Specifications

Troubleshooting | 25SM CS Series Heat
8 733 920 846 (2013/11)Revised 11-13
Unit Lockouts
Periodic lockouts almost always are caused by air
or water flow problems. The lockout (shutdown) of
the unit is a normal protective measure in the
design of the equipment. If continual lockouts
occur call a mechanic immediately and have them
check for: water flow problems, water
temperature problems, air flow problems or air
temperature problems. Use of the pressure and
temperature charts for the unit may be required to
properly determine the cause.
YELLOW "ALERT"
FLASH CODE 8
Welded Contactor
Compressor always
runs
1. Compressor contactor has failed closed
2. Thermostat demand signal not connected to module
YELLOW "ALERT"
FLASH CODE 9
Low Voltage
Control circuit <
17VAC
1. Control circuit transformer is overloaded
2. Low line voltage (contact utility if voltage at disconnect
is low)
• Check wiring connections Flash Code number
corresponds to a number of LED flashes, followed
by a pause and then repeated. TRIP and ALERT LEDs
flashing at same time means control circuit voltage
is too low for operation
Comfort Alert Module -Flash Codes
Status LED
Status LED
Description
Status LED Troubleshooting Information Solution
HRP Troubleshooting
Problem Possible Cause Checks and Corrections
NO FLOW
LOW FLOW
No Power Check power supply
On/Off Switch Position
Set switch to “ON” position
Compressor Contactor
Engage heat pump contactor
Broken or loose wires
Repair or tighten wires
Air Lock
Purge air from piping system
Stuck pump shaft/impeller
Remove pump cartridge and clean
Defective pump
Replace pump
Kinked or under sized water piping
Repair kink and check for proper line size
HIGH WATER
TEMPERATURE
Water temp limit closed Stuck limit switch
Sensor not attached securely to line
LOW HEAT OUTPUT Scaled or fouled heat exchanger Clean heat exchanger