M thermal Mono 
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2 Outdoor Unit PCBs   
2.1 Types 
M thermal Mono outdoor units have two main PCBs – one for the hydronic system and one for the refrigerant system. The 
hydronic system main PCB is the same on all M thermal Mono models.   
The  locations  of  each  PCB  in  the  outdoor  unit  electric  control  boxes  are  shown  in  Figures  4-1.1  to  4-1.4  in  Part  4,  1 
“Outdoor Unit Electric Control Box Layout”. 
 
2.2 Main PCB for Hydronic System 
Figure 4-2.1: Outdoor unit main PCB for hydronic system   
 
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