My electric intertherm heater will not trigger a light to start the heater on the furnace. It just makes the sound of running, but does not heat. Prior to this, my heater would turn on and off frequently? I had not used it in the last 6 months or so. I tried to turn it on, just won’t work properly now. No heat on any turnover of trigger of ignite

Lets start with a model number since there are several.