E198 on a Samsung heat pump: Error of Terminal Block's Thermal Fuse(Open)
Short answer
On a Samsung heat pump, E198 means: Error of Terminal Block's Thermal Fuse(Open). 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: Error of Terminal Block's Thermal Fuse(Open).
Part involved: Terminal block thermal fuse.
When it shows: Unit self-diagnosis: Error of Terminal Block's Thermal Fuse(Open).
Likely causes:
- Thermal fuse on the terminal block has opened, typically from overheating at connections.
- Engineer checks per Samsung service manual: Terminal block thermal fuse open: inspect terminal block for overheating/loose connections and replace the fuse/terminal block.
Is it safe?
Switch the heat pump off at its isolator and call an engineer.
| 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.
Resetting itself: no.
Manual reset: yes - fuse/terminal block replacement by engineer.
What you can check
- Note the full error code shown on the controller; check the heat pump breaker/isolator in the consumer unit is ON; if there is any burning smell leave the unit switched off; then contact your installer or Samsung service; Samsung manuals do not describe a homeowner reset for this code.
What the engineer will check
- Terminal block thermal fuse open: inspect terminal block for overheating/loose connections and replace the fuse/terminal block. Any work inside casings, on PCBs, wiring, sensors, pumps, valves or refrigerant is engineer-only.
Who to ask for: Heat pump engineer with electrical competence.
Certification: Competent electrical worker (BS 7671).
What you might notice
Sources
- Air to Water Heat Pump User manual AE200DN**** / AE160DN**** / MIM-E03FN (2024 ClimateHub / control kit) DB68-12922A-05 ↗ · DB68-12922A-05 · page p.55 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026