Unit stops with E13; often occurs in heating mode on multi-split Toshiba systems.

Safety first: Disconnect power and do not attempt to heat the valve with open flame. Refrigerant circuit must only be opened by licensed technicians.

• Step 1 – Listen for valve shift: Command the unit from cooling to heating and listen at the outdoor unit for a distinct click of the four-way valve coil energizing.
• Step 2 – Check coil wiring: With power off, inspect the two wires going to the four-way valve coil. Ensure they are firmly connected and not damaged.
• Step 3 – Coil resistance: Disconnect the coil and measure resistance. Compare to Toshiba specifications (typically tens of ohms). Replace if open or shorted.
• Step 4 – PCB output check: If the coil is good, a technician should verify the outdoor PCB is supplying the correct voltage to the coil in heating mode.
• Step 5 – Mechanical valve issue: If the coil energizes but the valve does not shift (no change in pipe temperatures), the valve may be stuck and require replacement by a professional.