KeepRite Error Code Phase monitor LED off: 3-phase monitor – no call for compressor (Heat Pump)

Updated October 16, 2026 · by Aurora Star Tech Inc.

KeepRite error code Phase monitor LED off on a heat pump means: 3-phase monitor - no call for compressor. It is also called KeepRite diagnostic code Phase monitor LED off.

Low severityHeat PumpKeepRite N4H4/R4H4/WCH4/NXH5 Heat Pump

Homeowner? What KeepRite code Phase monitor LED off means for you

Usually minor Your heat pump is reporting: 3-phase monitor - no call for compressor. 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.
Check both breakers and the outdoor disconnect box beside the outdoor unit; all should be ON.
Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
In winter, keep snow and ice off and away from the outdoor unit. A short defrost cycle with steam is normal.
Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.

Call (647) 657-2977 Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does KeepRite error code Phase monitor LED off mean?

The phase monitor LED is dark when there is no call for compressor operation. Nothing is wrong.

Applies to: N4H4/R4H4/WCH4/NXH5 three-phase heat pumps

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.

KeepRite models that use code Phase monitor LED off

N4H4 NXH5 R4H4 R4H449 WCH4

Other KeepRite Heat Pump codes

Code	Meaning
Amber LED on solid	Standby - no call (communicating)
Brown-out defeat toggle	Turn 230 V brown-out protection off or on
Defrost speed-up pins	Speed up the defrost timer for testing
Fan delay defeat toggle	Switch the post-defrost outdoor fan delay off or on
Forced defrost pins	Force a defrost cycle / skip the 5-minute delay
Phase monitor LED flashing	3-phase monitor - phase reversal
Phase monitor LED on	3-phase monitor - phases OK

All KeepRite Heat Pump error codes →

KeepRite code Phase monitor LED off: homeowner questions

What does KeepRite code Phase monitor LED off mean?

3-phase monitor - no call for compressor. The phase monitor LED is dark when there is no call for compressor operation. Nothing is wrong.

Is it safe to keep using my heat pump with code Phase monitor LED off?

Usually yes. Code Phase monitor LED off is normally minor, but if it keeps coming back have it checked.

Can I reset KeepRite code Phase monitor LED off myself?

You can try one reset (power off for 30 seconds, then on). If KeepRite code Phase monitor LED off comes back, the cause is still there and a licensed technician should check it.

Who can fix KeepRite code Phase monitor LED off near me?

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

Homeowner help: AC Running But Not Cooling: What to Check · Heat Pump Not Heating or Blowing Cold Air

Troubleshooting guides

2 flashes: HPS open ≥6 s; 3: discharge >263°F; 4: discharge <90°F after 1 h; 5: defrost failure; 6: discharge sensor short; 7: outdoor sensor open/short; 9: bonnet sensor fail All brands · Heat Pump
Excess ice on outdoor coil All brands · Heat Pump
Extremely high head pressure in heating (dual fuel) All brands · Heat Pump
Insufficient heat in cold weather All brands · Heat Pump
Liquid slugging / compressor damage in heating All brands · Heat Pump
No mode change / wrong mode All brands · Heat Pump
Odour at registers (dirty sock) All brands · Heat Pump
Poor heating but OK cooling (or vice-versa) All brands · Heat Pump
Service problem analysis (Amana chart excerpt) All brands · Heat Pump
Subcooling too high All brands · Heat Pump
Subcooling too low vs mfr target All brands · Heat Pump
TXV bulb/diaphragm failure All brands · Heat Pump
Water-source: coil freezing All brands · Heat Pump
Won't change mode / both coils same temperature All brands · Heat Pump
Wrong superheat after line-set change; poor capacity All brands · Heat Pump
Force a defrost cycle or skip the 5-minute delay KeepRite · Heat Pump
Forcing a defrost to test the board - KeepRite N4H4/R4H4/WCH4/NXH5 KeepRite · Heat Pump
Outdoor unit will not run or will not defrost - KeepRite heat pump defrost board (FAST 1173636/1177927/1190281) KeepRite · Heat Pump
Speed up the defrost timer for testing (J1 speed-up pins) KeepRite · Heat Pump
Switch the post-defrost outdoor fan delay off or on KeepRite · Heat Pump
Turn 230 V brown-out protection off or on KeepRite · Heat Pump

Source: KeepRite ICP N4H4/R4H4/WCH4/NXH5 Heat Pump Installation Instructions 428 01 5107 10, Table 3 3-Phase Monitor LED Indicators, p.6. 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.