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Posted on Nov 12, 2010

My furnace will not run, LED blinking twice and according to chart this means pressure switch is open....HELP?!

5 Related Answers

Anonymous

  • 254 Answers
  • Posted on Nov 15, 2008

SOURCE: furnace won't kick on

Downstream of your fan discharge there is a little plastic assy. most likely that will have a pickup tube and a piece of vinyl or latex tubing attached. First check to make sure that the pick up tube and/or tubing does not have a restriction. If it is clean use an ohm meter to read resistance across the switch to verify it is operating.

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Anonymous

  • 700 Answers
  • Posted on Dec 25, 2008

SOURCE: Rheem Criterion II Furane would not ignite

what you need to do is take and inspect the hose that goes to the pressure switch and make sure that it is not dry rotted. if it is and the combustion blower is running then firsat try to cut the hose down and slip on a better piece of rubber. If not then replace the hose,

Anonymous

  • 5 Answers
  • Posted on Jan 17, 2009

SOURCE: High limit switch open on armstrong furnace

If you know where the high limit switch is you can always cut the two wires and wire them together causing the limit to close. But what you have to watch out for is why the high limit is not closing. That means in your return air either you have a dirty return air duct, dirty filter, or you don't have all your registors open to allow the heat to escape the heat exchanger. Just watch over riding the system. The high limit switch should either be on or behind the blower, in the middle of the system right under the heat exchanger. any other questions about hvac just ask.

David

Anonymous

  • 77 Answers
  • Posted on Jan 26, 2011

SOURCE: I have an amana dms

Open pressure switch is when your vent motor comes on it has to get a certain vacuum pressure or it won't ignite furnace. There should be some little black hoses connected to vent motor and maybe into heat exchanger, running to these pressure switches. Pull hose off one end and make sure hoses are not kinked or some times if hoses have sag in them they can fill with water. Other causes are if venting is obstructed or pressure switch is defective, especially if it got moisture in it.

Testimonial: "did the trick thanks"

Anonymous

  • 43501 Answers
  • Posted on Sep 10, 2011

SOURCE: Intertherm furnace wont start, LED

Hi,
That means that the exhaust blower is not working properly or the flue piping is plugged...
verify that you have air coming out the exhaust pipe...
Then check the blower that it is working properly...
If this all checks out then replace the pressure switch... they do go bad...

heatman101

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0helpful
1answer

I have an Olsen furnace. It's not running and there is a red light blinking. What's wrong?

Count the blinks in between pauses. On the door of the furnace will be a legend that tells you what that number of blinks mean. For instance 3 blinks may mean open limit switch or pressure switch failed to close, something like that. Post here what it tells you then we can help.
1helpful
1answer

I have a goodman furnace GMP100-4 REV B..about a year ago it was not working. The fan would start but it would not ignite. We found out we need a new ignitor and it was a good quick easy fix. Now a ye

Any light flashin on the control board? If not then look for a small fuse blown on the board. See lights a flashing count them flashes

A sampling of various failure codes on a furnace:

Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. Turn the power off and check the thermostat for improper settings or connections.

Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.

Decipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Turn off the furnace power and repair a short or replace the pressure switch.


Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Check the pressure switch hose of your furnace for blocks or an improper connection. Also, look for blockages in the flue, and tighten any loose wiring.

Translate four LED flashes to mean your furnace has a primary limit circuit open, possibly from loose wiring or blocked filters. Check and clean filters, tighten wiring and check the flue for blockages.

Interpret five LED flashes to mean your furnace senses a flame without a call for heat. This could be from a gas valve closing slowly or a burner flame lingering.



Read seven LED flashes as a warning of a low flame sense microamp signal. This could happen with a coated flame sensor or a lazy flame from poor gas pressure. Turn off the power and adjust the gas pressure according to the information on the rating plate.



See eight LED flashes as meaning an igniter circuit problem due to a bad igniter or an igniter connected improperly. Replace the bad igniter or check the ground wiring, making necessary corrections.



Decipher nine LED flashes to mean the high-stage pressure switch circuit will not close during a high-stage-induced draft blower operation. Your furnace may have a pinched or blocked pressure switch hose, a blocked flue or loose wiring.

Read continuous flashing on the LED to mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram.

If you need further help, reach me via phone at https://www.6ya.com/expert/dan_73bbd84fe1d95b61

1helpful
1answer

I have a Goodman GMP 125-5 furnace. It had a 3 light code i replaced the presure switch now it is giving me a 1 light code please help

A sampling of various failure codes on a furnace:

Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. Turn the power off and check the thermostat for improper settings or connections.

Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.

Decipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Turn off the furnace power and repair a short or replace the pressure switch.


Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Check the pressure switch hose of your furnace for blocks or an improper connection. Also, look for blockages in the flue, and tighten any loose wiring.

Translate four LED flashes to mean your furnace has a primary limit circuit open, possibly from loose wiring or blocked filters. Check and clean filters, tighten wiring and check the flue for blockages.

Interpret five LED flashes to mean your furnace senses a flame without a call for heat. This could be from a gas valve closing slowly or a burner flame lingering.



Read seven LED flashes as a warning of a low flame sense microamp signal. This could happen with a coated flame sensor or a lazy flame from poor gas pressure. Turn off the power and adjust the gas pressure according to the information on the rating plate.



See eight LED flashes as meaning an igniter circuit problem due to a bad igniter or an igniter connected improperly. Replace the bad igniter or check the ground wiring, making necessary corrections.



Decipher nine LED flashes to mean the high-stage pressure switch circuit will not close during a high-stage-induced draft blower operation. Your furnace may have a pinched or blocked pressure switch hose, a blocked flue or loose wiring.

Read continuous flashing on the LED to mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram.
themobilian_3094.jpg

If you need further help, reach me via phone at https://www.6ya.com/expert/dan_73bbd84fe1d95b61

0helpful
1answer

I have goodman GMP series furance the furnance and gas comes on and fires up then goes out flame sensor is good what else could be wrong

Improper ground from control to burner.
Incorrect electrical wiring, check polarity.
Tubing partially clogged between inducer and proving switch.

A sampling of various failure codes on a furnace:

Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. Turn the power off and check the thermostat for improper settings or connections.

Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.

Decipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Turn off the furnace power and repair a short or replace the pressure switch.


Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Check the pressure switch hose of your furnace for blocks or an improper connection. Also, look for blockages in the flue, and tighten any loose wiring.

Translate four LED flashes to mean your furnace has a primary limit circuit open, possibly from loose wiring or blocked filters. Check and clean filters, tighten wiring and check the flue for blockages.

Interpret five LED flashes to mean your furnace senses a flame without a call for heat. This could be from a gas valve closing slowly or a burner flame lingering.



Read seven LED flashes as a warning of a low flame sense microamp signal. This could happen with a coated flame sensor or a lazy flame from poor gas pressure. Turn off the power and adjust the gas pressure according to the information on the rating plate.



See eight LED flashes as meaning an igniter circuit problem due to a bad igniter or an igniter connected improperly. Replace the bad igniter or check the ground wiring, making necessary corrections.



Decipher nine LED flashes to mean the high-stage pressure switch circuit will not close during a high-stage-induced draft blower operation. Your furnace may have a pinched or blocked pressure switch hose, a blocked flue or loose wiring.

Read continuous flashing on the LED to mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram.

If you need further help, reach me via phone at https://www.6ya.com/expert/dan_73bbd84fe1d95b61

1helpful
1answer

Suddenly not working im not sure if there even is a pilot to be lit

Goodman have troubleshooting idiot lights on the board. Look for flashes and count em.
The flash explanations are printed on the backside of the blower cover on most models.
A sampling of various failure codes on a furnace:

Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. Turn the power off and check the thermostat for improper settings or connections.

Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.

Decipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Turn off the furnace power and repair a short or replace the pressure switch.


Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Check the pressure switch hose of your furnace for blocks or an improper connection. Also, look for blockages in the flue, and tighten any loose wiring.

Translate four LED flashes to mean your furnace has a primary limit circuit open, possibly from loose wiring or blocked filters. Check and clean filters, tighten wiring and check the flue for blockages.

Interpret five LED flashes to mean your furnace senses a flame without a call for heat. This could be from a gas valve closing slowly or a burner flame lingering.



Read seven LED flashes as a warning of a low flame sense microamp signal. This could happen with a coated flame sensor or a lazy flame from poor gas pressure. Turn off the power and adjust the gas pressure according to the information on the rating plate.



See eight LED flashes as meaning an igniter circuit problem due to a bad igniter or an igniter connected improperly. Replace the bad igniter or check the ground wiring, making necessary corrections.



Decipher nine LED flashes to mean the high-stage pressure switch circuit will not close during a high-stage-induced draft blower operation. Your furnace may have a pinched or blocked pressure switch hose, a blocked flue or loose wiring.

Read continuous flashing on the LED to mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram.

If you need further help, reach me via phone at https://www.6ya.com/expert/dan_73bbd84fe1d95b61

6helpful
2answers

Bryant furnace plus 90 led code is blinking once then 3 times fast. What does it mean?

these codes are on the inside panel of the front cover of the furnace. lift off and look inside.there should be a code explain chart on the panel by the light. this panel will need to be replace correctly for the furnace to work as there is a door switch.
1helpful
1answer

I have an amana dms 90904cms furnace ..the fan runs but no heat. I opened cover and saw the red led blinking 3 times code says open pressure switch. what does that mean?

Open pressure switch is when your vent motor comes on it has to get a certain vacuum pressure or it won't ignite furnace. There should be some little black hoses connected to vent motor and maybe into heat exchanger, running to these pressure switches. Pull hose off one end and make sure hoses are not kinked or some times if hoses have sag in them they can fill with water. Other causes are if venting is obstructed or pressure switch is defective, especially if it got moisture in it.
0helpful
2answers

Goodman 95 %furnace keeps saying low pressure is stuck. changed out low pressure switch and high pressure switch and still have same problem.

That thang might be sensing a lazy flame. In other words the flames took too long in the board's opinion to quit sensing the flame. Yall probably need to do pressure tap on the gas valve.
Here is a realistic look at goodman fault codes and what to check fer and I am assuming you are not a tech and don't know this already and am hoping it helps:


Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. Turn the power off and check the thermostat for improper settings or connections.

Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.

Decipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Turn off the furnace power and repair a short or replace the pressure switch.


Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Check the pressure switch hose of your furnace for blocks or an improper connection. Also, look for blockages in the flue, and tighten any loose wiring.

Translate four LED flashes to mean your furnace has a primary limit circuit open, possibly from loose wiring or blocked filters. Check and clean filters, tighten wiring and check the flue for blockages.

Interpret five LED flashes to mean your furnace senses a flame without a call for heat. This could be from a gas valve closing slowly or a burner flame lingering.



Read seven LED flashes as a warning of a low flame sense microamp signal. This could happen with a coated flame sensor or a lazy flame from poor gas pressure. Turn off the power and adjust the gas pressure according to the information on the rating plate.



See eight LED flashes as meaning an igniter circuit problem due to a bad igniter or an igniter connected improperly. Replace the bad igniter or check the ground wiring, making necessary corrections.



Decipher nine LED flashes to mean the high-stage pressure switch circuit will not close during a high-stage-induced draft blower operation. Your furnace may have a pinched or blocked pressure switch hose, a blocked flue or loose wiring.

Read continuous flashing on the LED to mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram.

Now here is how it should all go down:



Bottom dollar: it all goes back to type of gas, the initial setup, the pressure tap. and how it is wired up to begin with.
This will give you an idea where to start I hope.

If you need further help, reach me via phone at https://www.6ya.com/expert/dan_73bbd84fe1d95b61

0helpful
1answer

My central heating is on lockout and the burner is with red light

A sampling of various codes on a furnace

Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. Turn the power off and check the thermostat for improper settings or connections.

Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.

Decipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Turn off the furnace power and repair a short or replace the pressure switch.


Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Check the pressure switch hose of your furnace for blocks or an improper connection. Also, look for blockages in the flue, and tighten any loose wiring.

Translate four LED flashes to mean your furnace has a primary limit circuit open, possibly from loose wiring or blocked filters. Check and clean filters, tighten wiring and check the flue for blockages.

Interpret five LED flashes to mean your Goodman furnace senses a flame without a call for heat. This could be from a gas valve closing slowly or a burner flame lingering.



Read seven LED flashes as a warning of a low flame sense microamp signal. This could happen with a coated flame sensor or a lazy flame from poor gas pressure. Turn off the power and adjust the gas pressure according to the information on the rating plate.



See eight LED flashes as meaning an igniter circuit problem due to a bad igniter or an igniter connected improperly. Replace the bad igniter or check the ground wiring, making necessary corrections.



Decipher nine LED flashes to mean the high-stage pressure switch circuit will not close during a high-stage-induced draft blower operation. Your furnace may have a pinched or blocked pressure switch hose, a blocked flue or loose wiring.

Read continuous flashing on the LED to mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram.

If you need further help, reach me via phone at https://www.6ya.com/expert/dan_73bbd84fe1d95b61

0helpful
1answer

Rheem Criterion II Furane would not ignite

what you need to do is take and inspect the hose that goes to the pressure switch and make sure that it is not dry rotted. if it is and the combustion blower is running then firsat try to cut the hose down and slip on a better piece of rubber. If not then replace the hose,
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