Air Conditioning/Thermostat Selection
randallbrink
central fan does not come on, and so, while the air conditioner
outside runs, it quickly freezes, as there is no air movement. On the
other hand, if I select the heat-cool switch to "Off" and turn the fan
"On" the fan works fine. But if while the fan is running, I move the
Heat-Cool switch to "Cool" the fan shuts off. I have replace the
thermostat, and have the same problem.
Any help will be greatly appreciated, as the outdoor temperature is
now 90F.
Telstra
"randallbrink" <randal...@gmail.com> wrote in message
news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
Telstra
"randallbrink" <randal...@gmail.com> wrote in message
news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
Nate Nagel
Is your thermostat such that you can access the wires connected to it
while it is operational? you ought to slap a meter on there and figure
out if the issue is with the thermostat not commanding the fan to be on
or if it's in the furnace. If your furnace is like mine, the fan is
controlled at different speeds for each of heat, cool, and manual fan on
- so at least in my case, if I were having your problem I'd be digging
into the control board for the furnace not the thermostat. If however
you have a single speed fan, it would likely be the thermostat. Which
kind of setup do you have?
good luck
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
Tony Hwang
Model of outside unit, furnace inside and your thermostat?
Do you have a multimeter? How many wires are on the 'stat.
When you are calling for cooling, you should see 24V AC between
terminals on the 'stat R and G and again between R and Y(since outside
fan runs you must see 24V AC here) If you don't see 24V AC between R and
G 'stat is bad.
randallbrink
> POST the make and model # of thermostat
>
The first was an AprilAire 8363, the new one a Honeywell T87N
randallbrink
I'll do this test. However, the same problem has re-occured after
replacing the thermostat. I can, however, access the wiring with the
system in operation.
Mikepier
fan and compressor are working, which is good. You just need to
confirm if the wiring is correct. If it is, it could be a defective
circuit board on your A/C unit.
Roy Starrin
<randal...@gmail.com> wrote:
>I have a puzzling problem. When I select "Cool" on my thermostat, the
>central fan does not come on, and so, while the air conditioner
>outside runs, it quickly freezes, as there is no air movement. On the
>other hand, if I select the heat-cool switch to "Off" and turn the fan
>"On" the fan works fine. But if while the fan is running, I move the
>Heat-Cool switch to "Cool" the fan shuts off. I have replace the
>thermostat, and have the same problem.
Did this just suddenly happen to an existing installation, or was
anything changed in the installation before the problem began, e.g.
wiring, equipment, supporting electrical wiring, etc.
randallbrink
Furnace is Coleman 8.T and the AC unit is a Lennox HS18-411-5P.
Telstra
and ( G ) on the indoor unit is connected to ( R ) thermostat then
with the fan on it would connect G to R and with the cooling on R
to ( Y ) with ( G ) OFF
Check the wire colour on the indoor Unit R - Y - W - G and make
sure these are connected to the right thermostat terminals
"randallbrink" <randal...@gmail.com> wrote in message
news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
randallbrink
> If ( R ) on the indoor unit is connected to ( G ) on the thermostat
> and ( G ) on the indoor unit is connected to ( R ) thermostat then
> with the fan on it would connect G to R and with the cooling on R
> to ( Y ) with ( G ) OFF
>
> Check the wire colour on the indoor Unit R - Y - W - G and make
> sure these are connected to the right thermostat terminals
>
>
> news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
>
> >I have a puzzling problem. When I select "Cool" on my thermostat, the
> > central fan does not come on, and so, while the air conditioner
> > outside runs, it quickly freezes, as there is no air movement. On the
> > other hand, if I select the heat-cool switch to "Off" and turn the fan
> > "On" the fan works fine. But if while the fan is running, I move the
> > Heat-Cool switch to "Cool" the fan shuts off. I have replace the
> > thermostat, and have the same problem.
>
> > Any help will be greatly appreciated, as the outdoor temperature is
> > now 90F.
By "Indoor Unit" I assume you mean the furnace blower?
Nate Nagel
yes, that is correct (or air handler if you have a heat pump)
randallbrink
All of the wiring seems to be correct in accordance with the
installation instructions. And still, when I turn the "Heat-Cool"
switch "Off" and move the fan switch from "Auto" to "On" the fan comes
on. If I put the fan switch on "Auto" and turn the AC to "Cool" the
AC fan comes on and cold air enters the building, but wothout the fan,
it does not move and the AC unit soon freezes up.
Telstra
2- Check fan setting switch set to F
3-Put the wire going to G on the thermostat to the R
Terminal on the thermostat so the R terminal has
two wires R and G ( The fan should run without )
changing the thermostat switch )
"randallbrink" <randal...@gmail.com> wrote in message
news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
randallbrink
> 1- Check the Wire link R to Ro is inserted
>
> 2- Check fan setting switch set to F
>
> 3-Put the wire going to G on the thermostat to the R
> Terminal on the thermostat so the R terminal has
> two wires R and G ( The fan should run without )
>
> news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
>
> >I have a puzzling problem. When I select "Cool" on my thermostat, the
> > central fan does not come on, and so, while the air conditioner
> > outside runs, it quickly freezes, as there is no air movement. On the
> > other hand, if I select the heat-cool switch to "Off" and turn the fan
> > "On" the fan works fine. But if while the fan is running, I move the
> > Heat-Cool switch to "Cool" the fan shuts off. I have replace the
> > thermostat, and have the same problem.
>
> > Any help will be greatly appreciated, as the outdoor temperature is
> > now 90F.
Will do. Thanks!
randallbrink
>
> 2- Check fan setting switch set to F
>
> 3-Put the wire going to G on the thermostat to the R
> Terminal on the thermostat so the R terminal has
> two wires R and G ( The fan should run without )
>
> news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
>
> >I have a puzzling problem. When I select "Cool" on my thermostat, the
> > central fan does not come on, and so, while the air conditioner
> > outside runs, it quickly freezes, as there is no air movement. On the
> > other hand, if I select the heat-cool switch to "Off" and turn the fan
> > "On" the fan works fine. But if while the fan is running, I move the
> > Heat-Cool switch to "Cool" the fan shuts off. I have replace the
> > thermostat, and have the same problem.
>
> > Any help will be greatly appreciated, as the outdoor temperature is
> > now 90F.
Mystery continues. I put the "G" wire on the "R" terminal, yes, the
fan did operate without changing the switch position. However, as soon
as I selected "Cool" the A/C came on and the fan in the house stopped
again.
Telstra
Make up a jumper wire one foot long - bare a 1/4 inch at
each end.
1 Bridge R to G Fan should run
2 Bridge R to Y cooling should start after timer delay
3 Bridge R to W Heating
24 V is a low voltage however care should be taken
R is the 24V Active which is switched by the Stat to
Outputs G + Y ( Cooling ) G + W ( Heating ) G Fan
"randallbrink" <randal...@gmail.com> wrote in message
news:f8182a42-edf5-4ae3...@j33g2000pri.googlegroups.com...
randallbrink
> Cycling the system
>
> Make up a jumper wire one foot long - bare a 1/4 inch at
> each end.
> 1 Bridge R to G Fan should run
> 2 Bridge R to Y cooling should start after timer delay
> 3 Bridge R to W Heating
> 24 V is a low voltage however care should be taken
> R is the 24V Active which is switched by the Stat to
> Outputs G + Y ( Cooling ) G + W ( Heating ) G Fan
>
>
> news:f8182a42-edf5-4ae3...@j33g2000pri.googlegroups.com...
> On May 17, 6:26 pm, "Telstra" <tfwil...@clear.net.nz> wrote:
>
>
>
> > 1- Check the Wire link R to Ro is inserted
>
> > 2- Check fan setting switch set to F
>
> > 3-Put the wire going to G on the thermostat to the R
> > Terminal on the thermostat so the R terminal has
> > two wires R and G ( The fan should run without )
> > changing the thermostat switch )"randallbrink" <randallbr...@gmail.com>
> > wrote in message
>
> >news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
>
> > >I have a puzzling problem. When I select "Cool" on my thermostat, the
> > > central fan does not come on, and so, while the air conditioner
> > > outside runs, it quickly freezes, as there is no air movement. On the
> > > other hand, if I select the heat-cool switch to "Off" and turn the fan
> > > "On" the fan works fine. But if while the fan is running, I move the
> > > Heat-Cool switch to "Cool" the fan shuts off. I have replace the
> > > thermostat, and have the same problem.
>
> > > Any help will be greatly appreciated, as the outdoor temperature is
> > > now 90F.
>
> Will do. Thanks!
OK, will try it.
Tony Hwang
Sounds like you have bad 'stat/
randallbrink
Well, I've already installed a new thermostat, and still have the same
symptoms. Odds are not good that two new thermostats would be faulty.
randallbrink
>
> Make up a jumper wire one foot long - bare a 1/4 inch at
> each end.
> 1 Bridge R to G Fan should run
> 2 Bridge R to Y cooling should start after timer delay
> 3 Bridge R to W Heating
> 24 V is a low voltage however care should be taken
> R is the 24V Active which is switched by the Stat to
> Outputs G + Y ( Cooling ) G + W ( Heating ) G Fan
>
>
> news:f8182a42-edf5-4ae3...@j33g2000pri.googlegroups.com...
> On May 17, 6:26 pm, "Telstra" <tfwil...@clear.net.nz> wrote:
>
>
>
> > 1- Check the Wire link R to Ro is inserted
>
> > 2- Check fan setting switch set to F
>
> > 3-Put the wire going to G on the thermostat to the R
> > Terminal on the thermostat so the R terminal has
> > two wires R and G ( The fan should run without )
> > changing the thermostat switch )"randallbrink" <randallbr...@gmail.com>
> > wrote in message
>
> >news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
>
> > >I have a puzzling problem. When I select "Cool" on my thermostat, the
> > > central fan does not come on, and so, while the air conditioner
> > > outside runs, it quickly freezes, as there is no air movement. On the
> > > other hand, if I select the heat-cool switch to "Off" and turn the fan
> > > "On" the fan works fine. But if while the fan is running, I move the
> > > Heat-Cool switch to "Cool" the fan shuts off. I have replace the
> > > thermostat, and have the same problem.
>
> > > Any help will be greatly appreciated, as the outdoor temperature is
> > > now 90F.
>
> Will do. Thanks!
P.S. What should I expect to see happen with this procedure? And with
what T'stat switch positions?
Thanks again!
Telstra
Connecting R 24V Active from the transformer to the
G Fan relay Y Compressor relay or W Heating relay
will energise these relays regardless of the thermostat
setting. If this does not occur then R is really Gand G
R. That is the wire to G is really the 24V active and
the wire to R is from the fan relay.
However if it does work correctly then the thermostat
wiring is correct and the fault is in the Indoor Unit
either the transformer or the wiring. My guess is the
wiring, perhaps a loose or burnt wire.
The assumption of course is that the unit worked
correctly when it was installed.
However it appears that the fault is in the indoor unit
wiring
"randallbrink" <randal...@gmail.com> wrote in message
news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
randallbrink
> Cycling the system
>
> Connecting R 24V Active from the transformer to the
> G Fan relay Y Compressor relay or W Heating relay
> will energise these relays regardless of the thermostat
> setting. If this does not occur then R is really Gand G
> R. That is the wire to G is really the 24V active and
> the wire to R is from the fan relay.
> However if it does work correctly then the thermostat
> wiring is correct and the fault is in the Indoor Unit
> either the transformer or the wiring. My guess is the
> wiring, perhaps a loose or burnt wire.
> The assumption of course is that the unit worked
> correctly when it was installed.
>
> However it appears that the fault is in the indoor unit
> wiring
>
>
> news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
>
> >I have a puzzling problem. When I select "Cool" on my thermostat, the
> > central fan does not come on, and so, while the air conditioner
> > outside runs, it quickly freezes, as there is no air movement. On the
> > other hand, if I select the heat-cool switch to "Off" and turn the fan
> > "On" the fan works fine. But if while the fan is running, I move the
> > Heat-Cool switch to "Cool" the fan shuts off. I have replace the
> > thermostat, and have the same problem.
>
> > Any help will be greatly appreciated, as the outdoor temperature is
> > now 90F.
Thank you very much for this clarification. I will now carry out this
test and see what happens.
randallbrink
>
> Connecting R 24V Active from the transformer to the
> G Fan relay Y Compressor relay or W Heating relay
> will energise these relays regardless of the thermostat
> setting. If this does not occur then R is really Gand G
> R. That is the wire to G is really the 24V active and
> the wire to R is from the fan relay.
> However if it does work correctly then the thermostat
> wiring is correct and the fault is in the Indoor Unit
> either the transformer or the wiring. My guess is the
> wiring, perhaps a loose or burnt wire.
> The assumption of course is that the unit worked
> correctly when it was installed.
>
> However it appears that the fault is in the indoor unit
> wiring
>
>
> news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
>
> >I have a puzzling problem. When I select "Cool" on my thermostat, the
> > central fan does not come on, and so, while the air conditioner
> > outside runs, it quickly freezes, as there is no air movement. On the
> > other hand, if I select the heat-cool switch to "Off" and turn the fan
> > "On" the fan works fine. But if while the fan is running, I move the
> > Heat-Cool switch to "Cool" the fan shuts off. I have replace the
> > thermostat, and have the same problem.
>
> > Any help will be greatly appreciated, as the outdoor temperature is
> > now 90F.
OK--when R jumpered to G, A/C unit fan AND indoor central fan
activates. As soon as jumper wire is removed, A/C unit fan stops.
Indoor fan continues operating. (with t'stat switches in "auto" and
"cool".
Telstra
put the wire to the R terminal on G and the wire
to the G terminal on R. and test the thermostat
"randallbrink" <randal...@gmail.com> wrote in message
news:9829f75c-385f-434d...@a9g2000prl.googlegroups.com...
M Q
> I have a puzzling problem. When I select "Cool" on my thermostat, the
> central fan does not come on, and so, while the air conditioner
> outside runs, it quickly freezes, as there is no air movement. On the
> other hand, if I select the heat-cool switch to "Off" and turn the fan
> "On" the fan works fine. But if while the fan is running, I move the
> Heat-Cool switch to "Cool" the fan shuts off. I have replace the
> thermostat, and have the same problem.
>
> Any help will be greatly appreciated, as the outdoor temperature is
> now 90F.
>
>
On many furnaces, the fan speed for A/C is different (and higher) than
the fan speed for heating or for thermostat "Fan". The problem could
well be in the furnace (where your fan is). It could be the higher
speed winding on the motor is open, the connection to that winding
is open, or there is a problem with the relay in the furnace that
controls the fan. Contrary to the diagram on page 16 of the pdf
for the outdoor unit, the "Y" wire often goes to the furnace and is
used by the furnace to turn on the fan and select the speed.
randallbrink
Ah. Yes, this has a true ring to it, because that would explain why
the fan works fine as long as "Cool" is not selected on the thermostat
mode selector.
randallbrink
> On May 18, 7:26 pm, "Telstra" <tfwil...@clear.net.nz> wrote:
>
>
>
> > Cycling the system
>
> > Connecting R 24V Active from the transformer to the
> > G Fan relay Y Compressor relay or W Heating relay
> > will energise these relays regardless of the thermostat
> > setting. If this does not occur then R is really Gand G
> > R. That is the wire to G is really the 24V active and
> > the wire to R is from the fan relay.
> > However if it does work correctly then the thermostat
> > wiring is correct and the fault is in the Indoor Unit
> > either the transformer or the wiring. My guess is the
> > wiring, perhaps a loose or burnt wire.
> > The assumption of course is that the unit worked
> > correctly when it was installed.
>
> > However it appears that the fault is in the indoor unit
> > wiring
>
> > "randallbrink" <randallbr...@gmail.com> wrote in message
>
> >news:eb41b265-aebc-453e...@w1g2000prd.googlegroups.com...
>
> > >I have a puzzling problem. When I select "Cool" on my thermostat, the
> > > central fan does not come on, and so, while theairconditioner
> > > other hand, if I select the heat-cool switch to "Off" and turn the fan
> > > "On" the fan works fine. But if while the fan is running, I move the
> > > Heat-Cool switch to "Cool" the fan shuts off. I have replace the
> > > thermostat, and have the same problem.
>
> > > Any help will be greatly appreciated, as the outdoor temperature is
> > > now 90F.
>
> OK--when R jumpered to G, A/C unit fan AND indoor central fan
> activates. As soon as jumper wire is removed, A/C unit fan stops.
> Indoor fan continues operating. (with t'stat switches in "auto" and
> "cool".
I just wanted to say "Thanks!" to everyone who helped during this
situation. As it turns out, the central fan was incorrectly wired at
the furnace circuit board, and once that was corrected, the air
conditioning now works fine.
I appreciate all the advice.
Mikepier
>
> - Show quoted text -
So how was it incorrectly wired? Did someone else mess with the
furnace?
randallbrink
It was incorrectly wired in that the fan speed switch was wired to
high speed, but the central fan is only single speed. It appeared to
have been wired that way when the unit was installed.