Not to be funny, but anyone who doesn't know what the thingy is called, is best advised to get a licensed contractor to assess the problem. Every winter season has reports of houses blowing up from leaking or faulty gas furnaces, so why risk it to save the expense of a service call? Also, a new high efficiency unit with electronic ignition will probably save you a bundle in gas bills if your current system is more than 10-15 years old.

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1985 380SE Blue/Blue - 230,000 miles
2012 Subaru Forester 5-speed
2005 Toyota Sienna
2004 Chrysler Sebring convertible
1999 Toyota Tacoma