Criterion furnace won't ignite. Ten years old model rgpj-07namgr. Small motor on right kicks in. after 30 seconds, a clicking, the smell and hiss of gas for 5-8 seconds, another clicking and the gas shuts off. Small motor continues, after 1 minute the process repeats, and after the gas shuts off a second time the main blower motor kicks in and blows unheated air through the vents. Green LED remains lit, amber never lights up... hoping its just a bad thermocoupler...