yokohama a/c

[mack]

Hi Guys got a yokohama yshraq-12 with a E3 fault showing.It is low on gas (r410) but if i isolate the outside unit electrically the inside display still shows E3 any ideas thanks Mack.

[gt82000]

Turn off mcb at fuse board. By sounds of it power is to the indoor unit. But you dont need power off before de-canting system and pressure testing for leak.

[mack]

thanks for the reply GT.I wasn't concerned about the electric supply as out here the inside unit has an isolation switch & so does the outside unit.what I meant was that I know its low on gas but with the E3 error message coming up with the outside unit isolated the control board isn't looking at the low/high pressure sensor if it has one.so I didn't want to regas it & still find there is a board fault or similar on the inside unit.thanks Mack.

[cadillackid]

often on a split system the unit will display whichever code comes up first... most of them if you power the indoor unit with the outdoor unit off you will get a communications failure message... so its kind of unusual you get a low PSI sense when outdoor unit is disconnected... unless the algorithm uses a sensor on the indoor unit for sensing low refrigerant....

I know the chigo models look at discharge temperatures.. inlet, middle, and outlet of each coil plus room and ambient temperatures to determine low refrigerant.. as they know with all that data what superheat and subcooling should be....
-Christopher