[Prowler]

Originally Posted by Ragul

Since two weeks the compressor runs for a minute then shuts down for 4-5 mins. The outdoor unit compressor fan spins up and whines at its usual rpm and the cool air starts flowing through the indoor unit, then the fan slows down and runs at low/idle for another 30 sec and eventually dies off. This cycle repeats for 24x7.

Check the outdoor unit's fan. If it stops on its own, check if the compressor continues to run for a while before it shuts down. If this is the case, the out door fan motor's running capacitor may be the culprit. If this fan is not running, the compressor will shut down.

[Jaggu]

Originally Posted by Ragul

What can be the problem? The software/remote diagnostic tests all show normal/pass.

Sounds like a faulty temperature sensor which is triggering with a short run of the compressor, next can be a low gas scenario, and finally can be an electric issue that is getting aggravated with electrical load.

My guesses.. apart from what prowler mentioned above ^

[spookey]

Originally Posted by GTO

One of my 2-year old Hitachis is falling apart! Went kaput for the 3rd time in a year.

Stuck with 5 of these. Please dont fall for brand HITACHI and waste your hard earned money. Very poor quality and pathetic service. They have outsourced their after sales service to third parties like VS aircon for Mumbai which is only interested in conning customers while the company turns a blind eye.

[Ragul]

Originally Posted by Prowler

Check the outdoor unit's fan. If it stops on its own, check if the compressor continues to run for a while before it shuts down. If this is the case, the out door fan motor's running capacitor may be the culprit. If this fan is not running, the compressor will shut down.

Yes that's exactly the case. Looks like I will have to wait till most of summer is over to get it fixed unfortunately.

The humidity in my home is climbing from 60s to 70 unfortunately and it's getting stuffy, but I'm not sure I want to entertain a mechanic inside my home until I get my second shot.

I will have the temperature sensor checked as well... How do I test if it's a load problem? The 15amp electrical wiring is separate from the 6amp in the entire building and I don't experience a power cut in the 15 amp line while the AC compressor shuts down.

[Ragul]

Originally Posted by Jaggu

Sounds like a faulty temperature sensor which is triggering with a short run of the compressor, next can be a low gas scenario, and finally can be an electric issue that is getting aggravated with electrical load.

My guesses.. apart from what prowler mentioned above ^

PS - I forgot to ask, is it ok to run the AC like this for the next one month? Or will it cause further damage?
Also if it gives a clue the problem vanished for a few days when I switched the AC off for a few hours last week then reappeared. What does that tell you? I am going to switch off now till midnight and check again.

[Turbanator]

^^

Is your indoor filter clean? Try cleaning it once and see if that helps. Also, some of the Air conditioners have a power mode that usually bypass the temperature setting function. Check if it runs fine in this mode. If both these don’t work, try cleaning outdoor unit cooling coils with water spray. Not pressurized, just gentle.

[Prowler]

Originally Posted by Ragul

PS - I forgot to ask, is it ok to run the AC like this for the next one month? Or will it cause further damage?

If its is the ODU's fan motor, running for long duration under this condition will damage the motor. It costs around Rs.2500/- in most units. The capacitor will cost about Rs.250-400/- Labor to replace will be about Rs.300-500/- under normal circumstances.

[Aroy]

Originally Posted by Ragul

PS - I forgot to ask, is it ok to run the AC like this for the next one month? Or will it cause further damage?
Also if it gives a clue the problem vanished for a few days when I switched the AC off for a few hours last week then reappeared. What does that tell you? I am going to switch off now till midnight and check again.

If the ODU fan is not working, then it can be as simple as changing the capacitor of the fan, unless that too is a DC fan.

If the fan is working then it can be anything from low gas to faulty sensor.

Anyway, till the problem is solved it is wiser not to run the AC.

NOTE
If the fan is the culprit and there is no AC mechanic available, just open the ODU and see if you can access the fan capacitor. Note down the particulars - Voltage, Farads etc and buy one, either from the market or online. Changing capacitor is very easy as most of the time it is attached by terminal with screws.

[Lobogris]

Originally Posted by Ragul

Yes that's exactly the case. Looks like I will have to wait till most of summer is over to get it fixed unfortunately.

The humidity in my home is climbing from 60s to 70 unfortunately and it's getting stuffy, but I'm not sure I want to entertain a mechanic inside my home until I get my second shot. .

It really isn’t that dangerous to have a mechanic in the house. Simply open the windows and doors just before his arrival and turn on the fans. Wear a mask, an N95 if possible and maintain your distance. After the brief explanation of the issue delivered from a few feet away, you can go stand by a door or window away from the mechanic or even in another room. Leave the windows open for another few minutes after he leaves while you wait in another room. Then simply sanitise any area he might have touched. All this is a bit over the top but since you are worried, this should eliminate most of the risk.

[Ragul]

Originally Posted by Lobogris

It really isn’t that dangerous to have a mechanic in the house.

Originally Posted by Aroy

If the ODU fan is not working, then it can be as simple as changing the capacitor of the fan, unless that too is a DC fan.

If the fan is working then it can be anything from low gas to faulty sensor.

Anyway, till the problem is solved it is wiser not to run the AC.

Originally Posted by Prowler

If its is the ODU's fan motor, running for long duration under this condition will damage the motor. It costs around Rs.2500/- in most units. The capacitor will cost about Rs.250-400/- Labor to replace will be about Rs.300-500/- under normal circumstances.

Thanks everyone! Right now is lockdown anyways so either is self service with online capacitor purchase or a long wait.

This is branded as a double inverter AC. would that be a DC fan? How do I check that?

[Aroy]

Originally Posted by Ragul

Thanks everyone! Right now is lockdown anyways so either is self service with online capacitor purchase or a long wait.

This is branded as a double inverter AC. would that be a DC fan? How do I check that?

Yes the fan may be DC.

If the fan is AC there will be capacitor bolted on to the body. The best method is to
. Open the ODU
. Identify the fan.
. Clean the fan body.
. Take a photo of the lable on the fan.
. If it is AC then there should be a tube (capacitor) bolted on to the body. The lable will also give you details of the fan.

[Ragul]

Originally Posted by Aroy

Yes the fan may be DC.

If the fan is AC there will be capacitor bolted on to the body. The best method is to
. Open the ODU
. Identify the fan.
. Clean the fan body.
. Take a photo of the lable on the fan.
. If it is AC then there should be a tube (capacitor) bolted on to the body. The lable will also give you details of the fan.

Strangely the AC is back to normal after struggling for two full weeks. I shut it off for 2-3 hrs - no effect. Then I ran it on fan/blower mode for 2-3 hrs where OD does not run - no effect initially. Then I wake up to find the AC is running smoothly like before - it fixed itself overnight! (This happened one month back as well ... problem for two weeks then normal).

The only change I did is to switch from Auto to a fixed 24 celsius a day before. This is how I have been running the AC for many years. While in the initial years the Auto worked fine it seems now it seems it is messing up something in the medium term. In between I also experimented with a temp setting of 18 celsius for a day or two when the problem was ongoing. I read that setting a temp too low can cause freezing somewhere in the OD unit and block airflow. However switching off for 3hrs should have induced melting and auto-repaired the problem - but it did not.

I am really curious to find out why this is happening. Can it be that yesterdays thunderstorm and rain with lower outdoors temperature has to do something ? But then why did it struggle even at night and 4am last two weeks when the temps are low? AC is in covered balcony so rains did not wash/clean anything.

[Aroy]

May be the Auto mode was messing up the operations.

[eyesice]

Hello Bhpians,

I have a 7 year old Hitachi split a/c. Last month, there was literally no cooling from the A/C and I called Hitachi service centre. The service person came and said that there is a lot of dust in the coil and other internal parts and a full water wash is required. I agreed and things were fine for about a week and since then the problem has resurfaced. The A/C pipes connecting the indoor to the outdoor unit turns icy if I keep running the unit for about 2 hours.

What could be the root cause of this issue? I am unable to call for service as there is a complete lockdown in chennai.

[Aroy]

Originally Posted by eyesice

Hello Bhpians,

I have a 7 year old Hitachi split a/c. Last month, there was literally no cooling from the A/C and I called Hitachi service centre. The service person came and said that there is a lot of dust in the coil and other internal parts and a full water wash is required. I agreed and things were fine for about a week and since then the problem has resurfaced. The A/C pipes connecting the indoor to the outdoor unit turns icy if I keep running the unit for about 2 hours.

What could be the root cause of this issue? I am unable to call for service as there is a complete lockdown in chennai.

Check the airflow of the IDU. Ideally the air flow should be felt at 10 feet distance. To check airflow :
. Run the AC fan at maximum setting (highest airflow)
. Take a single sheet of paper. Newspaper piece will do.
. Hold it at the top 1 foot away from the outlet. If it bends a lot due to airflow, fine.
. Now keep going backwards and check the airflow. Stop when the paper barely moves. If this distance is less than 8 feet your airflow or fan is the problem

Now if the airflow is low, the IDU condenser may freeze up, and the freeze may extend to the gas pipes.

I have had my IDU coils choking due to dust regularly. The only recourse is to do a thorough washing every 4-5 months.
. When they wash the IDU they will put a shroud and spray water. Keep noting the colour of water that comes out. It will be muddy initially.
. Insist that they keep washing till the water runs clear, otherwise they will stop after 5 minutes.
. Once the water in the collection bucket get half full, throw it, so that you can check the progress.
. Keef the washing till the water in the bucket is clean.