Midea M-Thermal Series Service Manual page 44

Procedure
Water flow switch connection on
hydronic box main PCB is loose
Water flow is insufficient
Water flow switch is damaged
Internal circulator pump can't work
Replace hydronic box main PCB
Notes:
1. Water flow switch connection is port CN8 on the main PCB for hydronic box (labeled 6 in Figure 4‐2.1 in Part4, 2.2 "Main PCB for Hydronic System").
2. Check water pressure on the manometer. If the water pressure is not > 1 bar, water flow is insufficient. Refer to Figure 2‐1.6 in Part 2, 1 "Hydronic Box
Layout".
3. Revolve the pump shaft reversely around the clock, check the wire in the pump.
201909 43
E0 / E8
1
No
2
No
No
No
Midea CAC Confidential
Yes
Ensure the switch is connected properly
Check the water piping and valves. Make
sure the water piping is clean, there is no
air in the water piping and all valves are
Yes
open. If the internal circulator pump is
not already set to the highest speed,
increase its speed.
Yes
Replace the water flow switch
Yes
Turn off the power, check the pump
step 1, revolve the pump shaft reversely
around the clock by hand, if can't
revolve, replace the pump
step 2, check the wire in the pump. Once
that is done, the pump still can't work,
replace the pump.
M‐Thermal Split