We're having issues with our forced draft gas fired furnace... Which was installed in 1990...

Whats happening is that occasionally when the thermostat calls for heat, is you can hear the furnace try to start up, but it wont start up even after 5-15 mins. The problem is solved when the thermostat is turned down a few degrees, then turned back up.

Any help? And if it needs to be replaced, whats a good one? Looking for a good price, and efficiency. Dont know what else to look for either.
TKs
~Nate

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95 Honda Shadow ACE 1100.
1999 Plymouth Neon Expresso. 2.4 swap, 10.5 to 1 comp, big cams. Autocross time attack vehicle!
2012 Escape, 'hunter" (5 sp 4cyl)