if the conditioner is working properly, no prophylactic work has been done, and no rules of exploitation have been violated, but suddenly the ice begins to fall out of it, probably there is a malfunction.

1. The indoor unit is contaminated
As a result of long exploitation such components as filters, ventilators, and evaporators “grow” with dust and dirt. As a result, heat removal from the evaporator decreases, and on it freezes.
Signs: The air conditioner does not cool well and ice forms from it. Ice builds up in the air conditioner. In some cases, a crackling sound may be heard and water may drip from the indoor unit.
How to fix it: Clean the inside unit thoroughly.

2. Contamination of the outdoor unit
Over time, the heat exchanger (condenser) and outdoor unit fan become clogged with dust, down, and other debris. Because of this, the heat output from the heat exchanger decreases, and the cooling capacity of the air conditioner decreases. The split system is trying to compensate for its drawback at the expense of the constant work of the compressor motor. It rarely shuts down, causing ice to form in the indoor unit.
Signs: The air conditioner does not cool well, and ice falls out of it. In some cases, a crackling sound is heard and water may drip from the indoor unit.
How to fix: Cleaning of external unit is necessary. Usually, it is washed with water from the special high-pressure washer.

3. Freon leakage
The refrigerant can escape both because of depressurization and during long exploitation: even in working order split unit “loses” up to 7% of freon per year. Because of the lack of refrigerant, the productivity of the air conditioner decreases, trying to “catch up” the temperature it works without stopping, as a result of which the evaporator freezes.
Signs: The split system cools weakly, but the compressor works almost without stopping. Ice is flying or water is leaking from the indoor unit. Models with self-diagnosis of malfunction, give a message about lowering the pressure in the system.
How to fix it: Check the tightness of the line by pressure testing the air conditioner with nitrogen at excess pressure. If the pressure of nitrogen begins to drop within a few minutes, the fact of the leak is obvious. The wizard finds the place of the leak (it is often the bolted connections of the air conditioner tubes) and fixes it. After that replacement of the filter-dehydrator, evacuating the system, and charging it with freon is made.

In case of natural leakage, the air conditioner is simply refilled with the refrigerant.

4. Clogging of capillary pipe (in conventional non-inverter models)
If a clog occurs in the capillary tube, the pressure drop between the inlet and outlet of the tube increases. This causes some of the Freon to boil and give up the cold before the evaporator. It causes the total refrigerating capacity of the air conditioner to drop. Trying to compensate for it, the motor hardly ever shuts down, and because of its constant operation, the evaporator is covered with ice.
Signs: The air conditioner operates, but does not cool well. At the same time, the motor rarely shuts down. There is ice and snow on the evaporator of the split system. When thawing, it drips into the room. If you look at the external unit, you can notice the frosting on the thin tube.
How to fix it: Depending on the complexity of the blockage, the technician:
– Blows out the system with pressurized nitrogen (in case of a partial clog);
– uses hydraulic cleaning and solvents (in case of a heavy blockage);
– Replace the capillary tube if the cleaning doesn’t help.

5. Failure of settings or malfunction of the TRV/ERV valve (in inverter air conditioners)
Inverter models of split systems flexibly regulate the freon flow to the evaporator by means of an electronic type thermostatic expansion valve (EBV) or a mechanical type expansion valve (TRV). Due to this, the air conditioner maintains the set temperature more accurately at lower power consumption. If this node is out of order or its settings are wrong, the freon pressure in the system does not correspond to the working pressure, the refrigerant only partially boils in the evaporator, and the refrigerating capacity of the air conditioner decreases. In order to keep the set temperature, the split has to turn on more often and work almost without stopping. This causes the indoor unit’s evaporator to freeze.
Signs: The air conditioner works, but does not cool well. At the same time, the motor rarely shuts off. Ice and snow freeze on the evaporator of the split system. As it melts, it drips into the room. If you look at the external unit, you can see frosting of the thin tube.
How to fix: Adjustment or replacement of defective expansion valve/expansion valve is necessary.

6. Failure of the control board (in split systems and inverter air conditioners).
This leads to low condensation temperatures on the evaporator and, as a consequence, to the formation of ice in the indoor unit. The frost melts and flows into the apartment. If water or formed snow gets on the fan, the air conditioner “spits” water or ice. When there is too much frost in the split system, the fan blades hit the frozen “coat,” and a crackling noise occurs.
Signs: Internal unit of air conditioner is freezing, maybe ice is falling out, water is dripping or split system is cracking.
How to fix: Requires repair or complete replacement of the failed control board.

7. Fan Failure
It rotates only at low speed. This causes low heat removal from the evaporator and its frosting. Frozen ice leaks when it thaws.
Signs: The split system is not blowing properly, and may be leaking.
How to fix: Need to repair or replace the indoor unit fan

8. Failure of evaporator temperature sensor (in some split-system models)
It turns off cooling if the evaporator temperature gets too low. If the temperature sensor is out of order the control board does not receive a signal that it is necessary to take a compressor break. This causes ice to freeze in the air conditioner, which melts and leaks into the room.
Signs: The air conditioner in your apartment is freezing. Water may be dripping from it and ice is falling. The compressor is running and will not shut off.
How to fix: Requires replacing the sensor with a new one.

If you notice ice and snow forming inside the split system – we recommend disconnecting the technique and calling a master. Operation of faulty air conditioner can lead to more serious breakdowns of split-system. Don’t hesitate to call us anytime.

A specialist with SDAC Heating & Air Conditioning will come to your call. He’ll diagnose in front of you and determine the reason why your air conditioner is freezing. He will calculate the cost of fixing the breakdown and, with your consent, perform in-home repairs.

Contact us.

(858) 788-1777

[email protected]