I have a Tempstar heating/AC unit in my home ... (with Honeywell valve model SV9500m-2682). When I turn on the heat, the only thing that runs is the induction fan(or whatever it is called), it just stays running all the time, nothing else ever happens. BUT, the unit for no apparent reason WILL run properly every once in a while. I checked the induction fan vaccuum diaphram and switch and determined both items are working. When the fan comes on, the switch closes. Do I have a bad honeywell valve or is a bad igniter a more likely culprit? What is the procedure to troubleshoot? is there a way to manually check the igniter? opinions?