Navien Combi Boiler: No water from hot water tap – Navien NCB-H

Updated October 13, 2026 · by Aurora Star Tech Inc.

No water from hot water tap - Navien NCB-H on a Navien combi boiler: Nothing comes out when a hot tap is opened.

Homeowner with a combi boiler problem? Call (647) 657-2977 or book a service call — licensed technicians across Vaughan and the GTA.

Applies to: Navien NCB-H combi boilers: NCB-250/150H, NCB-240/130H, NCB-240/110H, NCB-190/080H, NCB-190/060H

Common causes of no water from hot water tap - navien ncb-h

Closed shut-off valves on the hot or cold lines
Clogged DHW cold inlet filter
Boiler frozen
Active error code

How to fix no water from hot water tap - navien ncb-h: step by step

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).

Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

If the unit shows an error code, look it up: Navien Combi Boiler codes

Models

Navien NCB-H

NCB-190/060H NCB-190/080H NCB-240/110H NCB-240/130H NCB-250/150H

Navien NFC-H

NFC-250/175H NFC-250/200H

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 as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.