Yes it is a Reliatel and yes we do have 24 volt to solenoid - heating mode is still running even in cooling mode -- pulled leads of of reversing valve usually that will slide it over but it is still in heating
Please try to measure your 24 volts at the reversing valve with an analog voltmeter;not a digital meter. Before this beats you up, try an external 24 volt supply to the valve. @4 volts should give you cool no 24 volts gives heat.
-rv engergized in cooling , you have 24v at rv coil , unwire coil and do a continuity check.
-lightly tap on ends and side of rv with 24v present.
-new rv's are china and junky. Ranco seems to be long gone. They have a poor material for the piston and can be easily frozen during the brazing process. The capillary lines are also problematic.
-if the coil checks good and you have voltage , but its still in heat , then bad valve.
-if it changes over while tapping on it , then you still have a bad valve , but it is now cooling.
-this is a new unit warranty situation , if it were not then adding SUPCO oil and allowing to circulate through for a while , then tapping on the valve very patiently over and over will work about 60% of the time.
-also the china bodies are easily distorted during heavy handed installation and it takes very little runout to cause a piston to bind.
If you do have to replace the valve under warranty you can :
-pump out the unit by closing the liquid line valve and watching your suction pressure by connecting to a true suction port inside the unit. (since it is stuck in heat)
-when installing the new valve what works well is to carefully coat the entire valve in heat paste , then wrap in wet rags and have a helper add droplets of water to the wet rags during brazing.
-use a relatively high heat to braze as quickly as possible.
-you can cut the old valve out with long stubs and bench braze the stubs using the method on a work surface , then use couplings to install the new valve in unit.