[url]http://www.doityourself.com/forum/gas-oil-home-heating-furnaces/405179-all-burners-not-lighting.html[/url] I have a Payne Model PY1P - PY2P Packaged Gas Heating, Electric Cooling Unit. When it lights it lights all 3 burners but after a few seconds it will sound as if it is shutting off and relighting, it continues to do this, sometimes worse than others, makes puffing sound. Anyone have any thoughts on what the problem is? Thank You Woodgc

Although its a common topic in general I believe I have an interesting question. The background story to follow, here is the question: Why does simply blowing/sucking into my pressure switch until I hear it close seem to fix my furnaces... for a while, then I blow into it again to fix again? Is this ruining my pressure switch? I'm thinking not - I don't see how I can damage the diaphragm with my lungs. This has happened on 2 furnaces now both high efficiency gas furnaces. The first one I ran on Natural Gas, and my latest is Propane. At my old house (a 85% goodman of some sort, natural gas) the manometer showed about .60 WC (pressure switch said .75). I checked all the usually stuff, air flow was fine (disconnected both intake and exhaust), cleaned condensate trap, motor sounded fine. Simply blowing on the pressure switch, hearing it click, and re-attaching would fix it for a month or 2. This morning my frazer-johnson (G9t10014upc13c) - on LP - had the same 3 blink LED error (its been below 0°F here in MN -even during the day - for about 3 weeks straight now). Manometer reads 1.0 WC (although its homemade and not super accurate), pressure switch says .65. Blew on the lines to the inducer and chamber, blew on the pressure switch (till hearing the click), now its running fine again. I'm thinking I actually do have a bad pressure switch. Edit: originally i listed that i had a reading of 0.5 inches water this morning, i was only reading one half of my manometer and forgot to multiply by 2.