carrier supra 950

[frigopat]

Lads I have a 950 which is not going on heat or cutting out at set point
I have checked the the valve when you power it up it works fine
How does the micro control this valve is the earth or the live from the micro that does it
Thanks Pat.

[cadwaladr]

is it charging correctly,water temp sensor can cause issues

[sonkax]

Micro controls with earth to the relay board.

[IRMechanik]

below 10F setpoint the unit will not go into heat (heat lockout)
battery voltage, water temp and minimum run time will keep the unit running.
Battery voltage should be about 13.6V give or take (varies on ambient) It will show a + sign before the voltage on the display if this is satisfied. and water temp should be at least 122F
Does it go into heat on initial startup? If it does, it proves the wiring and relay are all working.

[frigopat]

Yes I have seen water temp sensor on the screen only for a few second but no alarm
I will check this out and get back to you
Thanks

[frigopat]

Replacd water temp sensor but no good still having same trouble
Checked out mp 55 cable which supplys hot gas valve which as no out put if you set cab control to heat
The cab control will show the unit is heating but the relay is not pulled in
Replaced micro board unit will only cool and will not heat if set to heat on control
The only other thing is the vap fans wil come on when you switch the unit on and go off when it goes to start which i think there was a time delay on this
Can any one help??????

[cadwaladr]

Does it defrost? And are you sure it's configured to heat sometimes people reconfigure them to stop the driver messing with settings,do you know the history of the unit.

[frigopat]

Yes it will defrost if you manual hit the defrost button and the unit has with us a good few times
They run the unit at 0 most of the time and now and then at -20
It only started to go down past set point this week and will not control at set point

[IRMechanik]

Replacd water temp sensor but no good still having same trouble
Checked out mp 55 cable which supplys hot gas valve which as no out put if you set cab control to heat
The cab control will show the unit is heating but the relay is not pulled in
Replaced micro board unit will only cool and will not heat if set to heat on control
The only other thing is the vap fans wil come on when you switch the unit on and go off when it goes to start which i think there was a time delay on this
Can any one help??????

when you replaced the micro board did you mean the relay board or the controller?
If you replaced the controller, did you set all the configurations the same as the old one?
The fans cycling on and off sounds like it's not configured properly.

[frigopat]

The micro board on the door not the relay board in side the box
Yes they both were set up the same and the fans are doing the same thing with both micros

[sonkax]

Will display show heat mode? Will manual defrost, activate heat valve?

[frigopat]

It will show defrost mode on. But will not power relay for heat