Appendix
26
In case of difficulty
Programmer screen
is blank
• Check the heating system to make sure the programmer has
electrical power.
Radiators are cold, or no
hot water is available
• Check to ensure the heating and hot water channels on the
programmer are turned on. The indicator lights should be lit.
• Make sure the room thermostat and cylinder thermostat are
switched on and set to appropriate temperature levels.
• Check the boiler to see if it is operational.
• Check wiring (pages 17-20) and system configuration (pages 21-
23).
Screen displays “Not
Valid” when slider is in
Hot Water position
• Your THR860SWE has been configured as a “Mini-Programmer”
during installer setup. This is only valid for an uncontrolled gravity
hot water system. If you have a fully pumped system (see page 23),
to reconfigure the system for normal operation by using Function
7, or contact the professional installer who configured your
system.
