Carrier A/C problem

[Royal241]

I encountered a Carrier split system 40BNB018-036 that turns out to be a head scratcher. When first turned on in runs at low speed and blows cold air. 20 minutes later is blows hot air (80 F). 20 minutes later runs at high speed and blows cold air. The funny thing is that I never caught it acting up, but the guy keeps a temperature log and I believe him. This unit is one of those with a remote; somewhere in here I saw something about energy savers that interfere with the remote...?:rolleyes:

[amitsaxena]

There is a problem with the controller hence get it checked with authorised service person.