"lp13-30" wrote in message
...
Hi CB. A few years back I ran into something wierd on three T87's.
Somethng happened to the mercury in the bulb-- instead of being a shiny
silver, it was a grey that looked more llike molten lead, and flowed
like lead. Normally, as soon as the bulb moves just past level the
mercury rolls freely to the lower side. In these cases, the mercury
wouldn't move either way until the bulb was at damn near a 45 deg angle.
For the amount of temperature control that gave, they were more of a
toggle switch than a thermostat. The first one I saw was on a wall
heater. I had installed the stat the fall before, so it was replaced
under warranty. The other 2 were on central a/c-- age unknown, probably
5- 10 y/o. Both of those calls were in a/c season as I recall. Funny,
never seen anything like that on any other mercury bulb stat, and never
seen another one since the last of those three, about 7 years ago more
or less. Larry


Ran into maybe three total like that...one wasnt in a Honeywell..it was some
cheapy china thing that looked like a Robertshaw, but was WAAAAY cheaper.
I like the T87s, but at least with a digital higher quality stat, you can
eliminate alot of issues down the road.

On another odd note, had a good customer of mine call this morning..has a
Payne unit that so far has about been rebuilt, but he wont replace it..yet..
Said what was going on, was his nice "high quality" Totaline stat was
reading AUX no matter how he turned the heat on..
SWORE the outside unit was running.
Long story short, outside wasnt running. Compressor lead had broken loose
and was rubbing on the suction line on the heat pump..insulation wore off,
tripped the breaker, and the resulting hole, of course, tripped the LP
switch.....damndest thing I had seen so far this year. Once it was repaired,
vac;d, charged, and running, no more AUX...Im still trying to figure out how
it was knowing the comp was out, yet, no L wire, and thus, no feedback to
the stat.