KeepRite Heat Pump: Speed up the defrost timer for testing (J1 speed-up pins)
Speed up the defrost timer for testing (J1 speed-up pins) on a KeepRite heat pump: Shorting the J1 speed-up pins shortens the defrost timing. On Quiet Shift-2 boards hold about 5 seconds and release; defrost thermostat open gives only a short defrost, closed a full cycle.
Applies to: N4H4/R4H4/WCH4/NXH5 heat pumps; older split heat pump defrost boards
How to fix speed up the defrost timer for testing (j1 speed-up pins): step by step
- Put the unit in heating and let the coil frost (defrost thermostat must be closed for a full cycle)
- Short the J1 speed-up pins with a flat screwdriver for about 5 seconds, then release as soon as the reversing valve changes position
- The unit stays in defrost for the remaining cycle time or until the defrost thermostat reopens
- After the test reconnect anything you disconnected
If the unit shows an error code, look it up: KeepRite Heat Pump codes
Models
Source: KeepRite ICP N4H4/R4H4/WCH4/NXH5 Heat Pump Installation Instructions 428 01 5107 10, Defrost, Defrost Speedup, Table 4, p.8; split service manual Defrost Speedup, p.13 and p.41. 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.