How does the CK-20F/HWK work with a residential gas water heater?
The kit includes a gas pressure switch with a set of normally open contacts to switch 120 vac to the power venter motor. The switch senses an increase in gas pressure in the manifold side of the gas valve. The power venter and burner start at about the same time. Two normally closed spillage switches are also included and mount on the draft hood. These spill switches trip if the temperature reaches 180F. They are wired in series with the 30-millivolt circuit using a thermocouple adapter.
