I’m replacing a Williams gas valve with a new Robertshaw. The Williams has a commection for a limit switch and the Robertshaw does not. Where do I connect the limit switch? Williams model P172100A Robertshaw model 710 millivolt series.
There are 4 screw connections–
T-stat 1 and 3
Generator 2 and 4
Limit switch 2 and 3
Does that that sound right? These notes taken from a Williams installation
instruction.
Millivolt valve/ pilot generator/thermopile operation ‎(SublimeMasterJW’s Appliance Advice‎)thisvalve can have a limit device mounted in the wire coming out of the magnet in the picture here. You can cut the wire to magnet and install your fuse there with some butt connection and spade clips. By placing the fuse there you effectively kill the gas to the furnace when the fuse melts.
That magnet is needed in order to keep the gas flowing. But for safety reasons you need to shut it down if a fire occurs so what you do is place a fuse inline with that wire to the magnet. The valve will work great unless there is a fire in which the fuse melts, kills the magnet and thus the gas is shut down.:DClever ain’t it?