Heat pumps · Error codes · Danfoss
18Danfoss · DHP-AT
18 on a Danfoss DHP-AT: Frost protection, step 2 (non-fault)
Short answer
On a Danfoss heat pump, 18 means: Frost protection, step 2 (non-fault). The heat pump keeps running.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Frost protection, step 2 (non-fault).
Part involved: Frost protection, step 2 (non-fault).
Is it safe?
| Does the heat pump stop? | No |
|---|---|
| Severity | Information only |
| Engineer needed? | No |
The heat pump keeps running.
What you can check
- Note the 2-digit code. Check the outdoor unit is not blocked by snow, ice, leaves or debris and that airflow around it is clear. If the code persists, call an engineer.
What the engineer will check
- Measure sensor/cable resistance or check the indicated circuit; consult VMGFI302 section 4.4 check and safety functions.
Who to ask for: heat pump engineer.
What you might notice
Sources
- Installation Guide DHP-AT - Installation and service manual (VMGFI302 / AN089486453198) ↗ · VMGFI302 · page p.32 (section 10.1.1); safety functions pp.16-17 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026