How to check a position and modulation of a 4-Way Valve on VRV/F equipment in a few seconds! Place a magnet at the base of the valve moving it left to right until it grabs and sticks. Change the mode or demand of the unit to use all heat exchangers or by switching the system into 100% heat mode. Sit back and watch the magent move following the shift of the internal end of the 4-way valve! Easy! Check out the video discussing exactly this here: Mitsubishi Heat Recovery - K Gen - NO HEAT https://y