Question about Goodman GMS90703BXA Heater

1 Answer

Shutting off on pressure sw. 2 yr old goodman counter flow 80+

Unit in closet question whether switch is bad or blockage in flue or elsewhere. The inducer blower seems to be fine.
What should pressure be at inducer or switch?

Posted by on

  • Anonymous Mar 27, 2014

    Open pressure switch no power going to inducer motor


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert who has written 7 tips or uploaded 3 video tips

  • Master
  • 462 Answers

The problem is your gettign a code and the legend is telling you its the pressure switch? From your description.

Well it is going to be rather difficult for you to check the switch without a .10" gauged water manometer gauge. It would be easier and cheaper for you to purchase another switch but if its only 2 years old the factory warranty is usually 5 years on parts. All you'd owe for is labor and freight if you have to have it sent to you. Take your model and seril no and go to who you purchased iot from and tell them what code your getting.

Some of these pressure switches and the boards that control them look for the switch to acuate both ways on and off knowing that the switch is actually working and not stuck. So you could start out by jumping the correct NC normally closed circut turn on the furnace and remove this jumper and then close the NO normally closed circut with a jumper. This isnt a fix but may help you see if the switch is actually at fault. If you get it to lite off let it cycle back off and note if it works all way through the cycle. If it does Your problem is most likely the switch because you just did all it does only by hand. DO not leave it this way because you can cause a more seveer problem and it is can develope dangerious consequences. This is just 1 way to check the switch. Another way is to check it electrically. If your femilur with open and closed circuts check across the closed and open circut whith it off then with it running and (if it has 3 terminals wires in, if it just has 2 wired in then it is not going to look for one of the operations Ive discribed). And then check and see if the voltages reverse while beginnign to lite off. If it does reverse Im betting you have a different problem and the swich is what the board has been told is giving the trouble.

Hope this is clear. If not get back to me. If it helps please grade me accordingly. THANK you and GOOD LUCK

Posted on Mar 04, 2009

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

System lockout

One thing to try is, shutting down the direct power to the unit for approximately 5 minutes, then turn the power back on and retry the unit by turning up the temp on the thermostat, this normally resets the circuit board in the unit. If the problem still continues, you may be having trouble with the pressure switch, also check to see if there is a blockage of the air intake, such as a bees nest, or if you are where there is a lot of snow or ice this will also cause blockage of the air intake and must be cleared for proper operation, and will affect the pressure switch as well. Hope this helps !!!!

Nov 05, 2013 | Goodman GMS90703BXA Heater

1 Answer

Furnace problems

On - OK
1 Blink - Ignition failure. Check Gas flow, gas pressure, gas valve, flame sensor.
2 Blinks - Closed pressure switch. Check pressure switch (stuck in closed position).
3 Blinks - Pressure switch - failre to close. Check venter, pressure switch, vent blockage.
4 Blinks - Open limit switch. Main limit or aux limit are open. (My comment - Means overheating in chamber. Often result of blocked intake air. Bad filter. In my case, plastic wrap had been sucked into the intake. )
6 Blinks - False flame sensed. Check sticking gas valve.
Rapid continuous blinking - Incorrect twinning, incorrect primary polarity. Reverse transformer secondary leads, reverse primary wires.

Closed pressure switch can be from dirty combustion vents, bad chamber pressure - like missing screws, maladjusted gas pressure, failing pressure switch, loose hoses, moisture in the hoses or fan blades The switch need to be closed to ge the unit to work

Jan 23, 2008 | Goodman GMS90703BXA Heater

1 Answer

Replaced pressure switch, ventor and unit still goes off on pressure switch. 3 flashes

Hello, check the small tubing that goes from the pressure switch to the inducer motor, sometimes it could be loose or blocked therfore not allowing the switch to close. Also, there could be some obstruction in the flue pipe preventing the switch from closing.

Jan 26, 2011 | Goodman GMS90703BXA Heater

1 Answer

My furnace will not light. What does it mean when the red light on the circut board flashes 3 times?

Hello, a 3 flash on a circuit board means that a pressure switch is open, this could be due to a blockage in the flue pipe or the small tubing that goes from the inducer to the pressure switch is loose, leaking, or is blocked. You can try taking the tubing out and checking if there is anything in it blocking the pressure between the pressure switch and inducer motor and then attaching back on and make sure it's secure and tight. If that does not work that the switch itself is bad and must be replaced.

Jan 22, 2011 | Goodman GMS90703BXA Heater

2 Answers

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.

Dec 10, 2010 | Goodman GMS80903BNA Heater

1 Answer

New gmh95/gch9 system. getting a diag. code 3 flashes, [pressure switch area]. all flues clear, hoses clear,drain lines working. left side down application and i just installed kit #000143- flue drain ....

I like the unit.How new?Check the pitch/tilt of flues they cant sag or haue dip/low spots.How many 90degree elbows on exaust pipe?Approxmately how/long many feet is pipe?

Mar 27, 2010 | Goodman Heaters

1 Answer

Goodman heater not turning on

If your pressure switch is clogging then you need to check the flue pipe make sure it is not rusting. If it is the flue should be replaced and also think about replacing the pressure switch. Check your high limit switch also. If the pressure switch goes sometimes it pops the high limit

Feb 12, 2009 | Goodman GMS90703BXA Heater

1 Answer

Heater wont start

does inducer motor come on?motor will be right below flue pipe inlet.if so make sure pressure switch closes.pressure switch tube could be kinked.also make sure furnace has good ground.sometimes not being grounded will cause this

Dec 31, 2008 | Goodman GMS90703BXA Heater

2 Answers

Furnace won't stay running

Furnace fails to operate.
• Integrated control module
diagnostic LED is
flashing ONE (1) flash.
• Furnace lockout due
to an excessive
number of ignition
“retries” (3 total)1.
• Failure to establish flame.
Cause may be no gas to
burners, front cover
pressure switch stuck open,
bad igniter or igniter
alignment, improper orifices,
or coated/oxidized or
improperly connected flame
• Loss of flame after establishment.
Cause may be
interrupted gas supply, lazy
burner flames (improper gas
pressure or restriction in flue
and/or combustion air
piping), front cover pressure
switch opening, or improper
induced draft blower
• Locate and correct gas
• Check front cover
pressure switch
operation (hose, wiring,
contact operation).
Correct if necessary.
• Replace or realign
• Check flame sense
signal. Sand sensor if
coated and/or oxidized.
• Check flue piping for
blockage, proper
length, elbows, and
• Verify proper induced
draft blower performance.

Nov 23, 2008 | Goodman GMS90703BXA Heater

4 Answers

Goodman code problem three blinks

Same problem with 1 yr old Goodman. Checked entire exhaust and pressure switch. Inside fan, pressure switch hose clogged with crusty white gunk. Cleaned it & furnace fixed. I have no furnace repair experience, but love to "play MacGyver". Hopefully this could save someone a service call.

Sep 18, 2007 | Goodman GMS90703BXA Heater

Not finding what you are looking for?
Goodman GMS90703BXA Heater Logo

110 people viewed this question

Ask a Question

Usually answered in minutes!

Top Goodman Heaters Experts


Level 3 Expert

1901 Answers

Dan Webster
Dan Webster

Level 3 Expert

8147 Answers

Ken Thomas

Level 2 Expert

118 Answers

Are you a Goodman Heater Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides