FTKS25DVM problem

[happily1986]

A particular FCU is having cooling issue. It is on a system 3 grid and the unit will intermittently blow air which is not cold. I determine this by measuring the temperature of the air exiting the FCU. It should be around 16 to 17 degrees C but it is measuring around 20ish.

This issue can be reset by switching off and switching on the FCU again. It happens when all 3 FCUs are running and also when only 2 FCUs are running.

When using the remote to check for a possible error code, I determined the long beep to be for 00. However searching online yields nothing for this error code. What gives for this error code? Is it even a valid one?

[nick2ono]

if you got 00 it means the is no alarm detected by the pcb of fcu.

[happily1986]

if you got 00 it means the is no alarm detected by the pcb of fcu.

Lol. I just couldn't find this up on any literature referencing the daikin fault codes. I have always wanted to ask though; do all FCUs on a multiple FCU mini split system share the same ***** gas loop or does each FCU have a dedicated mini loop with the evaporator core and compressor?

I am beginning to wonder whether I could be suffering from insufficient refrigerant gas but the other FCUs seem to be substantially better off in cooling.

[still learning]

Lol. I just couldn't find this up on any literature referencing the daikin fault codes. I have always wanted to ask though; do all FCUs on a multiple FCU mini split system share the same ***** gas loop or does each FCU have a dedicated mini loop with the evaporator core and compressor?

I am beginning to wonder whether I could be suffering from insufficient refrigerant gas but the other FCUs seem to be substantially better off in cooling.

Hi, do you know the. Model and size of your outdoor unit?
And the amount of pipework on your system?
Is it the one the longest run away from the out door that. Does not perform?

[happily1986]

I believe the outdoor unit is the RKS25G. The room is the furthest away from the compressor and the ductwork is about 12m give or take from the compressor unit.

A few days ago while the FCU is in operation, i tried lifting up the front louver and the air filter and felt the heat exchanger coil. I realised that the frontal portion of the heat exchanger was not cold at all. However the sides of the A tower coil as well as the rear was cold.

What does this means? Does this means that there is something wrong with the A tower coil or the refrigerant is not enough? I tried running the FCU alone with the other 2 FCUs shut off and cooling was satisfactorily.

I am worried that recharging the R410A is just an interim solution. Is this normal for a system 3 that has been installed since 2008?

[frank]

The outdoor model is a cooling only unit rated at 2.5kw total cooling duty. How can you have 3x indoor fan coils attached to it?

[happily1986]

The outdoor model is a cooling only unit rated at 2.5kw total cooling duty. How can you have 3x indoor fan coils attached to it?

My bad it should be the 3MKS50FSG.

[still learning]

Hi. I was looking at the technical information, that was on the Internet. For your system .
and see that. You have a allowance for 50 meters of copper pipe work for your three indoor units in total .
You have. One unit at twelve meters , and if you had 12 meters each for the other two,gives you ,a possible of 36 meters in total which looks to be within your limits.
as you have no faults in you controller.
it could well have a tiny leak from a flared connection , or a indoor coil that has failed .
I would check your flare connections, both indoor and out door and. Look for any signs of oil mist .
i took the cover off a dakin wall mount the other day to get to the condensate pump sensor , and found oil mist all around the inside. This unit also, showed no faults in it controller,yet is still cooling to a fashion.
after eight years you could be a little down on gas if you have a tiny leak.
if you had the gas reclaimed and weighed you will know, then run a pressure test and check all connections any any brazes in pipe work if possible.
good luck.

[Slim R410a]

Possibly a fault with the EEV? I've had this before on a Daikin, no fault codes shown.

[happily1986]

Possibly a fault with the EEV? I've had this before on a Daikin, no fault codes shown.

Do you mind telling me where is the location of the EEV? Is there a isolated EEV for each Multisplit FCU. My FCU has the longest line run from the compressor.

[Slim R410a]

Do you mind telling me where is the location of the EEV? Is there a isolated EEV for each Multisplit FCU. My FCU has the longest line run from the compressor.

Yes there will be an EEV before each liquid connection on the outdoor unit. You will have to remove the main front cover to access these.
Try swapping the EEV valve head with another room see if it makes a difference? You can swap the EEV heads without removing refrigerant.
Also try swapping the liquid pipe thermistor (located just after the EEV) with another room?

[happily1986]

I have been monitoring this FCU to look for some more visible tell tale sign of deviating behavior and I am able to determine that whenever the FCU does not produce sufficiently cold air, the frontal bottom half of the A cooling coil is not cold at all (only the top half is cold). Intermittently when the FCU is so called working properly, I don't see such uneven cooling on the coil (top and bottom wise)

Does this still point to an intermittent EEV issue? And how do we check or differentiate whether it is an indoor or outdoor EEV issue then?

[back2space]

I have been monitoring this FCU to look for some more visible tell tale sign of deviating behavior and I am able to determine that whenever the FCU does not produce sufficiently cold air, the frontal bottom half of the A cooling coil is not cold at all (only the top half is cold). Intermittently when the FCU is so called working properly, I don't see such uneven cooling on the coil (top and bottom wise)

Does this still point to an intermittent EEV issue? And how do we check or differentiate whether it is an indoor or outdoor EEV issue then?

Either way 16/17C air off is too low on a R410A system air off would be around 10/11C.

[Slim R410a]

Either way 16/17C air off is too low on a R410A system air off would be around 10/11C.

Depends what your air on temperature is.. he is in Singapore

[Slim R410a]

http://www.refrigeration-engineer.co...ult&highlight=

I had a similar issue, 3.5 years ago now but from memory changed both EEV valves.