"Art Todesco" wrote in message
news:_Ypvb.267613$Fm2.280381@attbi_s04...
I hate to "reply" to my own post, but I just remembered some
additional info. I originally bought a 3200, which has an
electronic switch (triac) to turn on the gas valve. Well, on my
old furnace (1970 model) it would not let the gas valve close
completely due to some minute leakage of the switch device. On
warmer days, where little heat was required, I noticed a very
slight smell of gas right in front of the burners. Honeywell
tech people responded that this can sometimes happen and sent me
a new model that has a relay in it. It was a 3400 (I just
pulled off the front to check) which solved the problem and is
still working perfectly. BTW, the old 3200 is still being used
for AC as a 2nd thermostat for pseudo zone control.

And if you had talked to someone at Honeywell that knew what he was doing,
he could have sent you for free the resistor that should have been in the
box to start with...



Art Todesco wrote:

I too, have one of the Honeywells. I can't seem to find the model
number on the unit, but I remember that it was something like the
previous poster's 3500 or 3600. It has the "electronic anticipation"
and has worked extremely well with my gas furnace. I have also checked
it with both termocouples and traditional mercury thermometers and found
it to be right on. Occationally, and very occationally at that, I do
get an anticipator failure. By this I mean that the furnace fires up
and then, before the blower comes on, it shuts down. This seems to be
related to the temperature and temperature changes. As I said, it only
happens extremely rarely. BTW, one of those "smart" furnace guys came
into my house and said "the Honeywell is junk." He's junk. This is why
I do most of my own rebuilding/repair. BTW, I once bought a digital
thermostat that advertised a +/- 1/2 degree accuracy. It had no
anticipator. It, combined with the gas furnace, overshot by 6 or 8
degrees. I returned it right away. It had a bunch of big C batteries
in it. BTW, the Honeywell batteries (I think they're AAs) last for
years. I don't know when I last changed them and they are still going
strong. Great Product!

David Efflandt wrote:

On Thu, 20 Nov 2003, CBHvac wrote:

"Steve Stone" wrote in message
...

Don't most stats have a plus or minus 3 degrees or so in latitude in
when
they turn off or on ?


They do.
There is a reason for this, and a good Honeywell mercury switch stat,
can be
better than a Chronotherm model when it comes to comfort.
Its called a dead band, and since MOST people can not actually feel
the 3F
difference in temps, you never know.



The RobertShaw thermostat that came with my house was +-1 (2 degree F
spread) at best, and usually overshot 1-2. It had no anticipator
setting,
just gas/electric switch.

I changed to Honeywell CT3500 (should have gotten CT3600) with 1 degree
spread, and by comparing air and wall termperature learns to
electronically anticipate temperature rise to shut off before it
reaches
setting if necessary (since steam radiators retain heat), and ramps up
from setback instead of all at once. It only rarely overshoots
slightly
if the weather suddenly turns very mild. The only reason I would have
liked the CT3600 is because it logs total run time to tell most
effective
setback.

I don't know if the original poster gave a model number or whether it
was
wired or set properly for their hydronic system. But my Honeywell
electronic works great for single-pipe steam, although, I my old home h
as
plenty of thermal mass (drywall over plaster), so temperature changes
are never sudden.