Ice on your fan coil can be caused by :


a) abnormal gas pressure, ice usually develop when suction gas pressure has dropped to ~ 40psi to 45psi. As such, it
could mean that your system has a problem of
gas leak. Special attention must be taken when working on an Inverter
system. Because an inverter air conditioner regulates its compressor rotational speed, it will affect the head and suction
pressure. If it spins too fast, the suction pressure drops too low and thus creating the same results similar to gas leak in a
non inverter system. I will cover more in details in troubleshooting an Inverter system in later sections.















b) a faulty compressor magnetic switch; if icing problem is as severe as to causing the entire fan coil to become a block of
ice, then it is most likely caused by a faulty magnetic switch that doesn't cut out when you power off your indoor air
conditioner; meaning, the outdoor condenser is still running and continuously supply the "cold gas" to your indoor aircon
blower. Since you have powered off the aircon and the fan is not blowing, the supplied "cold gas" is not dissipated, the fan
coil can be so cold that it ice up pretty badly. If you are using a Fujitsu or certain model of carrier (its the same machine),
this is a common problem.






















c) a choked fan coil can cause ice forming on the fan coil. When the fan coil is choked, 2 things happens: First, the
liquefied gas has difficulty fully evaporating and that will cause the suction pressure to drop by 5-10psi. Secondly, when
the fan coil is choked, the fan coil is in fact colder than normal as the coldness is not dissipated well enough.

DO NOT top up the gas upon seeing ice! As mentioned above, ice can be caused by other factors too. If ice is not
caused by
gas leak, topping up gas will screw up your compressor big time. You may like to read this article i wrote
previously,
things technician do to sabotage your aircon.
Copyright © 2011 Aircon Astiquer
Call Kevin @ 90674867
Aircon Astiquerair conditioning Specialist
biz. reg. no: 52959937J