Question about Goodman GMS90703BXA Heater
My GMP075-3 will start and fire for about 1-2 minuites then the gas valve will close and the unit will not restart. When I test voltage accross the valve and it read 0. So I powered down the furnace reset all 4 roll out switches, turned the power back on and the gas valve opened and the furnace fired up. Again within 1-2 minuites the gas valve closed. I also disconnected all but one of the roll out switches and bypassed the rest and the same problem occured. I tried this with each of the 3 switches directly connected to the combustion box and every time it failed. Therefore I believe I am overheating the combustion box and tripping the roll out switches. Any ideas for the over heating?
Sequence of operation, Gas Furnace.
On a call for heat, the 24 volt thermostat sends a signal to the control module. The control module will indicate a call for heat with a light on the control either blinking or remain solid depending upon model. The inducer (exhaust) blower will purge all gasses from the furnace and pressurize a pressure switch. Once the pressure switch tells the module to continue, the electronic ignition will energize and send 120 volts to the ignitor. The ignitor will glow and you will be able to see it if viewed thru the small inspection port. Once the ignitor gets hot enough, it sends a signal to the module opening up the gas valve (24 volts). Either a pilot will come on or the burner tube will ignite then spread the flame to all burners. Lastly a safety sensor will be looking for a certain temperature within a few seconds and the furnace will continue to operate and the room air blower will turn on in a minute or two.
What could go wrong? The unit will not run if there is no signal from the thermostat (bad thermostat or broken wire), the control module does not sense a signal from the thermostat (bad control), the inducer does not energize (bad motor), the pressure switch does not close (blocked vent piping, bad switch, plugged condensate hose), the ignitor does not energize (bad control, bad ignitor), the gas valve does not open or there is no gas (bad gas valve, broken wire, no gas), the pilot does not lite (dirty pilot), the burner does not lite (bad burner, plugged orifice, not enough combustion air), the flame does not spread to each burner (bad flame spreader, dirty flame spreader, more bad burners), the flame safety sensor does not detect flame (dirty or bad flame spreader, bad flame sensor, broken wire, bad control), or the room air blower does not energize (bad fan motor, bad control).
Most newer furnaces will have a diagnostic center or control built into the control module. You may be able to view it as it is running thru a small viewing port. Some models will require the removal of an access panel prior to finding it. On the reverse of the access panel, there will be a diagnostic chart that will aide you in understanding any error code recorded (usually a blinking light).
This is why we technicians earn the big bucks!
Posted on Dec 04, 2008
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Feb 10, 2011 | Coleman Propane Forced Air Heater...
1. Thermostat calls for heat. 2. Draft inducer motor starts. 3. Pressure switch attached by a small plastic or rubber tube senses the negative pressure produced by the draft inducer and closes. 4. Draft inducer runs for 30 seconds to a minute before you hear a gas hissing sound. The ignitor did not glow, the flame sensor (a small metal probe about 1/8" in diameter, with a white porcelain base) does not sense the flame, so after 8 to 10 seconds the hissing sounds stops with no ignition of gas to heat your home. Your furnace shuts down and goes into a lock out condition until you turn your power switch back off and on again. Then the sequence starts all over again with no ignition of the gas. Solution:You probably need to purchase and install a new ignitor. I would suggest that you inspect your ignitor closely for cracks. Make sure you do not touch the ignitor with your bare hands. If you do not visually see a crack, then you could have a furnace control board problem or a limit, rollout switch problem. The furnace's control board might not be supplying the voltage to the ignitor. If your furnace lights and the gas stays on for 8 to 10 seconds, then shuts right back off, then you need to clean your flame sensor with light sand paper or steel wool. You might need a new flame sensor, but most of the time they can be cleaned an will work well after cleaning.
Dec 07, 2010 | Heating & Cooling
Oct 21, 2010 | Honeywell Heating & Cooling
Aug 03, 2010 | Raypak Free Hydraulic Lift Gate Delivery -...
Apr 10, 2010 | Heating & Cooling
Dec 28, 2009 | Goodman GMS90703BXA Heater
Oct 27, 2009 | Cross Furnace Draft Inducer Blower 115...
Oct 16, 2009 | York Furnace Draft Inducer Blower Fasco #...
Oct 16, 2009 | Goodman GMS90703BXA Heater
Jan 23, 2008 | Goodman GMS90703BXA Heater
1,409 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: