Me msh-18nv

[rude]

Went to a Mitsubishi Electric Hight wall split today Model - MSH-18NV. Now i couldnt gain access to the condensing unit but i suspect the unit short on refrigerant.

What was happening i would run the unit on cooling setpoint 16 room temp 25 and the unit would start cooling albeit not well. Then after 10secs the Reversing valve would click and unit would run heating for about 10secs then compressor would shut off.

Now my question is, is this normal? Is the unit defrosting the indoor coil due to below specfied coil temp?

Im not to familar with these units and id like a bit of a heads up before i go back. I think its a gas issue but just making sure. Also if anyone has a service manual that would be great as well.

Thanx

[coolhandlew]

Hi,
How can you tell that the reversing valve has energised? Sounds to me like it's got virtually no gas in it, it's just circulating ambient air (25 degrees) until it trips on LP.

[rude]

i can feel the evap pipes get warm.

[Brian_UK]

There could be a problem with the de-icer board but sounds odd.

Service Manual here if wanted, 3.18MB

http://es.mehvac.com/UploadedFiles/R...0059123856.PDF

[rude]

Thank you very much! I suppose when i gain access to condensing unit i can check the gas/boards etc

[Brian_UK]

Also, it depends on the type of 4-port valve, but low gas pressures can give those valves funny actions.