Daikin probelms

[Reffnut]

I've been having some right problems with daikin vrv since this cold weather started, E4 faults (low pressure), JA (high discharge pressure) F3 (dicharge temp) all on different systems! Now today daikin told me today that they're units won't run below -5 ambient has anyone else heard this before?

Cheers lads

[james10]

yep, i got told this on the vrv3 course i also got told if you "keep the ambient sensor warm" it would run

[Reffnut]

Its not much good though really the amount of buildings now relying on these systems for their heating! That's the plan tomorrow warming up the air sensor! Do you know if it's just vrv3 or is it for all daikin?

[james10]

Its not much good though really the amount of buildings now relying on these systems for their heating! That's the plan tomorrow warming up the air sensor! Do you know if it's just vrv3 or is it for all daikin?
not just daikin i believe mitsi electric units have been known to just sit there doing nowt cause it's too cold i dont think heat pumps should be relied on as the only source of heating in the uk

[Roundflow]

The problem with using heat pumps as primary source heating in this weather is mainly down to building temps dropping too low overnight or over a weekend.
Typically if the indoor temp drops below approx 16 deg C the system will in essence start to over condense, evap temp drops, systems in defrost regularly and they struggle to recover.
Another issue is over diversity on VRF , as a rule never exceed 100% if a system is the primary heating source to be safe.

[El Padre]

I have experienced reduced performance from frequent defrosts etc. but if the unit is fully operational it should perform as per the design spec.

I think that you have something else wrong with your system, could be an insufficient charge, when was the system performance last verified?

Cheers

[VRVIII]

I've been having some right problems with daikin vrv since this cold weather started, E4 faults (low pressure), JA (high discharge pressure) F3 (dicharge temp) all on different systems! Now today daikin told me today that they're units won't run below -5 ambient has anyone else heard this before?

Cheers lads

That’s absolute rubbish a VRV system will operate in heating mode to -20 C as stated in the Daikin Technical Data Book, you will have a capacity drop of around 10% with a 130% connection ratio at -5 ambient and no errors should occur.

Obviously the systems will be operating flat out at an ambient of -5 which will in turn highlight any system problems.

There is defiantly a problem with your systems and would suggest you verify the refrigerant charge, pipe run length, correct size pipes have been installed and check for non condensables.
I would then check calibration of thermistors, pressure transducers and correct operation of outdoor expansion valves.

The JA (high discharge pressure) error you referred to is actually indicating that the high pressure transducer is out of range.

What is the full model number of these units?
Are the systems operating in heating mode or heat recovery?
Do you have even frost accumulation across outdoor heat exchangers?

[Reffnut]

The Systems with the JA and F3 faults IS VRV RSEYP10K7W1 407c 2002, heat recovery, this system kept throwing up these 2 faults i recovered the refrigerant and found system 11kg short of gas pressure tested found and repaired leak, recommissioned and charged with correct amount of gas, but when running the inverter compressor sounded very weird and after an hour of running system went into JA fault again, ive now programmed out the inverter on this system and system has ran since with no faults so i think thats on the way out!

The other system is vrv3 RXQ8P7W1B which has had a E4 fault this is the system the DAIKIN specifically told me wont run under -5 its cooling only and has 4 units which are in comms rooms 2 in each ive checked the charge on this system too which is fine had system working fine today with no issues but still no explanation for the client of whats caused the original E4 fault

Cheers for replys