On 24 Dec 2004 20:23:48 -0800, wrote:


wrote:
My son has a Bryant furnace about 10 years old. Within the past 2
weeks started having an intermittent problem. The furnace doesn't
always recycle on after being off. He's replaced both the thermostat
(Honeywell) and now the igniter. Sometimes it comes back on like it
is
suppose to, other times (especially at night), it doesn't. When it
doesn't come on, there is nothing -- no blower, no flame, nothing.

Any suggestions.

He recently had a new baby so money is tight.

Shirley

Thanks to most who have tried to answer my question.

I should mention this is a gas furnace. Maybe I'm not using the right
terminology -- with igniter. This furnace does not have a pilot light.
It has electronic ignition that starts the furnace when needed.

I guess I don't quite understand some of the answers I received -- like
where does he get his fuel? It's all natural gas.
Merry Christmas.

Shirley


There are several things that can cause a hard lockout. Here are a
couple easy ones:

Change the air filter. If the furnace doesn't get enough airflow it
can overheat and lockout.

On the opposite side of the burner from the ignitor is a flame sensor.
This is a ceramic/steel rod. The flame hits the steel portion and this
tells the control board that the burner is working. If it fails to
"see" the flame after three attempts at ignition, it will lockout.
Remove the flame sensor and clean the steel portion with steel wool.

If these don't do it, call someone.

Hmmmmm... why does everyone change the thermostat first? That's like
replacing the switch if a light doesn't work. It's the least likely
problem.

_______________

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
Written by a veteran Service Technician

https://www.merchantamerica.com/tmethod/