1. It may be because the hot air just turned on by the air conditioner is unstable, and it is normal to blow cold air. Generally, it takes 10 minutes to start blowing warm air.
2. Or due to long-term use, part of the refrigerant in the air conditioner leaks, resulting in insufficient refrigerant in the air conditioner. At this time, the hair dryer is sometimes not hot, and sometimes it is cold air, so it is necessary to add freon to the air conditioner.
3. The air conditioner has been used for a long time, and too much dust in the filter will affect the air-conditioning blowing ability, so the air conditioner is not heated well and the blowing temperature is not much. Clean the dust on the filter.
Second, the maintenance method of Hitachi central air conditioning heating and blowing cold air.
1. The most common problem is that the heating box is blocked. The reason is that the water tank of the heater is blocked by water rust by using inferior antifreeze or adding water for a long time.
Solution: Remove the instrument panel and take out the heating water tank. If the heating water tank can be opened, then open the lid and dredge it. Dredge should not be too hard to avoid squeezing the radiator pipe of the water tank. If the lid won't open, buy a bottle of rust remover and add it to the heating water tank. Let it rinse with tap water for one hour (as the case may be) to clear the blockage.
2. The hot water switch at the engine water pump is not turned on, which is easily overlooked.
3. The engine loses water or washes the cylinder pad, which will also lead to no hot air in the warm air.
4. Do not turn the blower, and check the safety and wiring.
5. Dust-covered warm air water tank will also lead to heat reduction.
6. Water pump failure is usually accompanied by high engine water temperature.
3. What if Hitachi Central Air Conditioning doesn't heat?
1. Low outdoor temperature.
When the outdoor temperature is very low, the central air conditioner needs to disperse energy to defrost, and the heating effect of the air conditioner will naturally decrease. We can defrost the air conditioner manually. If the central air conditioner of water system is installed at home, you can also turn on the wall-hung boiler to help defrost the air conditioner and solve the problem that the central air conditioner does not heat.
2. Freon is insufficient.
At present, most air conditioners are heat pumps or heat pumps plus auxiliary electric heating. Both air conditioners use freon to evaporate into the outdoor air to absorb heat. Without fluorine, you can't absorb heat, and the air conditioner won't heat up. In this case, you need to contact a professional to add fluoride.
3. The air conditioner four-way valve leaks air.
Four-way valve, hydraulic valve term, is a control valve with four oil ports. Four-way valve is an indispensable component in refrigeration equipment. Its working principle is that when the solenoid valve coil is de-energized, the pilot valve core moves to the left driven by the right compression spring, and high-pressure gas enters the capillary tube and the right piston cavity. On the other hand, the gas in the left piston chamber is exhausted. Due to the pressure difference between the two ends of the piston, the piston and the main valve core move to the left, so that the exhaust pipe is connected with the outdoor unit, and the other two are connected to form a refrigeration cycle. After replacing the four-way valve, the heating failure of the central air conditioner can be solved.