F23 on a Dimplex heat pump: DC peak detection - system stopped to protect itself
Short answer
On a Dimplex heat pump, F23 means: DC peak detection - system stopped to protect itself. 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: DC peak detection - system stopped to protect itself.
Part involved: IPM DC peak sensing circuitry.
When it shows: Outdoor DC current above 40.1+/-5.0 A (LA6/9MI) or 44.7+/-5.0 A (LA12/16MI); 7 times.
Likely causes:
- Faulty main refrigerant PCB.
- Faulty compressor.
On the WPM heat pump manager platform (error-code grouping)
The manual says: Compressor load: incorrect direction of rotation, phase failure, compressor start-up too long, compressor operating current undervoltage too high, soft starter overtemperature, incorrect mains frequency.
Part involved: Compressor, soft starter/inverter, supply.
Likely causes:
- Incorrect direction of rotation (phase sequence).
- Phase failure.
- Compressor start-up too long.
- Undervoltage / operating current.
- Soft starter overtemperature.
- Incorrect mains frequency.
Is it safe?
On the LA MI inverter outdoor air-to-water (LA 6/9/12/16 MI)
Switch the heat pump off at its isolator and call an engineer.
| 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)
Switch the heat pump off at its isolator and call an engineer.
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
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)
- 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 refrigerant PCB.
- Check compressor windings.
Who to ask for: refrigeration / heat pump service engineer.
Certification: F-Gas (refrigerant handling) certification for any refrigerant-circuit work.
On the WPM heat pump manager platform (error-code grouping)
- Check rotary field (phase sequence).
- Check supply voltage.
- Check soft starter/inverter.
- Inform after-sales service.
Who to ask for: electrical / heat pump service engineer.
Certification: Electrical competence (Part P / qualified electrician) for work inside control panels.
What you might notice
Sources
- GDHV Help Centre article: i have f23 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 55 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026