Help,I have two problems.. My upstairs furnace pilot light will light,and after holding down the pilot button for about 3-4 minutes(it says one minute,but it won't stay lit after only one)it stays,but will go out again in a day or two... The furnace for the downstairs won't light at all.. I can't afford a hvac service call,and I'm an electrican so I do have mechanical ability to fix the problem myself, I just don't know what to fix.. What are some things I should check or replace?