Heat pumps · Error codes · ES Heat Pumps AB
F03ES Heat Pumps AB · Energy Save / ES Heat Pumps AB es m r290
F03 on an ES Heat Pumps AB Energy Save / ES Heat Pumps AB es m r290: Compressor discharge temp. sensor failure - Td
Short answer
On an ES Heat Pumps AB heat pump, F03 means: Compressor discharge temp. sensor failure - Td. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: Compressor discharge temp. sensor failure - Td.
Part involved: temperature sensor.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
Resetting itself: unknown.
What you can check
- Note the code shown on the controller and the model number on the rating label before contacting your installer.
- Check that the heat pump isolator / consumer-unit breaker is on; do not open any casing.
- A single restart via the controller (off/on) may be tried only if the manual or your installer allows it.
What the engineer will check
- Follow the manufacturer's troubleshooting steps for this code.
- Check the relevant sensor/switch wiring and connectors.
- Measure/replace the component or PCB as indicated.
Who to ask for: heating / hydraulic.
What you might notice
Sources
- User Guide Air/Water Heat Pump R290 Series ES 100L ST / ES 100L ST UK ↗ · page 23 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026