A couple of years ago the furnace was replaced and a new thermostat
installed. The new thermostat is identical to the old one. The temperature
never reaches the setpoint. Currently the temperature reaches about 70
degrees with the setting at 73. Also the new furnace seems to cycle on and
off more frequently than the old one. The new one is a much higher
efficiency. Should I try a new thermostat or reinstall the old one? Or
just accept the bias? The old one had a wider "span" setting.

If you're getting the room temperature reading off of the thermostat, and
not a remote thermometer, I'd say you have a bad unit. I'd try the old one




"Ronald'" wrote in message
...
A couple of years ago the furnace was replaced and a new thermostat
installed. The new thermostat is identical to the old one. The
temperature never reaches the setpoint. Currently the temperature reaches
about 70 degrees with the setting at 73. Also the new furnace seems to
cycle on and off more frequently than the old one. The new one is a much
higher efficiency. Should I try a new thermostat or reinstall the old one?
Or just accept the bias? The old one had a wider "span" setting.

Ronald' wrote:
A couple of years ago the furnace was replaced and a new thermostat
installed. The new thermostat is identical to the old one. The
temperature never reaches the setpoint. Currently the temperature
reaches about 70 degrees with the setting at 73. Also the new
furnace seems to cycle on and off more frequently than the old one. The
new one is a much higher efficiency. Should I try a new
thermostat or reinstall the old one? Or just accept the bias? The
old one had a wider "span" setting.

Depending on the thermostat, you may be able to adjust those factors.
Do you have the manual that came with the thermostat? If not try the
manufacturer's web site and see if they have a downloadable manual.

--
Joseph Meehan

Dia 's Muire duit

If you have a Honeywell mercury thermostat, Make sure it is level. A
slight "tilt" will change the settings.


---MIKE---
In the White Mountains of New Hampshire
(44° 15' N - Elevation 1580')

Ronald,

You say that the temp never reaches the setpoint but you also say that
the furnace is "cycling". What is causing the furnace to shut off before it
reaches the setpoint? Remove the thermostat and jumper the heating wires.
Does the furnace cycle or does it keep running. If the furnace shuts off
call a furnace guy. If the furnace doesn't cycle then the problem is with
the thermostat.

Dave M.

On Feb 1, 8:36 am, (---MIKE---) wrote:
If you have a Honeywell mercury thermostat, Make sure it is level. A
slight "tilt" will change the settings.

---MIKE---In the White Mountains of New Hampshire

(44° 15' N - Elevation 1580')


Ever see a mercury thermostat with adaptive recovery?

On Feb 1, 8:54 am, wrote:
On Feb 1, 8:36 am, (---MIKE---) wrote:

If you have a Honeywell mercury thermostat, Make sure it is level. A
slight "tilt" will change the settings.

---MIKE---In the White Mountains of New Hampshire

(44° 15' N - Elevation 1580')

Ever see a mercury thermostat with adaptive recovery?

Ooops, wrong thread, my bad! But still, he said it was a new
thermostat. They stopped selling mercury thermostats a long time ago.

This is a mercury thermostat and was "new" with the installation of the
furnace 2 years ago.

On Thu, 1 Feb 2007 09:05:13 -0500, Ronald' wrote:


This is a mercury thermostat and was "new" with the installation of the
furnace 2 years ago.

I assume you spend more than fifty bucks for the new furnace? Why not spend
another thirty bucks and get a thermostat using technology from this
century? Why the eight dollar thermostat?

It's the basic Honeywell round thermostat.

Ronald' wrote:
This is a mercury thermostat and was "new" with the installation of
the furnace 2 years ago.

I think I would opt for a more modern thermostat. However it is still
possible to be a furnace problem. They will shut down if they sense an
overheat situation in the furnance.

--
Joseph Meehan

Dia 's Muire duit

On Feb 1, 9:05 am, "Ronald'" wrote:
This is a mercury thermostat and was "new" with the installation of the
furnace 2 years ago.



Well, you learn something new everyday. I thought mercury thermostats
had been totally phased out. But it looks like only some states have
passed laws banning them and they can still be sold in other states.
It amazes me that there isn't a FED ban on them by now, as mercury is
a hazardous waste and this is an application where it can easily be
replaced. Also kind of amazing that with a new furnace install, they
wouldn't give you at least a cheap programmable.

So, I agree with Mike and would check that it's level, because if it
is not, this is the problem that results.

"Ronald'" wrote in message
...
This is a mercury thermostat and was "new" with the installation of the
furnace 2 years ago.

It is also possible it is reaching the "set point" but not the indicated
point. Some cheap thermostats never read quite right. What is the actual
temperature from a real thermometer? Maybe it should be swapped out for a
good programmable model.

On Thu, 1 Feb 2007 09:15:49 -0500, Ronald' wrote:


It's the basic Honeywell round thermostat.

The height of seventeenth century technology.

http://www.tecsoc.org/pubs/history/2002/nov7.htm

The actual temperature is exactly the same as indicated on the thermostat -
measured with 2 different thermometers. The last I looked, this thermostat
was commonly sold in stores. I called the outfit that installed the
furnace. They now supply a different brand and type of thermostat. It
seems that I will be crawling out of the dark ages.

In article . com, wrote:
On Feb 1, 9:05 am, "Ronald'" wrote:
This is a mercury thermostat and was "new" with the installation of the
furnace 2 years ago.



Well, you learn something new everyday. I thought mercury thermostats
had been totally phased out. But it looks like only some states have
passed laws banning them and they can still be sold in other states.
It amazes me that there isn't a FED ban on them by now, as mercury is
a hazardous waste and this is an application where it can easily be
replaced. Also kind of amazing that with a new furnace install, they
wouldn't give you at least a cheap programmable.

So, I agree with Mike and would check that it's level, because if it
is not, this is the problem that results.

Yeah, but the OP might as well replace the existing thermostat
with a programmable electronic one. Sensibly programmed, it
will pay for itself in very short order. They're available at
very low cost at many outlets including Walmart and Target.
Just be sure to buy a unit suitable for your furnace/system.

This may solve all of his problems. If it doesn't, there may
be a seperate issue causing the furnace to cycle and that will
have to be investigated.

But there's a good chance a new thermostat will fix the
problem and save money.

--
|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~|
| Malcolm Hoar "The more I practice, the luckier I get". |
| Gary Player. |
| http://www.malch.com/ Shpx gur PQN. |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~

I bought a new one last year, Honeywell.
wrote in message
ups.com...
On Feb 1, 8:54 am, wrote:
On Feb 1, 8:36 am, (---MIKE---) wrote:

If you have a Honeywell mercury thermostat, Make sure it is level. A
slight "tilt" will change the settings.

---MIKE---In the White Mountains of New Hampshire

(44° 15' N - Elevation 1580')

Ever see a mercury thermostat with adaptive recovery?

Ooops, wrong thread, my bad! But still, he said it was a new
thermostat. They stopped selling mercury thermostats a long time ago.

"Ronald'" wrote in message
...
The actual temperature is exactly the same as indicated on the
thermostat - measured with 2 different thermometers. The last I looked,
this thermostat was commonly sold in stores. I called the outfit that
installed the furnace. They now supply a different brand and type of
thermostat. It seems that I will be crawling out of the dark ages.


In that case, the indicator dial is probably off. Set it to 76 to reach 73.
Problem solved.

Best bet is still a programmable if you want to save some heating money. In
my house, they go up to 70 degrees first thing in the morning, then drop
back to 68 for the rest of the day, then to 64 at night for comfortable
sleeping. The heat comes on 15 minutes before I get out of bed. Works
well.

On Feb 1, 1:00 pm, "Ronald'" wrote:
The actual temperature is exactly the same as indicated on the thermostat -
measured with 2 different thermometers. The last I looked, this thermostat
was commonly sold in stores. I called the outfit that installed the
furnace. They now supply a different brand and type of thermostat. It
seems that I will be crawling out of the dark ages.

Programmable is the way to go. We had an old mercury t-stat when we
bought our place and had problems getting the temperature set. It
would usually get hotter than the preset temperature. The programmable
we have now is dead nuts on. Very consistent. It's set for 68 when
we're home and that's the reading we get on the t-stat unit in the
hallway and on the thermometer in the living room. I love it. It
pretty much paid for itself last year when natural gas prices were so
high. Now we're looking at getting a new furnace this spring. Our
current one is old (at least 20yrs.), but is very reliable. It's just
not very efficient and I worry about the condition of the heat
exchanger.

-Felder