- Welcome to the forums! Glad you found us, lots of good folks here that are glad to help!
What make/model/year do you have? I assume you are not under warranty?
When you say it will not come on - does the blower come on or does it do nothing? If nothing, then not sure it is the sail or limit switch. How about the thermostat? Have you tested it?
At least on mine, if I fold down the sofa part way, I can then pull up the front panel and have a lot more room to get to the furnace.