Navien Combi Boiler: Hot water not hot enough or too hot – Navien NCB-H

Hot water not hot enough or too hot - Navien NCB-H on a Navien combi boiler: DHW temperature at the taps is lower or higher than wanted.

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 hot water not hot enough or too hot - navien ncb-h

• DHW set temperature too low or too high
• Cross piping between heating supply and return lines
• Flow above the unit's capacity for the temperature rise

How to fix hot water not hot enough or too hot - navien ncb-h: step by step

1. Check the DHW set temperature (range 86-140°F, default 122°F).
2. WARNING: water above 120°F can scald instantly.
3. Water too cool? Look for a cross-connection between the heating supply and return piping.
4. Compare the flow with the rated DHW flow at the needed temperature rise for the model.

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

Models

Navien NCB-H

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

Navien NFC-H

NFC-250/175HNFC-250/200H