E040 on a CTC control system alarm/information platform: Low brine flow: often air in the collector, especially just after installation, or over-long collectors; check brine pump speed and brine filter
Short answer
On a CTC heat pump, E040 means: Low brine flow: often air in the collector, especially just after installation, or over-long collectors; check brine pump speed and brine filter. The heat pump keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Low brine flow: often air in the collector, especially just after installation, or over-long collectors; check brine pump speed and brine filter.
Part involved: brine circuit.
Likely causes:
- Air in collector system (especially after installation).
- Collectors too long.
- Brine pump speed too low.
- Blocked brine filter.
Is it safe?
| 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.
Manual reset: Press "Reset alarm" on the display; a persisting fault must be rectified before it can be reset.
What you can check
- If the manual instruction applies, press "Reset alarm" on the display once and note whether the alarm returns (manual allows reset and re-check).
- Note the alarm code/text, the product model and serial number and contact your installer.
What the engineer will check
- Bleed the brine circuit.
- Check brine pump speed setting and brine filter.
- Check collector length/dimensioning and brine temperatures.
Who to ask for: ground source heat pump.
What you might notice
Sources
- CTC EcoZenith i255 Installation and Maintenance Manual (400V 3N~/230V 1N~/230V 3~) ↗ · 162 505 67-9 CR01164 2026-05-10 · page 80 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026