Heat pumps · Error codes · Warmflow
Heating-circuit-freeze-riskWarmflow · Zeno G-Series ground source heat pump GS08/GS16/GS03
Heating-circuit-freeze-risk on a Warmflow Zeno G-Series ground source heat pump GS08/GS16/GS03: Heating circuit freeze risk
Short answer
On a Warmflow heat pump, Heating-circuit-freeze-risk means: Heating circuit freeze risk. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Heating circuit freeze risk.
Part involved: ambient / water temperature protection logic.
Likely causes:
- The temperature of the unit has dropped too low.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
What you can check
- Note the exact code shown on the controller (a photo helps) and report it to your installer or the manufacturer's service line.
- Check the heat pump's supply breaker/isolator at the consumer unit is on (do not open any casing).
- Check the outdoor unit is not blocked by snow, ice build-up or debris.
- Leave the heat pump powered: frost protection needs a permanent electricity supply.
What the engineer will check
- Ensure the unit can start up and run in freeze protection mode (section 3.4.
- Check for blockages in the heating pipework.
- Check the heating pump is functioning correctly.
Who to ask for: heating / hydraulics.
Certification: Competent heating engineer.
What you might notice
Sources
- Warmflow High Efficiency Variable Speed Ground Source Heat Pumps G-Series GS08 / GS16 - User, Installation & Service Instructions (v6) ↗ · v6 · page 56 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026