I have a propane furnace that will not ignite. The blower runs constintly unless you phyically shut it off. What could be wrong? Thanks, Tim

Brand and Exact model?

brand and exact model?

Nordyne model m3rl08oa bw

nordyne model m3rl08oa bw

Nordyne model m3rl080a bw

Most modern furnace control systems will default to a continuous fan and defeat all other functions (i.e. no heat) if a limit circuit is open, and in most cases the limit circuit is identifiable by red low voltage wires. Check the limit control device(s) for a broken circuit.

It may be the igniter or the gas valve. If your furnace has a carbon type "hot surface" igniter, you may want to check it for cracks. You also may want to check the LP tank and it is possible for your pressure regulator to have gone bad.