CH232 on a LG heat pump: Problem in water flow sensor – flow sensor damaged or incorrectly connected
Short answer
On a LG heat pump, CH232 means: Problem in water flow sensor – flow sensor damaged or incorrectly connected. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Problem in water flow sensor – flow sensor damaged or incorrectly connected.
Part involved: water flow sensor (CN_F_SENSOR).
When it shows: Flow sensor voltage abnormal (normal 1.22 V at 23 LPM; 0.5-3.5 V for 5-80 l/min; 5 V supply).
Likely causes:
- Incorrect connection between sensor and PCB; PCB fault; sensor fault; cable interference.
Is it safe?
| 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: no.
Manual reset: Service-engineer repair and restart required (LG: resumed only after certificated professional's check).
What you can check
- Read the code on the controller (LG shows 'CH' + number; older wired controllers alternate 'CH' and the number) and note it together with the model number. Report it to your installer or an LG-authorised service centre – LG owner's manuals say an error code generated by self-diagnosis is a reason to call the service. This is an 'Error'-class fault: LG says the system can only be resumed after a qualified professional has checked it, so do not keep trying to restart it.
What the engineer will check
- Check connector and cable routing, 5 V supply and signal voltage against the flow table; replace flow sensor then PCB.
Who to ask for: Heat pump engineer (controls, sensors, PCB).
Certification: None statutory beyond electrical competence (BS 7671).
What you might notice
Sources
- AIR-TO-WATER HEAT PUMP SERVICE MANUAL (General) – R32 Hydrosplit, MFL68682007 ↗ · MFL68682007 · page 71, 77-79 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026