Daikin FDYQ200PV1 temperature variation

[Mick301]

I have a Daikin FDYQ200PV1 running from a Daikin BRC230Z4 zone controller. Temp sensing is from return air in the fan coil. No other remote sensors are installed. Problem is if I set the temp to 23c (cooling) it will drop to that temp but if outdoor temp gets very high as it did last week (39c) the inside temp continued to drop down to about 20c and I had to set the temp to 26c to get it back up around 23c. Situation appears reversed at night. Can have it set on 23c and as night progresses eg outside temp drops, the inside temp rises past the 23c setpoint by anything upto 3 degrees. Seems as though outside unit is sensing outside temp and setting trends or something but it is definatley over compensating. Any field settings that can be altered or advice would be appreciated. I'm also keen to get a full manual for this unit ?

[back2space]

Are you sure warmer ar isnt getting pulled into the return air grille from the ceiling void etc?

[VRVIII]

I have a Daikin FDYQ200PV1 running from a Daikin BRC230Z4 zone controller. Temp sensing is from return air in the fan coil. No other remote sensors are installed. Problem is if I set the temp to 23c (cooling) it will drop to that temp but if outdoor temp gets very high as it did last week (39c) the inside temp continued to drop down to about 20c and I had to set the temp to 26c to get it back up around 23c. Situation appears reversed at night. Can have it set on 23c and as night progresses eg outside temp drops, the inside temp rises past the 23c setpoint by anything upto 3 degrees. Seems as though outside unit is sensing outside temp and setting trends or something but it is definatley over compensating. Any field settings that can be altered or advice would be appreciated. I'm also keen to get a full manual for this unit ?

Where is the indoor unit pulling it's return air from?
(Ducted return from room/from ceiling void)
Is there any fresh air ducted to the unit?

[brunstar]

mick,
In relation to your indoor unit the system is most definately being influenced by the temperature in your roof space.
If the outdoor was 40 degrees i would think your roof space would be about 85 degrees during the day.
What you will need to do is get your installer back to seal the return air plenum or install a remote sensor.
The other thing that they may have done is installed a fresh air duct to the return air, this will keep the system running if the air onto the coil is at 40 degrees.

[Mick301]

return air is through 2 return air-boxes located opposite ends of reasonably long hall. There is no external fresh air entering the system. All above ceiling height (in cavity) is a closed circuit. Its a recent install & I took quite an interest in what they did. All ducts & return air boxes are well sealed. I thought I would try switching the temp sensor from the fan coil to the wall controller to see if that altered the situation but the field setting combination required won't allow me to. Only temp sensor it will allow (or shows as being available) is the fan coil. The controller, BRC230Z4 appears to be used mainly in Australia & NZ. I can't get a lot of information on it, only basic operating instructions. So a little lost at what to do ?

[VRVIII]

return air is through 2 return air-boxes located opposite ends of reasonably long hall. There is no external fresh air entering the system. All above ceiling height (in cavity) is a closed circuit. Its a recent install & I took quite an interest in what they did. All ducts & return air boxes are well sealed. I thought I would try switching the temp sensor from the fan coil to the wall controller to see if that altered the situation but the field setting combination required won't allow me to. Only temp sensor it will allow (or shows as being available) is the fan coil. The controller, BRC230Z4 appears to be used mainly in Australia & NZ. I can't get a lot of information on it, only basic operating instructions. So a little lost at what to do ?

Hi Mike,

I’m not familiar with the BRC230Z4 controller you have, these are not available in UK.
Is there a thermistor inside this controller?

The field settings used on a BRC1D527 to select which sensor is used for thermostat control are;
10-2-01 = Combination of both return air & remote sensor
10-2-02 = Return air sensor only
10-2-03 = Remote sensor only (not applicable for all indoor units)

I would suggest you check the unit return air temp in code 41 then compare this to your actual room temp, this would allow you to verify if the sensor is being influenced or possibly out of calibration.

Is there a problem with installing a KRCS01 wall sensor? This would also help eliminate temp difference due to stratification

[brunstar]

Hi there, In relation to your BRC230Z4, i would get your installer back.
This is a 4 zone multi controller, if i remember correctly you can sense from different zones with that controller if remote sensors are installed.
For example when you have the living room only on it will sense from that area.
This is not necessary but just like VRVIII said you may want to install an additional remote sensor.

Was your hall way dropping to 23 degrees also as there is no conditioned air being supplied directly to this area so with doors closed within the house the flow from the conditioned space to the return air in the hall would be a fairly different temperature.

[Mick301]

Thanks for the replies. Yes the controller is a multi zone type. I will get the installer back (I have a minor problem with too much air flow to one bedroom) & ask some questions. I would like to find some more technical info (field settings etc) for this controller but info is limited on the net so far. I think the controller maybe a reasonably new release. I also think a couple of remote sensors might be a good idea...does anyone know if this controller has a thermistor?

[Mick301]

To answer your question Brunstar, so far I haven't zoned off any areas so the whole house is being conditioned. The hallway air temp would be similar to the rest of the house. I'm beginning to think more & more it is a sensor problem rather than hot air getting into the return or other mechanical influences or problems. I think I need to get a better scope or spread of sensor information for the unit to process rather than just relying on the return air at the fan coil...again any info anyone has on this unit & the complete system would be helpfull. VRVIII you gave me some PDF references in my other post with regard to noise reduction settings. Is this part of a full manual that you have access to? I would be interested in the full manual if its available ?

[alloffs1]

I have RY160LUY1 outdoor motor with a BRC1C61 controller. The problem I have is that at the moment the unit never shuts down because it is using the sensor in the return air vent in the roof. I was wondering if anyone knows how to change the setting so that the controller on the wall senses the temperature instead. Thank you.

[brunstar]

I have RY160LUY1 outdoor motor with a BRC1C61 controller. The problem I have is that at the moment the unit never shuts down because it is using the sensor in the return air vent in the roof. I was wondering if anyone knows how to change the setting so that the controller on the wall senses the temperature instead. Thank you.

You will find that you can change some field settings but you need to be careful.
The indoor unit that you have installed will not be able to sense from the remote controller only so you will need to purchase an additional remote sensor to plug into that indoor unit and install in the location at which you require your sensing to take place.
here are the field codes but it will not really help you as you will only be able to do an average of the two sensors.
10-2-01 = Combination of both return air & remote sensor
10-2-02 = Return air sensor only ( current Field setting)