SOURCE: gas furnace, main burner ignites the other 2 don't. then shutdn.
Between the burners is a small rail in the pressed steel where the flame runs across to light the other burners and it sounds like there is dirt or debris in the step over rails causing the problem. You will need to use some compressed air on those rails to clear them out. Once the rails are clear the other two burners should ignite right away.
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SOURCE: RUUD Ultra 90 Plus Modulating up flow furnace
Sounds like the cross over between the burners are to tight. I would take a common screwdriver and open the slot just a little. Only other thing I am worried about is the gas pressure on the burner side. Needs to be set as per installation manual.
SOURCE: carrier furnace ,burner not staying on after 4th
Remove them and scrub them with a wire brush.
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 igniter. The igniter will glow and you will be able to see it if viewed thru the small inspection port. Once the igniter 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 igniter does not energize (bad control, bad igniter), the gas valve does not open or there is no gas (bad gas valve, broken wire, no gas), the pilot does not light (dirty pilot), the burner does not light (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).
SOURCE: i have a rudd hot air gas furnace,ignitor sparks
to carmelmontgo; do you have a smart gas valve sometimes the wire connections get loose. remove wire connector then reinstall. also cleaning a flame sensor will work if the flame sensor is good. I would check the ground connection sometimes contaminated with rust. also I would check the gas pressure with a gas manometer...my email is [email protected]
SOURCE: What would cause a furnace
You could have plugged orfices in the line coming out of the gas valve. Next you could have a plugged gas regulator.The only way your going to find this out is to check gas pressure before the gas valve during a call for heat and then check it after the gas valve during a call for heat you could have a bad gas valve. Try this let me know what you find Thanks and please leave feedback
Hi,
Check the flame sensor and/or the grounding from the burner ot the ignition control....it is not sensing the flame...
Here is a tip that will help you try to figure out why your furnace is not working.
Basic Furnace or Heating System Troubleshooting
heatman101
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