I am replacing Direct Spark Controls on Radiant Heaters at the Shop. Some controls are 24V as the gas valve is 24V. Some of the older one's are 120V as the gas valve are 120V. The 120V units get 24V from Thermostat that runs through a step up transformer to 120V and then into the control. In an effort to make all of the controls the same. Could I wire it from the Thermostat 24V to a 24V control and take the gas valve leads from the control and run them through the transformer and then to the gas valve? (To test I wired the gas valve directly to the transformer and lite the unit manually and it seemed to be OK) The spark control is 15 seconds on 15 seconds off for three trials before cut-out so it seems like it would work fine. Does anyone see any issues with that method? Also I noticed that the electrode and sensor are so close to the flame that they glow red hot. Is that to close or are they designed to withstand that much heat?. I also have read that a ground should be run from the mounting screw of the electrode assembly back to the unit. I noticed that whoever converted them to direct spark did not do that. Would that lack of ground cause harm to the control?
I am thankful for any assistance that someone might give to one or all of my concerns. Thank You, Dwayne