Heat Problem

[Wingman]

Hello guys need some help again. 2nd problem with smoker. Had the door replaced in the summer because bottom moulding cracked. Turned on smoker today to do bacon and  could not get box temperature passed 168 degrees. Thought something was wrong with my maverick probe but door gauge is reading 160 degrees also. Took a peekinside  and could see heat bulb is slightly red. Any ideas what to check? Thanks

[Tiny Tim]

Louvres on V-pan (make sure they're open), top vent (can't be full closed), slide switch (if full right, back it off slightly).  Make sure plugs are fully seated.  If none of these, it's over my head. lol

[Wingman]

 Vent never closed plugs were all in will check around heating element later.Why back off on the slider button? Thanks

[Tiny Tim]

On some units, there is a "Dead spot" at the far right of the slider...just something that happens with switches.