Operating instructions
52
Error shows when safety circuit is 
open. Remove J13 connector from 
control module. Check for continuity 
between two pins connected to two 
pink wires, is continuity available?
YES
NO
Replace Control Module
Boiler red without enough water ow 
through heat exchanger. Heat exchanger 
is over heated. Either high limit or heat 
exchanger temperature switch is open. 
Check the following:
• Air in system?
• Verify water ow in system piping
• Flush system if water is dirty.
Is boiler supply pipe (above 
heat exchanger) hot?
Wait for boiler to 
cool down.
YES
NO
Replace Broken Switch
Unplug molex connector on supply 
temperature sensor. Check continuity 
between two pins on sensor two 
pins connected to two pink wires 
before  removing  the  connector. 
Is continuity available?
YES NO
Check for loose connections 
on two pink wires on J13 
connector, supply sensor, and 
safety temperature switch.
YES
NO
Fix Loose Connections Replace Wire Harness
Let all zones 
run until water 
temperature 
drops.
Is Heat Exchanger surface 
hot?
YES
NO
Check high limit 
and surface 
temperature 
switches
13 - TROUBLE SHOOTING










