city multi

[richard..]

hi there
was working on two mits unit the other day and i had a problem with the outdoor coils icing up.no fault codes were showning and the client only knew he had a problem once they lost heating from the indoor coils.they switched off outdoor units to defrost them.when i arrived i checked themisters found no faults with readings.set outdoor dip switches to increase defrost timmer from 50 mins to 90 mins and also defrost start temp and defrost stop temp.left unit running and will check operation in a few days.the units are PURY P250 YGMA this site has around ten units and only the two ground floor units iced up.the only dif i found was these units have one indoor on 24/7. not sure that me adjusting the dip switches will be the main problem solved can,nt see it being a gas prob as both units are doing the same fault

[CraigMac0113]

Hi Richard,
Just wondering if you had any more details on this one.
How long have these units been operating?
What running pressures are you getting?
Have you tried running only half the indoor units on these systems?

[richard..]

the units have been on site for i think around 2 to 3 years
the suction pressure was just over 6 bar
did not get round to doing the temperature on/off test on cooling as time was running short for me.but having two systems with the same fault i would not like to think they are both short off gas. but stranger things have happened.i will take temp readings with units all on and half off