Troubleshooting; Temperature Related Faults; Programmable Room Thermostat And Receiver; Related Faults - Worcester Greenstar Comfort II RF Installation And Operating Instructions Manual

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Troubleshooting

7.1

Temperature related faults

Problem
The required room
temperature has not been
achieved.
The room temperature is higher
that the set value
7.2 Programmable Room thermostat and Receiver related faults
7.2.1 Programmable Room thermostat
Faults will be display alternating between the fault code and the cause code.
Fault Cause
code code Problem
A21 1001 No RF signal
A22 1002 No RF signal or pairing
fault
A23 1003 Room stat internal sensor
failure
A24 1004 Remote RF unit has a fault Another room thermostat in the system has a
A27 1007 Unable to communicate
with boiler's EMS bus
A28 1008 Not paired
Blank display or low battery symbol
7.2.2 Receiver
If the LED is flashing at one flash per second then the Receiver has detected a fault.
Fault Problem
Possible Flashing
1 flash per second
fault
(1 Hertz)
condition
Comfort II– 6720810965 (2014/07)
Cause
Airlock
Low system pressure
Time program
Flow temperature
Thermostat valve in reference room
Check the Room thermostat location
refer to section 3.2
All units powered and not showing low
battery symbol
All units powered and not showing low
battery symbol
Internal room temperature sensor out of
valid range
problem
Boiler is EMS compatible but no
communication
Unit is not paired
Batteries are spent
Description
Local programmer error.
Not a boiler fault, possibly no RF connection with the
Programmable room thermostat(s), at least one connection
has been lost
Bleed the radiators and vent the heating system.
Top up the system pressure via the filling link
Is the heating on for long enough
Set a higher flow temperature
Operate the TRV to ensure that it does not stick
Fully open the TRV
Move the Room thermostat to a more suitable location
Description
Troubleshooting
Remedy
Remedy
Check signal strength and reposition
Room thermostat for better signal
Repeat pairing
Replace RF Room thermostat
Check other room thermostats within
the system for fault codes
Replace EMS interface
Unpair and pair all
Replace batteries
Remedy
Check the Programmable Room
thermostats for fault code.
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