Troubleshooting - Honeywell T4 User Manual

Troubleshooting

If you have difficulty with your Thermostat, try these suggestions.
Most problems can be corrected quickly and easily.
All models
Screen is blank
Thermostat shows
Thermostat is flashing
+
Thermostat shows
the boiler does not switch
on.
Heating system does not
respond to temperature
adjustments.
Thermostat shows
Replace the batteries (T4 & T4R only).
Check the OpenTherm boiler has power (T4M only).
Contact installer.
Batteries have less than 10% power and need to be
replaced soon.
Batteries are critically low and need to be replaced
immediately - see 'Changing the Batteries'.
The boiler cycles on and off as it controls the
but
temperature, and sometimes the
displayed when the boiler has cycled off.
If the boiler doesn't switch on after a long period of
time contact your installer
Make sure the set temperature is higher than the
actual room temperature.
Check the heating system is powered on.
Check the Receiver Box is powered and the
Thermostat has a wireless signal (T4R only).
The temperature sensor of your Thermostat
is faulty, contact your installer to repair
or replace the Thermostat.
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