Got a newfangled high efficiency furnace, has 2 speeds. When on full,
no problem, pumps lots of hot air out the ducts at 118 to 127 degrees.
However on low speed, it just pushes air at ambient tempature through
the ducts. I put a thermometer in the duct, and the air moving is
usually about 2 degrees cooler than the room temperature. Clearly in
low speed the blower is running, but air is not being heated.
Am I wrong, I thought in low speed the air is still supposed to be
Yep the air is supposed to be heated, just doesnt blow as
Sounds like either the normal (lower) stage isnt working or the
guy who wired it up didnt do it right. (make sure the themostat isnt
on fan before anything else)
This is a guess... but - do you know, for certain, that you had a 2
stage thermostat installed? When they put my 2 stage system in, they
never bothered to change the thermostat, and simply set dip switches on
the board to have the furnace kick into high speed if the low speed had
been running for 5 minutes or so.
Reason I ask is - your furnace may be set up to only run at high speed,
and then it kicks into low when the burners shut off.
Good question... I don't know. I picked up an expensive one for about
60 bucks at Costco about 6 years ago when I wanted a timer one, and
installed it myself.
A furnace company put in the 2 stage Furnace a month or two ago.. .they
didn't change thermostats. Is there anything I should look for on the
Thermostat? I am pretty certain it is a Honeywell, don't know model
number. Just one of those that have the timer..with a lot of settings.
It's almost assured that you don't have a dual stage thermo. I'm not an
HVAC guy, not even close... but if your thermostat is 6 years old, and
they didn't replace it or rewire it - I'd bet your system was not
It seems ridicuosly common for new install of dual stage systems to not
be put in right. I've no idea why this is. But in order for you to
truly get what you paid for, and the benefits of dual stage heating -
you need a dual stage stat.
I'd call the company up, ask why they didn't install a 2 stage stat,
and get them back out to finish the job properly. I'm sure an HVAC tech
will jump in here soon with other advice. Bubba, you out here?
Yup. Same here. A two stage furnace gets a 2 stage stat, PERIOD!
You didnt tell the installers that you wanted to keep that $60
thermostat, did you?
Get it done right or dont spend the extra money on a 2 stage furnace.
My guess is that the guy quoted me a flat price.. 4k for furnace and
AC, and didn't want to eat the price of a new t-stat. It never came
up, I didn't know I would need a new one, or I certainly would have had
him put a new one in... even if I had to eat the cost.
Anyway I called them and they are coming out tormorrow to look at it...
seems like that follow up call will cost them a bit of money, and they
would have been wise to do it correctly the first time.
Just thought of a follow up Q--- should I just go out tonight and buy a
quality 2 stage T-stat (since i do want the timer functions, so it
auto-turns down at night, etc) and leave it for the guy to install, so
he doesn't put junk in without a timer... and I don't have to come back
later to put a nicer one in.. and possibly screw up the wiring in the
If I do pick one up at costco.. will it be clearly marked as a 2 stage?
Good luck finding a two stage stat! You may find one of the new Honeywell
8000 series, touch screen, stats that will control a two stage, but I think
a two stage stat at your local home center may be a bit of a rarity.
If you find one it will be indicated for two stage, or labeled for two heat,
Most two stage furnaces will run on a single stage stat, but they will run
better on a two stage stat.
I had a new furnace put in last year. Every proposal included a new
thermostat, even though the old one was fine. They just didn't want to foul
up the job with old stuff. They even replaced all the gas pipes and valves.
Most two stage furnaces can be setup to work on a single stage stat or two
In single stage mode the lower stage runs for a set time and if there is
still a call for heat, the high stage is energized until there is no call
I like the single stat mode better because, if the stat is turned up in mild
weather the second stage isn't energized.
and if you set it back on a cold night you can have up to 15 mins
before it ever starts to get warm. That can seem like an eternity on a
cold cold morning. Do it right the first time.
On Thu, 17 Feb 2005 03:13:21 GMT, "Terry"
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