In heating operation, when each standard speed outdoor unit does not operate, the two-way solenoid valve stops each gas pipe.
This valve is external equalizing type, i.e. pressure difference to move the spool can be made outside of valve.
The valve “closes” when coil is energized, “opens” when not be energized.
The shape of the valve is similar to four-way valve and approx. 0.35MPa is required for operation.
Principal of Valve Operation
Basically, the principal of valve operation is the same as four-way valve. Below figure shows the operation of valve.