Daikin vrv

[grovecoooling]

Hi Chaps

Im hoping someone out there can give me some much needed advice.

I have a system which comprises of 6 void indoor units on 1 outdoor unit, its a 3 pipe system with individual bs units.

In cooling mode all units work fine, but in heating 1 unit is not heating, its the nearest unit to the condenser, im convinced its not a gas charge issue.

At the bs unit the discharge pipe is hot but a bit cooler out of the bs unit to fan coil.
I spoke to daikin and carried out various checks and the strange thing was that the thermistor temp was 41 degrees, but def no heating from fan coil.
I think that there is a blockage in the bs box limiting refrigerant to fan coil, the problem i have is that being R407c Daikin do not do a replacement bs box but sell each solenoid component individually.
i could order these up and strip the unit down and fit, but now i have come away from the job (its a 3 hour journey) im thinking could it be as simple as the indoor unit thermistor faulty.
that would be ideal as i would not have to de gas system.

Please help;)

[install monkey]

whats the coil temp in cooling mode?

[grovecoooling]

whats the coil temp in cooling mode?

thanks for the reply

I never checked but its cooling well, about 9 degrees at the supply grills

[frank]

In heating mode, the fan is held off by the coil thermister until it exceeds 34C so as to prevent cold draughts. If your sensor is reading wrong then it will not allow heating.

This doesn't happen in cooling mode.

Attached PDF gives details.

Check the resistance of your sensor or swap it with an adjacent unit before you start on the BS Box ;)