HVACopediaNavien · Combi boiler troubleshooting
No water from hot water tap - Navien NCB-H
What is going on
Nothing comes out when a hot tap is opened.
Likely causes
- Closed shut-off valves on the hot or cold lines
- Clogged DHW cold inlet filter
- Boiler frozen
- Active error code
Check in this order
- Make sure the shut-off valves on the hot and cold pipes at the boiler are open.
- Clean the DHW cold water inlet filter.
- Look for an error code on the front panel and look it up.
- If the unit may be frozen, do not run it - thaw and inspect for damage (freeze damage is not covered by warranty).
Applies to: Navien NCB-H combi boilers: NCB-250/150H, NCB-240/130H, NCB-240/110H, NCB-190/080H, NCB-190/060H
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Source: Navien NCB-H User's Information Manual Version 1.0 (April 2024), 5.1 Solving Basic Problems, p.24. Written in our own words; check the manual for your exact model.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.