouping)
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
Resetting itself: After rectifying the fault the heat pump can be restarted; switching off the control voltage also acknowledges the fault (WPM Touch p.54). On text-display WPMs press Esc to acknowledge (EconPlus EN-16).
Manual reset: Acknowledge after rectification.
What you can check
On the LA MI inverter outdoor air-to-water (LA 6/9/12/16 MI)
- Check (without opening the unit) that the fan is not blocked by ice, snow or debris.
- Note the code and contact the installer or Dimplex service.
On the WPM heat pump manager platform (error-code grouping)
- Note the fault code, the heat pump model (type plate) and controller software version shown in operating data, and contact the installer/Dimplex service.
What the engineer will check
On the LA MI inverter outdoor air-to-water (LA 6/9/12/16 MI)
- Isolate the heat pump from mains before any work.
- Check fan motor and leads.
- Replace fan motor X-2511025 / X-2511045/46 or PCB.
Who to ask for: heat pump service engineer / heating engineer.
Certification: Electrical competence (Part P / qualified electrician) for work inside control panels.
On the WPM heat pump manager platform (error-code grouping)
- Read plain-text sensor name.
- Check sensor cable/plug.
- Measure sensor resistance against temperature table.
- Verify WPM coding number against type plate.
Who to ask for: heat pump service engineer.
What you might notice
Sources
- GDHV Help Centre article: i have f15 error on my la mi heat pump what does this mean ↗ · GDHV article (modified 2023-02) · page n/a (web article) · Reviewed 23 September 2026
- Dimplex WPM Touch heat pump manager - Operating instructions for users and specialists (Order no. 452117.66.02-EN, WPM3.13 / Display 1.15) ↗ · 452117.66.02-EN FD 0302 · page 54 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026