Air Conditioning - Split type freezes up when A/C switched OFF
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juliankay
09-26-09, 05:59 AM
I have a Mitsubishi split type A/C, installed about 8-9 years ago, but only lightly used during the last year or two (the house had been left empty after we installed the units). In the time that we've used it, everything worked fine, very quiet and cooling very quickly.
Last week, on start up, the indoor unit spewed out ice particles and then after a while it ran normally. When switching off the unit -via remote control- I notice there is still some sound coming from within the air handling unit; like water or liquid (refridgerant?) moving about from within. The blower fan is off as per normal. On closer inspection, the evaporator coils begins to freeze as does the refidgerant pipe connector to the outdoor condenser unit.
The ice build up on the evaporator coils is so bad that it freezes the air filters as well. The build up on the condenser unit completely surrounds the pipework leading to the condenser unit -and this is when the ambient temperature is 30+ degrees celcius! This is when the system has been switched off via remote control. When the system is turned off at the wall isolator/ main switch, the liquid movement noise stops and both areas where ice build up occured, defrosts.
I've spoken to a couple of A/C engineers and they all point to not having enough gas without providing a satisfactory explanation as to why the freezing occurs when the system is in a powered off state. Both air filters and evaporator coils are clean.
One of the engineers I spoke to did mention that there are other filters inside the evaporator coils and it's a 'big job' to dismantle and clean them, so I may as well install a new system. Is this correct or am I being misled?
Has anybody experienced a similar situation or can shed some light on my problem before I call out an engineer?
My hunch is that it could be something to do with the electronics (circuit boards) which control the system's on/off cycle or am I missing something here?
Any pointers appreciated.
TIA,
Jules
Last week, on start up, the indoor unit spewed out ice particles and then after a while it ran normally. When switching off the unit -via remote control- I notice there is still some sound coming from within the air handling unit; like water or liquid (refridgerant?) moving about from within. The blower fan is off as per normal. On closer inspection, the evaporator coils begins to freeze as does the refidgerant pipe connector to the outdoor condenser unit.
The ice build up on the evaporator coils is so bad that it freezes the air filters as well. The build up on the condenser unit completely surrounds the pipework leading to the condenser unit -and this is when the ambient temperature is 30+ degrees celcius! This is when the system has been switched off via remote control. When the system is turned off at the wall isolator/ main switch, the liquid movement noise stops and both areas where ice build up occured, defrosts.
I've spoken to a couple of A/C engineers and they all point to not having enough gas without providing a satisfactory explanation as to why the freezing occurs when the system is in a powered off state. Both air filters and evaporator coils are clean.
One of the engineers I spoke to did mention that there are other filters inside the evaporator coils and it's a 'big job' to dismantle and clean them, so I may as well install a new system. Is this correct or am I being misled?
Has anybody experienced a similar situation or can shed some light on my problem before I call out an engineer?
My hunch is that it could be something to do with the electronics (circuit boards) which control the system's on/off cycle or am I missing something here?
Any pointers appreciated.
TIA,
Jules
airman.1994
09-26-09, 07:50 AM
Don't think you need an engineer for this. Sounds like when using the remote the condenser still runs. I would expect a board issue.
juliankay
09-26-09, 02:33 PM
the board in the air handling unit or the remote control not giving the right instructions?
juliankay
10-07-09, 11:53 PM
tried switching to fan only and the system is blowing out cold air like when on cooling setting; cicuit board fault? anyone?
dun11
10-08-09, 09:00 AM
As stated, it sound like the cond unit is running non stop, need to varify