IMI Air con units

[Stuart]

OK any of you guys worked with IMI units

Have one that indoor unit runs not showing any faults, but outdoor doesn't kick in.

Close the contactor for the compressor & it runs.

Thermostat on indoor??

Capacitors on outdoor??

Board Knackerd??

Thoughts anyone.......

[Mark]

do you have a model no.it would help with fault finding .ie heatpump,impact,image e,mechanical,electronic,electromechanical
mark

[Andy]

Hi Stuart,
internal Klixon out on the compressor
Regards. Andy

[Brian_UK]

Stuart, without knowing the model number we are all guessing, but....
sometimes the head pressure control pipe sensor can go down which throws up a failure.

If you have another unit nearby, try a swap.

But yes, it could well be a board down, not unknown with IMI.

[Karl Hofmann]

Hofmanns rule of thumb:- Always start by checking for the simple faults first and work your way up to the expensive stuff but always explain to the customer that it COULD be something major and expensive, this way if it is expensive they're already primed for the bad news, if it is a simple and cheap repair then you become a hero and your name is passed on.

[FreezerGeezer]

Our splits were very simple, so I don't know if this will help, but:

Check that you have a cooling signal from your thermostat to your control board (I'm assuming the main control board is on the indoor unit).
If that is okay, and you're getting a signal for cooling back to the main board, then check that there is a signal out from the control board to the condenser. Ours send a 24V feed to the condenser, to activate the compressor contactor, and the condenser fan.
If there is no signal, then either:
The relay is knackered - replace the board.
There is a condensate overflow safety, or the condensate pump is wired in series with the compressor feed, and has failed. Either of which will stop a signal reaching the condenser.
If there is a signal out, then (on our units) it would have to be the H.P. or L.P. switch holding it off, since you say that the compressor will run if you hold in the contactor.

No doubt you've already done all this, and it's something more complicated. Sorry if I'm teaching anyone to suck eggs.

Karl, I like that philosophy!

[FreezerGeezer]

Our splits were very simple, so I don't know if this will help, but:

Check that you have a cooling signal from your thermostat to your control board (I'm assuming the main control board is on the indoor unit).
If that is okay, and you're getting a signal for cooling back to the main board, then check that there is a signal out from the control board to the condenser. Ours send a 24V feed to the condenser, to activate the compressor contactor, and the condenser fan.
If there is no signal, then either:
The relay is knackered - replace the board.
There is a condensate overflow safety, or the condensate pump is wired in series with the compressor feed, and has failed. Either of which will stop a signal reaching the condenser.
If there is a signal out, then (on our units) it would have to be the H.P. or L.P. switch holding it off, since you say that the compressor will run if you hold in the contactor.

No doubt you've already done all this, and it's something more complicated. Sorry if I'm teaching anyone to suck eggs.

Karl, I like that philosophy!

[Stuart]

All comments gratefully received

Freezer yes have tried your suggestions & I too think its a relay or thermostat prob.

For all you Techies out there.

Outdoor unit: HPUE100 3ph
Indoor unit: Image 120E (Twin Fan)

Brian- yes board change needed on outdoor I feel.

[BritCit_Juve]

If the unit is an Image E model then the indicator lams woul usually indicate the fault and the sounder would go.

first off though check termina 5 in the HPUE. if you have 240V there is a fault on the outdoor unit.
If you dont have any voltage then check the unit fuse. You should see around 70V normally.

On the indoor unit is the green led on? if not the unit doesn't want cooling so try resending the Cooling only signal or raise the temperature one degree. In both cases you should get a single bleep. If you get a double bleep then it doesnt like the command.

If you send a signal and get the sounder going around 16 times then you have an alarm such as
green led flash high condensate or pump fuse blown
Amber LED network fault
All three LEDs on Sensor fault indoor or outdoor
if outdoor terminal 5 would also be 240V

The E models work on a 2 wire data cable and if the outdoor unit is a heat pump both legs need to be good. If you have a green and red LED showing and 240 on terminal unit then the fault may be on the data cables. There are two ways to check em.
1 Force a fault. Remove one of the sensors off the liquid line sensor or
2 use an LED across the two data wires they should flash once every 3 seconds out and the return flash is a second later.

Note that if a unit attached to a heatpump HPUE/DHPUE/MHPUE unit will work in cooling but wont accept the heating command then the data cable is not connected correctly.
On the handset the transmission takes a finite time and it is possible for the display to over run ie display showes 16C but transmission still at 24C. just try raising the temperature to retansmit the present setting.


Lots of ramble but might help. let us know.

Never change an IMI PCB if you dont have to, unless your names Rockafella or beckham

Brit

[Stuart]

Thanks Britcit did most of what you said already.

Just so you all know pcb was blown...Hot & discoloured in one or two areas.

No faults shown on the indoor Brit it just ran but showed no faults. But yes it was an Image E

[Brian_UK]

Glad that you have sorted it Stuart, it all sounds like pretty standard IMI stuff.

I used to get wiring faults on the contactors which I put down to that *Friday manufacture* syndrome, they just didn't crimp the terminals properly and then they would overheat and burn-out.