Most likely:

1. Low coolant: Since you had neither heat in the heater (which is
independent of the thermostat -- hence not thermostat problesm) or
radiator.

2. Slipping/broken pump belt. Check belt tension. Also check that
belt routing is per bentley (sloppy mechanics sometimes get creative,
and I've seen several cases where a 1-belt substitute for the
factory 2 belt setup has started slipping)

Good luck. Getting the temp needle a bit beyond centre is unlikely to
have damaged anything.

/Martin
(82 and 94 Westies)

 I just got my '82 diesel westy going after sitting all Winter, was
 going to leave today for a camping trip, but the battery had died (it
 was marginal anyway, and overdue for replacing) so after charging it
 overnight I went and bought a new one. Also got a new valvecover
 gasket and put that in to stop a leak there. So I had it sitting in
 the driveway idling for awhile, just to check whether the VC gasket
 leak was really fixed, and was puttering around getting the camping
 stuff ready, when I noticed the temp gauge way over the center
 mark. Never saw it there before. I had driven it around a bit
 yesterday and it never got up to full center, but then it never
 does. I shut it off and heard boiling noises in the rear, so started
 it up again and turned on the heat, but no heat came out of the
 heater, so I shut the engine down. It boiled out a bit from the
 resevoir tank, probaly a quart or two. I felt the radiator as best I
 could sticking my hand in thru the grill -- didn't feel warm. What
 gives? Once thing I noticed that was odd a couple of months ago --
 there was some coolant leaking out the rear by the tank, couldn't
 really tell where from, and then it stopped just as mysteriously as
 it started. The camper was parked at a fairly good slant with the
 nose up all Winter. When I checked coolant level the other day before
 starting it, it seemed fine. Could the slanted parking have done
 something weird? It was parked in the same place the Winter before
 too, but at least some of the time it was nose down.

-- Harmon Seaver CyberShamanix http://www.cybershamanix.com Hoka hey!