When my York heat pump system made under the name (Central Enviromental Systems) was changed to heat mode this last fall the compressor cycled on for about 10 to 20 seconds then shut down. The compressor would then restart and repeat the short run time. This eventually burned up the compessor. I believe the compessor was dead headed as it was very loud. My first thought was the reversing valve is this the most likely cause? The system was fully charged and operting great in the cooling mode.