View Full Version : Mitsubishi VRF

RU Cooling
29-10-2013, 09:30 AM
Hi I'm new so not sure if I'm posting this in right section.
I have just turn't on a new system I installed on a 17 fan coil system and a the units keep displaying heat standby and then when they heat they throw out very little heat. It's a 300+400 condenser which has taken 48kg added R410a (calculated by Mitsubishi) + 20kg pre charge. Could it be short of gas still? I need to get this sorted asap as handover is tomorrow! If I run half I get some heat off but still not what it should be. Please help!!

29-10-2013, 10:39 AM
Have you had the crankcase heaters energised for the recommended length of time? If not, the system will run in protective limited output mode.

RU Cooling
29-10-2013, 11:32 AM
We had the issue after turning on 2 hours after power was on and is doing it now even though has been power on since Friday.

RU Cooling
29-10-2013, 11:43 AM
Please someone help!

Kev The Tool
29-10-2013, 12:22 PM
Hi Ryan,

Will the system run in test mode?

RU Cooling
29-10-2013, 01:01 PM
I put units on test through controller and they done the same thing so very little heat.

install monkey
29-10-2013, 08:52 PM
is the compressor ramping up, check on the outdoor pcb target freq,actual frequency - comfirm number of indoors connected- check all valves open- also pipe sensor values- all accessed via dipswitches

31-10-2013, 07:10 AM
Do you have any fresh air onto the indoor fan coils? If so is it pre-heated? Balanced? Are indoors in any kind of boxing? Check not recirculating in boxing. What sort of capacity is the system running at? What air on and off temps are you actually getting? Room temp?

31-10-2013, 08:33 AM
Did you followed start up procedure as it is written in installation manual? Adressing is OK?
What is outdoor unit model No?

31-10-2013, 03:56 PM
1. What mitsubishi? MHI or ME
2. Indoor and outdoor units names.
3. Outdoor and indoor temperature.
4. Equivalent length from OU to farthest IU (42 kg its a ****en lot)

p.s. somebody in UK help him with M-net or Menta for money.