MITSUBISHI ELECTRIC MSZ-GF60VE (R410a) Problem

[Gordon]

I installed this system for a customer 2 years ago but they are now experiencing problems with the indoor unit. The fan will not operate above minimum setting and is not moving enough air to provide adequate cooling, particularly in the current hot weather. The unit is fully charged with refrigerant, no leakage, and the outdoor unit is working normally. I have tried resetting the remote control but cannot get the fan to run at high speed. I am probably missing something straight forward. Any suggestions on the problem would be welcome.

[frank]

Have a good look at the scroll with the unit off to see if it is clogged with detrius. May need a strip down clean