Navien Error Code Space heating demand icon: Space heating demand (Combi Boiler)

Updated October 15, 2026 · by Aurora Star Tech Inc.

Navien error code Space heating demand icon on a combi boiler means: Space heating demand. It is also called Navien diagnostic code Space heating demand icon.

Low severityCombi BoilerNavien NCB-H

Homeowner? What Navien code Space heating demand icon means for you

Usually minor Your combi boiler is reporting: Space heating demand. This code is usually informational or minor. The safe checks below often clear it; call us if it keeps showing up.

Safe things you can check yourself

Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
Look at the pressure gauge on the boiler. If it reads much lower than usual or near zero, or water is leaking, call a technician.
Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
Check that the boiler gas valve is open (handle in line with the pipe).
Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.
If only hot water is missing, check that the hot water tap is open far enough to start the heater.

Call (647) 657-2977 Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Navien error code Space heating demand icon mean?

Indicates space heating calls from thermostats 1, 2 and 3.

Applies to: NCB-190/060H to NCB-250/150H

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.

Navien models that use code Space heating demand icon

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

Other Navien Combi Boiler codes

Code	Meaning
Outdoor temperature	Outdoor temperature display
Outlet2 Temp	Status Information item 10 - Outlet2 Temp
Outlet Temp	Status Information item 11 - Outlet Temp
Panel F/W Ver	Status Information item 33 - Panel F/W Ver
Return Temp	Status Information item 7 - Return Temp
SH Set Temp	Status Information item 3 - SH Set Temp
Space heating set temperature	Space heating set temperature display
Status Information	Status Information menu
Supply Temp	Status Information item 6 - Supply Temp
Sys Return Temp	Status Information item 9 - Sys Return Temp
Sys Supply Temp	Status Information item 8 - Sys Supply Temp
System check icon	System check or error needed

All Navien Combi Boiler error codes →

Navien code Space heating demand icon: homeowner questions

What does Navien code Space heating demand icon mean?

Space heating demand. Indicates space heating calls from thermostats 1, 2 and 3.

Is it safe to keep using my combi boiler with code Space heating demand icon?

Usually yes. Code Space heating demand icon is normally minor, but if it keeps coming back have it checked.

Can I reset Navien code Space heating demand icon myself?

You can try one reset (power off for 30 seconds, then on). If Navien code Space heating demand icon comes back, the cause is still there and a licensed technician should check it.

Who can fix Navien code Space heating demand icon near me?

Aurora Star Tech Inc. repairs Navien combi boilers in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: Tankless Water Heater No Hot Water: What to Check · Boiler Not Heating: What to Check

Troubleshooting guides

Change gas type with DIP switch 2 Navien · Combi Boiler
Change installer parameters (password 1234) Navien · Combi Boiler
Force a fixed firing rate with DIP switch 1 Navien · Combi Boiler
Force minimum or maximum firing (special operations) Navien · Combi Boiler
Hot water is cold or turns cold - Navien NCB-H Navien · Combi Boiler
Hot water not hot enough or too hot - Navien NCB-H Navien · Combi Boiler
No space heating - Navien NCB-H Navien · Combi Boiler
No water from hot water tap - Navien NCB-H Navien · Combi Boiler
Open the service / installer menu (Back + Menu) Navien · Combi Boiler
Purge air from the heating piping (Air Purge Mode) Navien · Combi Boiler
Read live data (Status Information menu) Navien · Combi Boiler
Read the error history Navien · Combi Boiler
Reset one parameter to its default Navien · Combi Boiler
Run test mode (fan, pumps, valves, venturi) Navien · Combi Boiler
Set the altitude with DIP switch 2 Navien · Combi Boiler

Source: Navien NCB-H User's Information Manual (V1.0 Apr 2024), 2.3.1 Icons and Digital Display, p.8. 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.