Hi everyone,

I have a Mitsubishi 3.5kw split unit which is normally charged by weight. On these splits there is a service port only on the suction line so it is possible to measure superheat but not subcooling because liquid line pressure cant be measured.

Is it possible to use superheat to determine if charge is correct?

Or would it be a case of full recovery and recharge by weight again?

One final question do these domestic splits use a TXV or a fixed restrictor because if they use a TXV then it is my understanding one would check charge using subcooling which I cannot do.

Thanks for any help.