Jetjoc

I'm New Here
All of a sudden my altimeter is reading 4100 feet at a sea level airport about standard pressure. I have a vacume system anybody have any ideas on what happened?
 
Well, I hope you...

didn't hook your altimeter to your vacuum system;).

How long has it been in service? Any thing happen that might have affected it? Like someone blowing in it or anything weird?

Roger
-9A slow QB
 
Altimeters occasionally stick and have to be sent to a repair shop. Mine suffered that fate a couple of years ago. A shop in San Antonio repaired the altimeter and recalibrated it for ~$100 or so. You could probably find something on it in the RV-list archives.
 
Mine Too

Left the plane one weekend with the Alt. good and came back the next week and it was reading 3200 ft. high. Re-calibrated and everything is now fine.

Go figure.