Mitsubishi electric PUH-P100

[eurocooling]

Hi I have a outdoor unit I put on test then the outdoor unit comes on the pipes starts freezing up and the receiver as well the outdoor fan just goes really slow for a min then it cuts out, put the gauges on when running on cooling gas pressure and power is fine on the indoor ducted unit theres no air pressure coming out of vents which it did work fine the code comes up on test run high abnormal temperature can any one help.
This unit is only 3 month old

[Thermatech]

If you can provide exact model of the outdoor & indoor units together with the exact fault code that would be helpfull.

If the indoor unit does not run the fan or there is some reason why there is no air flow through the indoor coil then in cooling mode the suction will frost & the system will stop on a fault.
Perhaps something simple like closed fire damper in the ductwork ?

[paul_h]

Sorry mate, we all have to get dirty sometimes.
Get in the ceiling.
Is the fan running?
If not - is there power to it, or a cap OK, or the windings normal resistance
If the fan is running - is the return duct clear, is the outlet ducting good.

With ducted a/c, you have to go into the ceiling, not troubleshoot from the outdoor unit, or the indoor outlets only.

[eurocooling]

Hi indoor unit fan works fine the duct system all clean inside blows fine on fan only

[eurocooling]

Hi the code coming up on the remote after test run is U1 this says abnormal high pressure overheating safeguard operation the model is Mr slim Pead-100 hope you can help as I live in Portugal and mitsubishi are not the best help here

Regards

Jason

[Thermatech]

U1 is high pressure safety switch activation

On R410a thats 4.15 MPa or aprox 41 bar

Suggest look at the following items

1/ Indoor air flow in heating mode
2/ Outdoor fan in cooling mode
3/ Refrigerant flow blockage ( outdoor LEV locked shut )
4/ 4WRV not operating

[install monkey]

service valves on the condenser closed,short of gas!

[marc5180]

Or non-condensables.

[eurocooling]

Hi again check everything on indoor unit blowing out hot air and cooling ok,when it gets to the vents nothing coming out this was perfect 3 months ago the outdoor unit comes on but the outdoor unit fan is very slow then compressor just switches of after 5 mins

[paul_h]

Look for dampers in the ductwork, eg manual dampers used for balancing, electric dampers used for zoning or fire dampers designed to close with fusible links if commercial property.
Also butterfly dampers may be fitted in the outlets may have closed themselves.