Airconditioner Technicians

[jbrain]

I posted some time ago already that I had some issues with an inverter aircon from the famous D..... brand that didn't function the way it should.

So a few weeks ago I had a random technician come around to clean and top up 2 identical aircons installed in the bedrooms in the hope that would clear the issues, but that wasn't the case.

So I started checking. Both aircons are 12000 Btu inverter aircons from the same brand.One is installed in a 22 Sqm room and functions perfect ( let's call this aircon 1) , and the other one is installed in a 15 sqm room and function not good. Both aircons are 20 months old.

I measure the temperature at the indoor unit from Aircon 1 with setting 18 degrees on the remote and after 10 minutes it reads 1 degree with the blower on low then goes up to 7 probably to prevent freezing and 11 degrees with the blower on high.

The second one measures 14 degree on low and 17 degrees on high withh he same settings . So I think it;s clear there is something wrong.

I travel to the companies service center and explain my problem. They tell me that the indoor unit has 1 year warranty and the compressor 5 year. However if the compressor has to be replaced it cost me 3000 Baht anyway because labor and materials used are not covered

To check the aircon cost 428 Baht, which I have no problem with, so an appointment is made for this afternoon.

So 2 technicians arrive and start to check. refrigerant is sufficient as are power and current. At the tube leaving at the outdoor unit they measure 11 degree, but after running for about an hour that decrease to 7 degree.

At the indoor unit they measure 16 degree and after heaving the aircon running on it's maximum power for an hour ande a half the temperature in the room is 24.7 degree.I think at that point one can understand that the temperature will not get any lower

As I said the room is 15sqm, has 25 cm cavity walls, 6" insulation on the ceiling and 2 rather small pvc windows with insulated glass and it had been raining all afternoon

Yet the technicians complete their inspection and declare everything normal

I point out the measurements I make in the other room with the identical unit, but they say because it's a bigger room the aircon blows colder.

When I say that if I open the doors and the windows from the smaller room I would have a room of unlimited acreage and then the aircon should blow even cooler, they don't have an answer.

On my question why after running aircon on maximum power for 1.5 hour they can't get a 15sqm room with ambient temperature of 29 degree below 24.7 degree they also don't have an answer.

Nothing wrong sir, of course as soon as the warranty has expired they will find the problem, not ?>

So far my rant. I guess the 27.000 Baht + installation cost i spend 20 months ago was a good investment.

My next aircon wil definitely not be from the D..... brand.

Edited September 12, 2013 by jbrain

[bangkokstick]

I also have an inverter of the same brand and as it works well I didn't do anything, not even cleaning for more than 2 years, I am so scared that the MIB (monkeys in blue :-) ) will break it when they will touch it !

Sorry to ask but have you used the brand technicians to clean your units or another company ?

Thanks a lot.

[Naam]

At the indoor unit they measure 16 degree and after heaving the aircon running on it's maximum power for an hour ande a half the temperature in the room is 24.7 degree.I think at that point one can understand that the temperature will not get any lower...

refrigerant flow is blocked between expansion valve and evaporator. no idea how that can happen except if pressure pipe diameter was reduced by bending (highly unlikely, but then... This Is Thailand!).

[Naam]

My next aircon wil definitely not be from the D..... brand

same here!

[OMGImInPattaya]

Surprised any brand air con these days has only a 1 year compressor warranty...standard is 3/5 for indoor unit and compressor and some even have 5/5 warranties. Especially unfortunate from a premium priced brand like "D."

I've been happy with my LG Inverter V aircon in one room the past 3 years and plan to go get another one for another room today.

Edited September 13, 2013 by OMGImInPattaya

[jbrain]

At the indoor unit they measure 16 degree and after heaving the aircon running on it's maximum power for an hour ande a half the temperature in the room is 24.7 degree.I think at that point one can understand that the temperature will not get any lower...

refrigerant flow is blocked between expansion valve and evaporator. no idea how that can happen except if pressure pipe diameter was reduced by bending (highly unlikely, but then... This Is Thailand!).

A blocked flow was somethin I also had taken in consideration, so you may be right there. Electricians have been on the ceiling nummerous times and the ceiling is cracked in the area where the piping runs because one of the morons probably stepped on it.,

Time to get on the ceiling myself I guess.

[Naam]

Time to get on the ceiling myself I guess

problem is that the pipes are insulated and i can't imagine that stepping on a copper pipe can cause that much harm. one would need a hammer to accomplish that.

what you could do is get some "Armaflex" insulation tape, cut insulation at various point and feel any temperature difference (if access is possible) and use tape to reinsulate where you cut open. i don't envy you for this job

but before crawling around in the ceiling remove casing of inside unit and measure temperatures of both pressure and suction pipe (a rather easy task because the two pipes are not joined). if you don't measure a big difference the problem is the evaporator.

question:

At the indoor unit they measure 16 degree and after heaving the aircon running on it's maximum power for an hour ande a half the temperature in the room is 24.7 degree.

where at the indoor unit did they measure 16º? pipe or blow-out air temperature?

[jbrain]

Time to get on the ceiling myself I guess

problem is that the pipes are insulated and i can't imagine that stepping on a copper pipe can cause that much harm. one would need a hammer to accomplish that.

what you could do is get some "Armaflex" insulation tape, cut insulation at various point and feel any temperature difference (if access is possible) and use tape to reinsulate where you cut open. i don't envy you for this job

but before crawling around in the ceiling remove casing of inside unit and measure temperatures of both pressure and suction pipe (a rather easy task because the two pipes are not joined). if you don't measure a big difference the problem is the evaporator.

question:

At the indoor unit they measure 16 degree and after heaving the aircon running on it's maximum power for an hour ande a half the temperature in the room is 24.7 degree.

where at the indoor unit did they measure 16º? pipe or blow-out air temperature?

They measured 16 degree blow out temperature, which is very high compared to 2 months ago when I still measured 7-8 degree, and the identical aircon in the other room still does 7-8 degree.I will ask them tomorrow to measure the pressure and suction pipe temperature.

Update : I went back to the service center again today and however they were confident that there was nothing wrong with the aircon, after pointing out some facts to them they agreed that there must be something wrong. They will come back tomorrow to check some more things that they " forgot " . They now think there may be something wrong with the pump in the outdoor unit, so that it doesn't give enough pressure.

Now here comes the snake in the grass. I was always told that the indoor unit has 1 year warranty and the outdoor unit 5 year warranty. The truth now is that from that outdoor unit only the compressor carries 5 year warranty and all the other parts inside that unit, inverter motor-pump-fan and what else is inside has only 1 year.

I'm not an aircon expert, but let me make a wild guess, the compressor is the only part that very rarely breaks.

So be aware when you buy an aircon from this brand.

[jbrain]

Surprised any brand air con these days has only a 1 year compressor warranty...standard is 3/5 for indoor unit and compressor and some even have 5/5 warranties. Especially unfortunate from a premium priced brand like "D."

I've been happy with my LG Inverter V aircon in one room the past 3 years and plan to go get another one for another room today.

I always fit LG invertor V aircons as well, good machine.

I actually have an LG invertor V aircon in my office, which I never switch on, and I had a problem that it always gives a " plop " in the indoor unit while non active.

The LG technicians came over and also heard the plop which originated in the PCB unit, so they made some modification in the PCB unit, which didn't make any difference. They came back and replaced the whole PCB unit, again without positive result.

They came once again and replaced the complete indoor unit with a new one.

I now cut off the power to the aircon because it still has that plop.

[JohnnyQuid]

I posted some time ago already that I had some issues with an inverter aircon from the famous D..... brand that didn't function the way it should.

 

So a few weeks ago I had a random technician come around to clean and top up 2 identical aircons installed in the bedrooms in the hope that would clear the issues, but that wasn't the case.

 

So I started checking. Both aircons are 12000 Btu inverter aircons from the same brand.One is installed in a 22 Sqm room and functions perfect ( let's call this aircon 1) , and the other one is installed in a 15 sqm room and function not good. Both aircons are 20 months old.

 

I measure the temperature at the indoor unit from Aircon 1 with setting 18 degrees on the remote and after 10 minutes it reads 1 degree with the blower on low then goes up to 7 probably to prevent freezing and 11 degrees with the blower on high.

 

The second one measures 14 degree on low and 17 degrees on high withh he same settings . So I think it;s clear there is something wrong.

 

I travel to the companies service center and explain my problem. They tell me that the indoor unit has 1 year warranty and the compressor 5 year. However if the compressor has to be replaced it cost me 3000 Baht anyway because labor and materials used are not covered

 

To check the aircon cost 428 Baht, which I have no problem with, so an appointment is made for this afternoon.

 

So 2 technicians arrive and start to check. refrigerant is sufficient as are power and current. At the tube leaving at the outdoor unit they measure 11 degree, but after running for about an hour that decrease to 7 degree.

 

At the indoor unit they measure 16 degree and after heaving the aircon running on it's maximum power for an hour ande a half the temperature in the room is 24.7 degree.I think at that point one can understand that the temperature will not get any lower

 

As I said the room is 15sqm, has 25 cm cavity walls, 6" insulation on the ceiling and 2 rather small pvc windows with insulated glass and it had been raining all afternoon

 

Yet the technicians complete their inspection and declare everything normal

 

I point out the measurements I make in the other room with the identical unit, but they say because it's a bigger room the aircon blows colder.

 

When I say that if I open the doors and the windows from the smaller room I would have a room of unlimited acreage and then the aircon should blow even cooler, they don't have an answer.

 

On my question why after running aircon on maximum power for 1.5 hour they can't get a 15sqm room with ambient temperature of 29 degree below 24.7 degree they also don't have an answer.

 

Nothing wrong sir, of course as soon as the warranty has expired they will find the problem, not ?>

 

So far my rant. I guess the 27.000 Baht + installation cost i spend 20 months ago was a good investment.

 

My next aircon wil  definitely not be from the D.....  brand.

Being a nearly ten year employee of the D brand im surprised, sorry and disapointed by this outcome for you. I'll be at head office next week and if you would like me to take this up with them then pm me your details and i will have them look into it and the techs who came out to check your unit.

[raro]

I'm looking for an inverter aircon myself. Checked the aircon shop at Nongprue intersection and they gave me the well researched answer that they are "more expensive".

Can anyone recommend an aircon shop that carries such aircons AND is able to install AND maintain them?

I have been recommended the D brand as the best since sliced bread. Now I read here that they are probably not that good. Any brand recommendations? The aircon is for a warehouse so I don't really care about noise etc.

[raro]

Being a nearly ten year employee of the D brand im surprised, sorry and disapointed by this outcome for you. I'll be at head office next week and if you would like me to take this up with them then pm me your details and i will have them look into it and the techs who came out to check your unit.

yeah...we would like to hear about the outcome indeed! This is what community fora are there for!

[jbrain]

I posted some time ago already that I had some issues with an inverter aircon from the famous D..... brand that didn't function the way it should.

So a few weeks ago I had a random technician come around to clean and top up 2 identical aircons installed in the bedrooms in the hope that would clear the issues, but that wasn't the case.

So I started checking. Both aircons are 12000 Btu inverter aircons from the same brand.One is installed in a 22 Sqm room and functions perfect ( let's call this aircon 1) , and the other one is installed in a 15 sqm room and function not good. Both aircons are 20 months old.

I measure the temperature at the indoor unit from Aircon 1 with setting 18 degrees on the remote and after 10 minutes it reads 1 degree with the blower on low then goes up to 7 probably to prevent freezing and 11 degrees with the blower on high.

The second one measures 14 degree on low and 17 degrees on high withh he same settings . So I think it;s clear there is something wrong.

I travel to the companies service center and explain my problem. They tell me that the indoor unit has 1 year warranty and the compressor 5 year. However if the compressor has to be replaced it cost me 3000 Baht anyway because labor and materials used are not covered

To check the aircon cost 428 Baht, which I have no problem with, so an appointment is made for this afternoon.

So 2 technicians arrive and start to check. refrigerant is sufficient as are power and current. At the tube leaving at the outdoor unit they measure 11 degree, but after running for about an hour that decrease to 7 degree.

At the indoor unit they measure 16 degree and after heaving the aircon running on it's maximum power for an hour ande a half the temperature in the room is 24.7 degree.I think at that point one can understand that the temperature will not get any lower

As I said the room is 15sqm, has 25 cm cavity walls, 6" insulation on the ceiling and 2 rather small pvc windows with insulated glass and it had been raining all afternoon

Yet the technicians complete their inspection and declare everything normal

I point out the measurements I make in the other room with the identical unit, but they say because it's a bigger room the aircon blows colder.

When I say that if I open the doors and the windows from the smaller room I would have a room of unlimited acreage and then the aircon should blow even cooler, they don't have an answer.

On my question why after running aircon on maximum power for 1.5 hour they can't get a 15sqm room with ambient temperature of 29 degree below 24.7 degree they also don't have an answer.

Nothing wrong sir, of course as soon as the warranty has expired they will find the problem, not ?>

So far my rant. I guess the 27.000 Baht + installation cost i spend 20 months ago was a good investment.

My next aircon wil definitely not be from the D..... brand.

Being a nearly ten year employee of the D brand im surprised, sorry and disapointed by this outcome for you. I'll be at head office next week and if you would like me to take this up with them then pm me your details and i will have them look into it and the techs who came out to check your unit.

Thank you for your concern. PM sent.

[jbrain]

I'm looking for an inverter aircon myself. Checked the aircon shop at Nongprue intersection and they gave me the well researched answer that they are "more expensive".

Can anyone recommend an aircon shop that carries such aircons AND is able to install AND maintain them?

I have been recommended the D brand as the best since sliced bread. Now I read here that they are probably not that good. Any brand recommendations? The aircon is for a warehouse so I don't really care about noise etc.

I bought my aircons from the wholesale that supplies all the parts to the technicians, since they were by far the cheapest at that time. They carry all brands and are located 3 shop houses before Fascino pharmacy on Nua road, next to Giffarine.

They don't do any install themselves, but since they supply the parts to almost every aircon installer in the Pattaya area, they can advise you in that.

[jbrain]

Hi, here we are with the update.

This afternoon D..... came around with 5 technicians, they must have hired a bus I guess

So they start checking again with about the similar results as the other day.

So they decide the problem is the sensor in the indoor unit.However instead of changing the sensor only, they change the whole PCB. On my question as why the don't replace only the sensor they reply that it comes complete as one piece, nevertheless I notice they disconnect the small board with the sensor from the rest of the PCB at one point.

After they have changed the PCB they test again and the aircon get's the desired temperature, so it seems that indeed the sensor was the trouble maker, so mission accomplished.

They present me with a bill of 3540 Baht for the parts, labor and maybe the test cost but I'm not sure if the latter was included. Since I hadn't expected that they would change any parts right away, I tell them that I will clear the bill after the weekend, which wasn't a valid possibility for them.

I then suggest that they replace the old PCB again and that they can come back after the weekend to which they agree.

Now here comes the funny part.

After they inserted the original PCB again and have left I turn on the aircon with still my digital thermometer attached. I'm surprised to discover that the unit now works as expected and after about 15 minutes measures the same temperature as with the new PCB.I have let it run for an hour and the indoor unit blows 7.6 degree where it previously wouldn't get below 15 degree.

So there was nothing wrong with the sensor or whatever, but it seems that there must have been a bad connection on the main board or in the sensor. At least that is my opinion, which may differ from yours.

Is it possible that the sensor functions sometimes and sometimes errors, so that maybe in a few weeks the same problem will return, or do you think the cause of the problem was something else?

Since I saw that they can detach the small board with the sensor from the rest of the PCB, why can't they just replace the sensor, which of course would cost much less.

[Naam]

some of the reported facts do not match JBrain, e.g. even the blow-out temp of 16º should cool down the room lower than 24.7º after one hour run, except if a heat source indoor or heavy heat transmission from outdoors exist.

i have also strong doubts that the reported 7.6º blow-out temp is correct assuming the intake air is higher than 25ºC. could it be that the 7.6º were measured by touching the evaporator fins with the sensor of the temp gauge? because that would be normal.

[Naam]

I'm looking for an inverter aircon myself. Checked the aircon shop at Nongprue intersection and they gave me the well researched answer that they are "more expensive".

Can anyone recommend an aircon shop that carries such aircons AND is able to install AND maintain them?

I have been recommended the D brand as the best since sliced bread. Now I read here that they are probably not that good. Any brand recommendations? The aircon is for a warehouse so I don't really care about noise etc.

if the aircon is for a warehouse with most probably a continous even demand of cooling capacity why would you select an inverter unit?

inverters work only economically if the demand varies a lot. if that is not the case an inverter equals wasted initial investment and with time exponentially higher repair cost.

[OMGImInPattaya]

Numchai are excellent, but only stock the split wall mount style, nothing bigger.

I've always had good luck with them and its nice they have their own service dept. too.

They just installed a small LG Inverter V for me yesterday. B 18.9k for the 9000 BTU model, which includes 2 free cleaning coupons.

[raro]

I'm looking for an inverter aircon myself. Checked the aircon shop at Nongprue intersection and they gave me the well researched answer that they are "more expensive".

Can anyone recommend an aircon shop that carries such aircons AND is able to install AND maintain them?

I have been recommended the D brand as the best since sliced bread. Now I read here that they are probably not that good. Any brand recommendations? The aircon is for a warehouse so I don't really care about noise etc.

if the aircon is for a warehouse with most probably a continous even demand of cooling capacity why would you select an inverter unit?

inverters work only economically if the demand varies a lot. if that is not the case an inverter equals wasted initial investment and with time exponentially higher repair cost.

interesting! I have been told that inverters are perfect for an even demand of cooling capacity...

[jbrain]

some of the reported facts do not match JBrain, e.g. even the blow-out temp of 16º should cool down the room lower than 24.7º after one hour run, except if a heat source indoor or heavy heat transmission from outdoors exist.

i have also strong doubts that the reported 7.6º blow-out temp is correct assuming the intake air is higher than 25ºC. could it be that the 7.6º were measured by touching the evaporator fins with the sensor of the temp gauge? because that would be normal.

All temperatures were measured by two digital thermometers, one of my own that has his outdoor sensor attached to the outlet of the indoor unit, and the other one a handheld thermometer identical to this one provided by the technicians and held in front of the blower ( not inside the blower) At all times both thermometers measured a temperature with a difference between the two of less than 0,5 degree.

The room temperature was measured by a third digital thermometer which was placed 3½ meter away from the indoor unit and which has a proven accuracy.

We compared now the measurements with the other identical aircon in the bigger room, using the same methods, and they were similar in that the temperature reached about 1 degree lower which I suppose is because the distance to the compressor is about 3 meter less.

Edited September 15, 2013 by jbrain

[jbrain]

Too late to edit, but to avert confusion I should add that the 7,6 degree was the temperature I measured, after the technicians had left and with the original PCB installed, and with the aircon running for 1 hour.

At the time the that the new PCB was installed, the technicians measured 8,5 degree but with the aircon running for less than half an hour.

Probably if they had the time to run for a full hour the temperature would have been comparable to my measurements.Fact is that the other aircon measured below 8 degrees after only half hour running.

[jbrain]

even the blow-out temp of 16º should cool down the room lower than 24.7º after one hour run, except if a heat source indoor or heavy heat transmission from outdoors exist.

I agree that a 16 degree temperature would be sufficient to maintain a 24 degree room temperature, but I think the purpose of an inverter aircon is that it starts at a low temperature and higher fan speed to get to the desired room temperature as quickly as possible, then adjust itself to maintain that temperature.

With a 16 degree blow out temperature you could reach the desired temperature over time depending on he fan setting.

The test was conducted with the aircon set to 18 degree ( lowest possible) and the fan speed at it's lowest setting as this would measure the lowest temperature right at the blower.

OI course in exchange, the lowest fan speed will also require the longest time to get a room to the desired temperature.

I checked over night with the setting on 26 degree and fan speed on auto, and at the start the temperature at the blower would measure around 12 degree with the fan audible at a higher speed, but in the morning the temperature would fluctuate between 18 and 24 degree while you could barely hear the fan , while the room temperature would swing between 26 and 27.2 degree before the compressor kicked in.

Edited September 15, 2013 by jbrain

[Naam]

I'm looking for an inverter aircon myself. Checked the aircon shop at Nongprue intersection and they gave me the well researched answer that they are "more expensive".

Can anyone recommend an aircon shop that carries such aircons AND is able to install AND maintain them?

I have been recommended the D brand as the best since sliced bread. Now I read here that they are probably not that good. Any brand recommendations? The aircon is for a warehouse so I don't really care about noise etc.

if the aircon is for a warehouse with most probably a continous even demand of cooling capacity why would you select an inverter unit?

inverters work only economically if the demand varies a lot. if that is not the case an inverter equals wasted initial investment and with time exponentially higher repair cost.

interesting! I have been told that inverters are perfect for an even demand of cooling capacity...

information from the chap who spread the rumour that bar fines in Walking Street have been abolished?

if an even demand for cooling capacity exists an inverter unit won't save a single Satang on energy cost.

by the way, if my assumption is correct that you need cooling for bottles with a certain tasty liquid content make sure that the unit is not over dimensioned in order to achieve a smooth continous run without too many on/off.

[Naam]

Too late to edit, but to avert confusion I should add that the 7,6 degree was the temperature I measured, after the technicians had left and with the original PCB installed, and with the aircon running for 1 hour.

At the time the that the new PCB was installed, the technicians measured 8,5 degree but with the aircon running for less than half an hour.

Probably if they had the time to run for a full hour the temperature would have been comparable to my measurements.Fact is that the other aircon measured below 8 degrees after only half hour running.

blow-out temperature depends on the air intake temperature. only if the latter is identical you can compare two units.

[jbrain]

Too late to edit, but to avert confusion I should add that the 7,6 degree was the temperature I measured, after the technicians had left and with the original PCB installed, and with the aircon running for 1 hour.

At the time the that the new PCB was installed, the technicians measured 8,5 degree but with the aircon running for less than half an hour.

Probably if they had the time to run for a full hour the temperature would have been comparable to my measurements.Fact is that the other aircon measured below 8 degrees after only half hour running.

blow-out temperature depends on the air intake temperature. only if the latter is identical you can compare two units.

When 2 aircon compressors are installed next to each other, it would be fair to assume that they have identical air intake.

I guess it's also fair to assume that a 11 meter tube might have a loss of 0,5 degree compared with a 8 meter long tubing.

[Naam]

Too late to edit, but to avert confusion I should add that the 7,6 degree was the temperature I measured, after the technicians had left and with the original PCB installed, and with the aircon running for 1 hour.

At the time the that the new PCB was installed, the technicians measured 8,5 degree but with the aircon running for less than half an hour.

Probably if they had the time to run for a full hour the temperature would have been comparable to my measurements.Fact is that the other aircon measured below 8 degrees after only half hour running.

blow-out temperature depends on the air intake temperature. only if the latter is identical you can compare two units.

When 2 aircon compressors are installed next to each other, it would be fair to assume that they have identical air intake.

I guess it's also fair to assume that a 11 meter tube might have a loss of 0,5 degree compared with a 8 meter long tubing.

confusion²! i am not talking about compressors but indoor units. remember i mentioned evaporator fins? now it turns out that you are talking about outdoor units.

but for what it's worth... even the temperature after the expansion valve at the outdoor unit depends on the temperature of the rom where the indoor unit is installed because the returning gaseous refrigerant which is liquified by condenser and compressor has a different temperature and therefore cause a different "delta t" after the expansion valve (assuming that the two indoor units are located in different rooms.

let's start all over again! clarify where did you measure what temperature? indoors or outdoors? air temperature? pressure or suction pipe temperature?

[jbrain]

Too late to edit, but to avert confusion I should add that the 7,6 degree was the temperature I measured, after the technicians had left and with the original PCB installed, and with the aircon running for 1 hour.

At the time the that the new PCB was installed, the technicians measured 8,5 degree but with the aircon running for less than half an hour.

Probably if they had the time to run for a full hour the temperature would have been comparable to my measurements.Fact is that the other aircon measured below 8 degrees after only half hour running.

blow-out temperature depends on the air intake temperature. only if the latter is identical you can compare two units.

When 2 aircon compressors are installed next to each other, it would be fair to assume that they have identical air intake.

I guess it's also fair to assume that a 11 meter tube might have a loss of 0,5 degree compared with a 8 meter long tubing.

confusion²! i am not talking about compressors but indoor units. remember i mentioned evaporator fins? now it turns out that you are talking about outdoor units.

but for what it's worth... even the temperature after the expansion valve at the outdoor unit depends on the temperature of the rom where the indoor unit is installed because the returning gaseous refrigerant which is liquified by condenser and compressor has a different temperature and therefore cause a different "delta t" after the expansion valve (assuming that the two indoor units are located in different rooms.

let's start all over again! clarify where did you measure what temperature? indoors or outdoors? air temperature? pressure or suction pipe temperature?

To make it easy. All temperatures measurements mentioned in previous posts of me, which read below 20 degrees, were done in front of the air outlet of a indoor unit.

All measurements mentioned that read above 20 degrees concern room temperatures.

My understanding was that the air intake took place at the outdoor unit, however in a house with rooms next to each other I would think that the ambient temperature is close in both rooms.

The technicians always measured the temperature above the indoor unit as well.I guess that must be the air inlet of the indoor unit then.

In the respective 3 tests the temperatures were as followed ( Temp. intake indoor unit / Temp. in front of indoor unit outlet) 26,3/13,3 - 27,8/14,5 and 25,5/8,5 .With the last test having the lowest intake temp because the aircon had been running for some time prior already.

Edited September 15, 2013 by jbrain

[Litlos]

Having spent 8 years learning electronics at night school to work out that 50% of electrical/electronic faults are push on connectors yes I can believe that the sensor unit now works. This is called "reseating connectors" when writing out service reports.

These style of domestic air conditioners will probably not have an expansion valve, to expensive. They will have a length of capillary (small bore) tube to basically do the same thing a lot cheaper.

When taking readings for temperature etc you have to ensure the compressor is running as well as the fan of the external unit, the compressor will give the buzzing sound and the fan is pretty obvious with the airflow. This working all is good and things are happening normally. Leave the air conditioner running for about 5 minutes then measure the air temperatures at the air inlet and outlet for the internal unit. About 10 to 13 degc difference between the two temperatures is good.

Have fun with the bill on this, but suggesting they got it wrong the first couple of times would be accurate. If now running you are in a good position to say the service was rubbish first time round.

Cheers

[jbrain]

Having spent 8 years learning electronics at night school to work out that 50% of electrical/electronic faults are push on connectors yes I can believe that the sensor unit now works. This is called "reseating connectors" when writing out service reports.

These style of domestic air conditioners will probably not have an expansion valve, to expensive. They will have a length of capillary (small bore) tube to basically do the same thing a lot cheaper.

When taking readings for temperature etc you have to ensure the compressor is running as well as the fan of the external unit, the compressor will give the buzzing sound and the fan is pretty obvious with the airflow. This working all is good and things are happening normally. Leave the air conditioner running for about 5 minutes then measure the air temperatures at the air inlet and outlet for the internal unit. About 10 to 13 degc difference between the two temperatures is good.

Have fun with the bill on this, but suggesting they got it wrong the first couple of times would be accurate. If now running you are in a good position to say the service was rubbish first time round.

Cheers

I don't think they did any wrong measurements in any of the tests, since at all times two thermometers were used which gave similar readings.Also the aircon was always set to 18 degrees and running for more than an hour, while the temperature was monitored constantly .

They tried to fool me when I asked to compare the temperatures with the aircon in the other room. They set the temperature of that unit to 27 degrees because that indoor unit would blow a higher temperature as a unit that is set to 18 degree.

Even when I discovered the high temp setting and adjusted it to the same low temp setting as the faulty one, they reset it again behind my back. When I made them clear in a determinative way that I wanted to compare apples with apples, they left the setting at 18 degree.

I guess this was done in an attempt to save face because they denied there was anything wrong.

Your theory of the re-seating sensor connectors is a plausible explanation why the aircon started working properly after the PCB was removed and then refitted again.

[Naam]

These style of domestic air conditioners will probably not have an expansion valve, to expensive. They will have a length of capillary (small bore) tube to basically do the same thing a lot cheaper.

i was told all "D" brand inverter aircons inject via expansion valve not via capillary tube but have no idea whether this information is correct. but whatever, expansion valve or capillary tube, it does not change any of the discussed facts or results.