Daikin-bs box problem?

[dingle87]

Hi people,
This is my first post, so go easy, lol.

my problem is with a Daikin vrv system RSEYG10(3pipe). There are 6 indoors connected. All units are calling for heat, and have there own individual bs box. 4 out of the 6 units are working fine. systems pressures ok. 2 indoor units seem to be underperforming.

when ive checked the pipe temps at the bs boxs, (touchy,feely) the discharge temperature seems to be ok. where as, on the outlet side of the box just feels luke warm. This is happening with 2 out of 6 bs boxs. There is a 240v feed to the coil, as i have checked at the bs box pcb. Possilbe sign of a blockage? solenoid valve energised but not moving?.....They also seem quite noisy (?)


Today, i have recovered all refrigerant from the system to have a closer look in the box. It was impossible to look in it in situe, so i had to take it down.

Daikin have told me these bs box's are now obsolete(?)

Im going back on site in the morning to have another look, Try to free valve,do some head scratching,etc.

Thanks in advance,
danny.

[aeb200]

do the units work in cooling??
have you checked the LEV valves on indoor units??
The LEV may be stuck shut.
to reset unplug from indoor board carefully unclip the blue and yellow cables from the plug
(using a small terminal or watchmakers screwdriver push down on springy catch (back of plug) then push forward (releases cable) then pull back wire out of plug)
swap the cables over (blu and yellow)
then plug back into indoor unit (you'll hear valve pulse open) plug and unplug a couple of times then swap wires back to original position.
This proceedure will reset valve and will hopefully cure problem - if not unscrew valve head from body (youll hear a rush of refrigerant into coil) if this works replace valve (driver head may seized)

[Iceman1956]

Have you checked the system capacity. Most installations have 20 - 30% diversity built into them. I have found that if the system has too much diversity when all units are calling for heating/cooling at 100%, some will under perform. Try switching of one or two units that are operating OK, and see if the under performing units start to operate correctly. If they do then your condensing unit may have been under sized to cope with maximum load of all units. Also check refrigerant charge, if this is not correct you can have similar problems.

[frank]

The first thing to check would be 'How many indoor units can the out door unit see'

If it's only seeing 4 out of the 6 then the problematic 2 no. would not have any control.

Do a full restart and go through the basics before blaming a BS box.