I have an Amana GHN90A50 furnace (circa 1987) that has an ignition
problem: I will occasionally notice the house is cold, with the temp
well below the setting on the thermostat. When I check the furnace,
the blower is running, the ignitor is glowing but no ignition. If I
then set the thermostat lower than the room temp, the blower and
ignitor shut off. I wait a few seconds (which I guess allows the
furnace to reset) and raise the temp on the thermostat. Then
everything is fine: the blower and ignitor come on and the burners
ignite.

I have a suspicion that this only happens (and then, only
occasionally) when we set the thermostat low for the night (60 or 61
degrees) but I have not tested this theory. Strangely, our tenants in
a house we rent had the same problem with a new furnace we installed
there a year ago; they set it low (maybe 55 degrees) because they were
out for a few days and found that the furnace didn't ignite.

Any suggestions?

On Jan 20, 9:37*pm, rocketman wrote:
I have an Amana GHN90A50 furnace (circa 1987) that has an ignition
problem: I will occasionally notice the house is cold, with the temp
well below the setting on the thermostat. *When I check the furnace,
the blower is running, the ignitor is glowing but no ignition. *If I
then set the thermostat lower than the room temp, the blower and
ignitor shut off. *I wait a few seconds (which I guess allows the
furnace to reset) and raise the temp on the thermostat. *Then
everything is fine: the blower and ignitor come on and the burners
ignite.

I have a suspicion that this only happens (and then, only
occasionally) when we set the thermostat low for the night (60 or 61
degrees) but I have not tested this theory. *Strangely, our tenants in
a house we rent had the same problem with a new furnace we installed
there a year ago; they set it low (maybe 55 degrees) because they were
out for a few days and found that the furnace didn't ignite.

Any suggestions?

Wierd, usually the blower should not come on unless the chamber or
duct reaches a certain temp. Sounds like something faulty with the
circuit or control board.

rocketman wrote:
I have an Amana GHN90A50 furnace (circa 1987) that has an ignition
problem: I will occasionally notice the house is cold, with the temp
well below the setting on the thermostat. When I check the furnace,
the blower is running, the ignitor is glowing but no ignition. If I
then set the thermostat lower than the room temp, the blower and
ignitor shut off. I wait a few seconds (which I guess allows the
furnace to reset) and raise the temp on the thermostat. Then
everything is fine: the blower and ignitor come on and the burners
ignite.

I have a suspicion that this only happens (and then, only
occasionally) when we set the thermostat low for the night (60 or 61
degrees) but I have not tested this theory. Strangely, our tenants in
a house we rent had the same problem with a new furnace we installed
there a year ago; they set it low (maybe 55 degrees) because they were
out for a few days and found that the furnace didn't ignite.

Any suggestions?

I do not know what tools you have or what your capabilities are, but I
would hang a volt meter across the valve coil terminals to see if the
24v AC is being applied when heat was being called for. That will tell
you much about your problem.

On Jan 21, 8:13*am, Ken wrote:
rocketman wrote:
I have an Amana GHN90A50 furnace (circa 1987) that has an ignition
problem: I will occasionally notice the house is cold, with the temp
well below the setting on the thermostat. *When I check the furnace,
the blower is running, the ignitor is glowing but no ignition. *If I
then set the thermostat lower than the room temp, the blower and
ignitor shut off. *I wait a few seconds (which I guess allows the
furnace to reset) and raise the temp on the thermostat. *Then
everything is fine: the blower and ignitor come on and the burners
ignite.

I have a suspicion that this only happens (and then, only
occasionally) when we set the thermostat low for the night (60 or 61
degrees) but I have not tested this theory. *Strangely, our tenants in
a house we rent had the same problem with a new furnace we installed
there a year ago; they set it low (maybe 55 degrees) because they were
out for a few days and found that the furnace didn't ignite.

Any suggestions?

* * * * I do not know what tools you have or what your capabilities are, but I
would hang a volt meter across the valve coil terminals to see if the
24v AC is being applied when heat was being called for. *That will tell
you much about your problem.

The furnace is running right now and I just checked the coil: yes,
it's got 24v across it (obviously, since it's working).
The next time the furnace won't light I'll re-check the coil. So
let's say it has no or low voltage then, what's the likely culprit?

On Jan 20, 9:37�pm, rocketman wrote:
I have an Amana GHN90A50 furnace (circa 1987) that has an ignition
problem: I will occasionally notice the house is cold, with the temp
well below the setting on the thermostat. �When I check the furnace,
the blower is running, the ignitor is glowing but no ignition. �If I
then set the thermostat lower than the room temp, the blower and
ignitor shut off. �I wait a few seconds (which I guess allows the
furnace to reset) and raise the temp on the thermostat. �Then
everything is fine: the blower and ignitor come on and the burners
ignite.

I have a suspicion that this only happens (and then, only
occasionally) when we set the thermostat low for the night (60 or 61
degrees) but I have not tested this theory. �Strangely, our tenants in
a house we rent had the same problem with a new furnace we installed
there a year ago; they set it low (maybe 55 degrees) because they were
out for a few days and found that the furnace didn't ignite.

Any suggestions?

sounds like a bad ignitor, when the last time the furnace was serviced?

These are all valid suggestions for troubleshooting, but I'm still
puzzled why the blower comes on if there is no flame?

rocketman wrote:
On Jan 21, 8:13 am, Ken wrote:
rocketman wrote:
I have an Amana GHN90A50 furnace (circa 1987) that has an ignition
problem: I will occasionally notice the house is cold, with the temp
well below the setting on the thermostat. When I check the furnace,
the blower is running, the ignitor is glowing but no ignition. If I
then set the thermostat lower than the room temp, the blower and
ignitor shut off. I wait a few seconds (which I guess allows the
furnace to reset) and raise the temp on the thermostat. Then
everything is fine: the blower and ignitor come on and the burners
ignite.
I have a suspicion that this only happens (and then, only
occasionally) when we set the thermostat low for the night (60 or 61
degrees) but I have not tested this theory. Strangely, our tenants in
a house we rent had the same problem with a new furnace we installed
there a year ago; they set it low (maybe 55 degrees) because they were
out for a few days and found that the furnace didn't ignite.
Any suggestions?
I do not know what tools you have or what your capabilities are, but I
would hang a volt meter across the valve coil terminals to see if the
24v AC is being applied when heat was being called for. That will tell
you much about your problem.

The furnace is running right now and I just checked the coil: yes,
it's got 24v across it (obviously, since it's working).
The next time the furnace won't light I'll re-check the coil. So
let's say it has no or low voltage then, what's the likely culprit?

You need to back up to where the 24v comes from. It probably is going
to a control board, but you must follow the leads. Such a problem could
be as simple as a poor connection.

If the voltage IS there at the valve and it fails to open, it could
well be a bad valve. I have had a couple valves where the coil winding
on the valve opened up causing such a problem. You can check for such a
problem by removing one of the wires going there and measuring the coil
resistance with an ohm meter. Keep in mind however that your connection
could be intermittent. Hang the ohm meter leads securely across the
coil and tap the valve with the handle of a screwdriver. If it
momentarily opens up, that is your problem.

On Jan 21, 11:10�am, Mikepier wrote:
These are all valid suggestions for troubleshooting, but I'm still
puzzled why the blower comes on if there is no flame?

burner likely turns on, then off quickly

On Wed, 21 Jan 2009 07:27:07 -0800 (PST), "
wrote:

On Jan 20, 9:37?pm, rocketman wrote:
I have an Amana GHN90A50 furnace (circa 1987) that has an ignition
problem: I will occasionally notice the house is cold, with the temp
well below the setting on the thermostat. ?When I check the furnace,
the blower is running, the ignitor is glowing but no ignition. ?If I
then set the thermostat lower than the room temp, the blower and
ignitor shut off. ?I wait a few seconds (which I guess allows the
furnace to reset) and raise the temp on the thermostat. ?Then
everything is fine: the blower and ignitor come on and the burners
ignite.

I have a suspicion that this only happens (and then, only
occasionally) when we set the thermostat low for the night (60 or 61
degrees) but I have not tested this theory. ?Strangely, our tenants in
a house we rent had the same problem with a new furnace we installed
there a year ago; they set it low (maybe 55 degrees) because they were
out for a few days and found that the furnace didn't ignite.

Any suggestions?

sounds like a bad ignitor, when the last time the furnace was serviced?

NOT likely to be a bad ignitor, as it is glowing, trying to light gas
that, apparently, is not there.

On Wed, 21 Jan 2009 10:28:14 -0800 (PST), "
wrote:

On Jan 21, 11:10?am, Mikepier wrote:
These are all valid suggestions for troubleshooting, but I'm still
puzzled why the blower comes on if there is no flame?

burner likely turns on, then off quickly
Either that or the controller starts the fan after a fixed delay any
time the burner is "turned on " (whether actually burning or not) as a
fail-safe to protect against a high-limit failure.

"Mikepier" wrote in message
...
These are all valid suggestions for troubleshooting, but I'm still
puzzled why the blower comes on if there is no flame?

I thought maybe the OP was referring to the draft inducer rather than the
main blower. Or maybe the control is in a lockout mode which runs the main
blower.

Don Young

On Jan 21, 9:28*pm, "Don Young" wrote:
"Mikepier" wrote in message

...

These are all valid suggestions for troubleshooting, but I'm still
puzzled why the blower comes on if there is no flame?

I thought maybe the OP was referring to the draft inducer rather than the
main blower. Or maybe the control is in a lockout mode which runs the main
blower.

Don Young

pull flame sensor ( turn thermostat down first or turn the heat
totally off, then unplug flame sensor lead from control board, unscrew
sensor) then clean it with steel wool - it worked for me few days
ago

On Jan 21, 10:30*pm, wrote:
On Jan 21, 9:28*pm, "Don Young" wrote:

"Mikepier" wrote in message

....

These are all valid suggestions for troubleshooting, but I'm still
puzzled why the blower comes on if there is no flame?

I thought maybe the OP was referring to the draft inducer rather than the
main blower. Or maybe the control is in a lockout mode which runs the main
blower.

Don Young

pull flame sensor ( turn thermostat down first or turn the heat
totally off, then unplug flame sensor lead from control board, unscrew
sensor) then clean it with steel wool - it worked for me few days
ago

I'll try this. But What are you saying is wrong? That the flame
sensor is somehow keeping the valve from opening and letting gas flow?

On Jan 21, 9:28*pm, "Don Young" wrote:
"Mikepier" wrote in message

...

These are all valid suggestions for troubleshooting, but I'm still
puzzled why the blower comes on if there is no flame?

I thought maybe the OP was referring to the draft inducer rather than the
main blower. Or maybe the control is in a lockout mode which runs the main
blower.

Don Young

I think it is the main blower that is running. What might cause the
controller to go into lockout mode?

On Jan 22, 12:29*am, rocketman wrote:
On Jan 21, 9:28*pm, "Don Young" wrote:

"Mikepier" wrote in message

....

These are all valid suggestions for troubleshooting, but I'm still
puzzled why the blower comes on if there is no flame?

I thought maybe the OP was referring to the draft inducer rather than the
main blower. Or maybe the control is in a lockout mode which runs the main
blower.

Don Young

I think it is the main blower that is running. *What might cause the
controller to go into lockout mode?

I thought lockout mode shuts down everything, including the blower,
and must be reset manually.

"rocketman" wrote in message
...
On Jan 21, 9:28 pm, "Don Young" wrote:
"Mikepier" wrote in message

...

These are all valid suggestions for troubleshooting, but I'm still
puzzled why the blower comes on if there is no flame?

I thought maybe the OP was referring to the draft inducer rather than the
main blower. Or maybe the control is in a lockout mode which runs the main
blower.

Don Young

I think it is the main blower that is running. What might cause the
controller to go into lockout mode?

The control board generally has a light which blinks a code indicating the
reason for the lockout. Controls go into lockout and require manual reset
when an unsafe condition is recognized. Often the control will retry several
times before locking out. The main blower might be left running if the
lockout was due to an over-temperature condition during the last cycle.

Don Young

Don Young wrote:
"rocketman" wrote in message
...
On Jan 21, 9:28 pm, "Don Young" wrote:
"Mikepier" wrote in message

...

These are all valid suggestions for troubleshooting, but I'm still
puzzled why the blower comes on if there is no flame?
I thought maybe the OP was referring to the draft inducer rather than the
main blower. Or maybe the control is in a lockout mode which runs the main
blower.

Don Young

I think it is the main blower that is running. What might cause the
controller to go into lockout mode?

The control board generally has a light which blinks a code indicating the
reason for the lockout. Controls go into lockout and require manual reset
when an unsafe condition is recognized. Often the control will retry several
times before locking out. The main blower might be left running if the
lockout was due to an over-temperature condition during the last cycle.

Don Young


Hi,
If blower keeps running high limit sensor opened and not closing even
after cooling. I just had that problem last week. high limit switch was
open and never closed even after cooling down. As a result blowr was
running on and on. I removed sensor and gently tapped it and it closed.
I ordered a replacement but since furnace has been running OK. As simple
as dirty filter can trigger high limit sensor.

Some furnace, the blower comes on a certain time after the
burner. Other furnace, the blower comes on based on the
temperature of the heat exchanger.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Mikepier" wrote in message
...
These are all valid suggestions for troubleshooting, but I'm
still
puzzled why the blower comes on if there is no flame?

pabas wrote:
pabas had written this in response to
http://www.thestuccocompany.com/main...te-355098-.htm
:

Did the answer posted on this thread


Another idiot post to a 13 month old thread from the sucko company.

You are posting to a usenet newsgroup. The sucko company is a parasite.

rocketman has not appeared in the last 5 weeks on my newsreader.