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bryan mcmahon
15-10-2012, 08:47 AM
Hi all new to do a lot of air con working (mainly done fridge) but was looking for some help I fitted a new lev to a mitisbushi indoor unit vacced and recharged system and tested on cooling worked fine tested on heating and nothing happened it is a cityt multi r407c with bc box and 7 ducted indoor units and all indoors units not heating

AbsoluteWDJ
15-10-2012, 01:14 PM
Do you have local controls for each fan coil? If so, on test run (cooling or heating)the temperature displayed on local control would be the liquid pipe temperature. This gives you a good indication to see if each coil is doing what it's supposed to.

Cooling around 3c-9c
Heating around 33c-45c

What temperatures do you see?

Regards

bryan mcmahon
15-10-2012, 06:28 PM
On the local controls for cooling between 4-8 then on heating it was 18-22

install monkey
15-10-2012, 07:12 PM
reboot the system to reset the lev's as they go out of sync with time
press check button twice quickly to see if theres any fault codes.
if so press clock on/off twice quickly to clear the fault.
u can check fault codes on 1 indoor controller, no need to check each controller. press temp up to scroll through indoor addresses

stufus
15-10-2012, 10:41 PM
Rebooting the system wont sync up the LEV'S.
Each LEV will have to be manually reset.
Drop the power to the indoor and disconnect the M-NET transmission line and power back up wait 3 mins and drop the power again,reconnect the M-NET then power back up and on to the next indoor and repeat with all indoors and the BC.

What's the outdoor ambient??
And indoor ambient??
Run the indoor unit's alternately in heating and cooling(every second unit on the opposing setting)and check coil temps again
Cheers
Stu

jiminajam
16-10-2012, 07:05 AM
Are you getting hot gas to BC box? if so check LEV 3, If not check 4 way valve in condensing unit.

bryan mcmahon
16-10-2012, 08:49 PM
Called mitsubishi tech turn out its the four way valve thanks for the help guys :)

AbsoluteWDJ
03-11-2012, 12:59 PM
Called mitsubishi tech turn out its the four way valve thanks for the help guys :)


Good luck with this! They aren't the easiet valve to change. Also, I had the same problem once and thought the 4 way valve was faulty. Replaced the valve and discovered the exact same outcome no heating. It turn out to be the gause within the strainer had freed itself and stuck a check valve internally (CV2 I think). It'd work fine in cooling but bypassed hot gas down the suction in heating. Just a thought if the valve doesn't solve the problem.

paulr
30-11-2012, 01:10 PM
Rebooting the system wont sync up the LEV'S.
Each LEV will have to be manually reset.
Drop the power to the indoor and disconnect the M-NET transmission line and power back up wait 3 mins and drop the power again,reconnect the M-NET then power back up and on to the next indoor and repeat with all indoors and the BC.

What's the outdoor ambient??
And indoor ambient??
Run the indoor unit's alternately in heating and cooling(every second unit on the opposing setting)and check coil temps again
Cheers
Stu

Hi Stufus,

An engineer who visited my site did the sync by powering everything down, Outdoor, Indoors & BC. then he unplugged the MNET on the outdoor, powered everything back up for 3 mins then powered everything down, plugged MNET back into the outdoor and powered everything back up. not as thorough as doing each unit individually and with me not being an engineer wasn't sure if it would work that way but he was sure it would do all the units?

AbsoluteWDJ
30-11-2012, 03:41 PM
Hi Stufus,

An engineer who visited my site did the sync by powering everything down, Outdoor, Indoors & BC. then he unplugged the MNET on the outdoor, powered everything back up for 3 mins then powered everything down, plugged MNET back into the outdoor and powered everything back up. not as thorough as doing each unit individually and with me not being an engineer wasn't sure if it would work that way but he was sure it would do all the units?


Yeap, that would reset the LEV's as well.

stufus
30-11-2012, 10:06 PM
That'll work , I only do them individually so i can listen to each valve stepping.
cheers
Stu