I had that problem last winter with my 2012 Vista. The low voltage indicator after I had driven for 10 hrs so everything was charged. I found the control box and wiggled the connections and they worked for awhile and then it reoccured so I wiggled them again. After doing this dance all winter I took it for service and we replaced the solenoid and all has been well since. I think it was failing and the wiggling helped it to connect. Has been fine since replacing the solenoid. After three months sitting it is possible you do have low voltage but if you were plugged in and charging check the solenoid.
What solenoid did you replace? And where is it located?