M thermal Mono
202008 87
4.27 Hd Troubleshooting
Digital display output
4.27.1
Description
4.27.2
Communication fault between master unit and slave unit (in parallel)
M thermal Mono stops running.
Error code is displayed on hydronic system main PCB, outdoor unit main PCB and user interface.
Possible causes
4.27.3
SW9 DIP switch with wrong settings
More than two units are connected to the wire controller
Power-on interval between master unit and slave unit is longer than 2min
Wire connection error
Communication between units is unstable
Address code missing or address code setting duplicate
Main board fuse is damaged
Procedure
4.27.4
Hd
SW9 DIP switch with wrong settings
Yes
Check SW9 setting. Master unit: ON; Slave unit: OFF
No
More than two units are connected to the wire controller
Yes
Make sure there is only one controller connect to
master unit.
No
Power-on interval between master unit and slave unit is
longer than 2min
Yes
Make sure power-on interval between master unit
and slave unit is less than 2min
No
Wire connection problem
Yes
Reconnect the wire according to the group control
system wiring diagram in Part 2. Make sure wires
are connected effectively and no strong electricity
or strong magnetic interference.
No
Communication between units is unstable
Yes
Add network matching wire between ports H1 and
H2 at the terminal of the communication system
No
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