Heat pumps · Error codes · Danfoss
brineflow-lowDanfoss · DHP-H
brineflow-low on a Danfoss DHP-H: Flow sensor not active during last start. Compressor stopped. No hot water production
Short answer
On a Danfoss heat pump, brineflow-low means: Flow sensor not active during last start. Compressor stopped. No hot water production. 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: Flow sensor not active during last start. Compressor stopped. No hot water production.
Part involved: flow switch.
Likely causes:
- Wrong system selected in SYSTEM menu (flow sensor configured but not fitted); insufficient flow - groundwater pump not running, flow switch set/calibrated wrongly, blocked exchanger.
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.
Manual reset: Set operating mode OFF then back to the desired mode.
What you can check
- Note the exact alarm text. The manual allows acknowledging by setting the operating mode to OFF and then back to the previous mode - do this once; if the alarm returns, leave it and call an engineer.
What the engineer will check
- Check SYSTEM menu selection; confirm groundwater pump runs with brine pump; check flow switch wiring and working range; clean/replace intermediate heat exchanger.
Who to ask for: heat pump engineer.
What you might notice
Sources
- Service instructions DHP-A, DHP-A Opti, DHP-AL, DHP-AL Opti, DHP-C, DHP-H, DHP-H Opti, DHP-H Opti Pro, DHP-L, DHP-L Opti, DHP-L Opti Pro (VMGFC302) ↗ · VMGFC302 (© 2010; PDF regenerated 2024-07-10 on assets.danfoss.com) · page printed p.35, p.44 (Table 20); PDF pp.37, 46 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026