mitsubishi heavy industry problem

[oggleboggle]

hi

going to a job this week someones already been and they said two units on the systam aint heating,the system is a misubishi heavy industry 3 pipe system each unit has its own bs box i was thinking short of gas or solinoid valve in bs box as gone,if anyones got any ideas thanks

[stufus]

First things first ,do they operate in cool mode , is the eev in the indoor ok.A system that is short of gas will usually experience a loss of duty across the board if all units are operating under the same mode.Turn off the other units and run the two suspects on their own to see how they go .
Check the control wiring and solenoids at branch selectors if the above ideas come up short..
Cheers
Stu