A little help would be appreciated. My old gas wall heater has the pilot on no problem and when I turn the dial to heat as usual i hear a "click" and then usually hear the gas ignite and light up. For some reason there is no "hiss" of the gas coming out and and nothing is lighting. I dont smell gas and am not sure why nothing is coming out. Any tips would save me a bit of money calling the repair guy. besides its fun to fix stuff!