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I have a goodman furnace. Forced air. No a/c. I turn the power on and she starts. Thermostat is off. No wires are crossed that are visible. The pilot does not ignite but the heating element is on. No gas seems to be coming through. Any suggestions? The furnace is only a year and a half old.
Some of the newer furnaces are wired through the circuit board to cut themselves and to go in to a cot out mode for something like 6 hours before it will clear itself and word like it should.
It is rather hard to understand your statement above, you say the furnace starts but you say the thermostat is off. So can you explain a little clearer
The power to the furnace is on the thermostat is off.
I have even tried to disconnect the thermostat. But as soon as I turn the power on whether the thermo is attatched or not, the blower runs, the element gets hot but no gas comes through to finish the ignition.
I am confused. I read in another topic about the blower relay being a similar cause. Any help?
They are notorious for the circuit boards being bad. I'd call a pro...
Okay guys new problem, replaced the board. Main blower is fixed? Now as soon as I power the unit up, the condenser motor starts running and the indicator light blinks three times. What can I change next. Is that the pressure switch indication?Quote:
Originally Posted by wheeloftime
You have something wired wrong if the condenser motor outside starts up. As said before call a pro before you spend too much money on parts trying to fix it.
You may have just connected a wire in the wrong place either at the thermostat or the circuit board. If it follows the conventional color wire it up like this:
Usually there is a 24 volt AC transformer in the furnace with the secondary winding connected to a red wire running to the thermostat and a blue wire, common, to the gas valve, A/C relay, and fan relay. From the thermostat there will be white wire to the gas valve, yellow to the A/C, and green to the fan. The thermostat is wired to switch the power from the red to the white, yellow, and green as needed with the blue completing the circuit. Most thermostats and furnaces have the contacts labeled R, B or C, W, Y, and G for the corresponding wire colors. It may be wired to have the A/C control wires return to the furnace and its controls and then a second wire goes to the A/C unit. Internal wiring may replace the green wire if the thermostat does not give you the option of fan only or continuous fan. Digital or programmable thermostats may need the blue wire connected to them.
To do simple checks like this you do need some tools. A test light, a meter, or a voltage detector might be the best place to start with. I came across the niftiest gadget for trouble shooting, a voltage detector. They work through the insulation of wires. There are several brands. I have a GB Instruments GVD-505A, less than $15 at Home Depot. Touch it to a hot wire, and the end glows red. Find the doodad that lights it on one side, and not the other, and you have the culprit. You do not have to open up housings and expose electrical contacts. You are looking at where your hand is, not where the meter is. Most people are capable of doing repairs and will get it going and not get hurt if they use a little sense. The voltage detector makes it even easier.
Wait a minute! ''the condenser motor starts running ''
The other post confused me. What are you talking about? If you don't have A/C, you don't have an outside condenser. Do you mean the draft inducer motor, a small blower forcing the combustion air through the furnace? Starting it is the first step in a heating cycle. There is a pressure switch that will keep the ignitor from coming on until the inducer is running. Is there a decal on the furnace giving the codes? You might also look for a schematic to see if you have all the wires connected where they should be. If the ignitor came on with the old circuit board, likely the pressure switch is working, but could be incorrectly connected.
Yes your right sorry. Not very good with the proper terms. Yes I checked the wires and they seem to be the same. I took digital pics of the board before I took it off and used it for the basis of reinstalling. I can't find where I went wrong. Jumping it works for the first cycle, if I keep suction to the hose, no wise cracks, it works for the first cycle. The pressure switch isn't working now. Help
Okay here we go. New board new pressure switch. All possible causes according to contractors. Now I get nothing. Board lights up stays solid but nothing. No fan no blower no nothing. I put the old board back on wires in the same position, the blower comes on and the ignitor fires that's it. What am I missing? I'm trying to find my voltmeter o check where my power is and isn't on the new board but in the mean time any suggestions?
You could have a defective new board. It does happen from time to time.
It sounds like you have a hot surface ignitor. A sort of glow plug that directly lights the burners, (no pilot model) How many wires go into the gas valve? If there is only 2 wires plus a ground wire the furnace I describes is what you probably have. Follow these wires back to the circuit board. Are there any devices in-line and ohm out the device, it should read 0-Ohms. Does the circuit board make a small click after the ignitor gets hot? If not it is probably a bad board. Goodman/Janitrol furnaces made with a serpentine heat exchanger design should be safety inspected regularly for broken rivets. The service tech should be able to hand you these broken rings (about the size of a dime) if it is failed. Just so you know if he is telling you the truth. There are allot of sharks in the HVAC business ruining our reputation. I hope this helps.Quote:
Originally Posted by wheeloftime
Okay, lets start with you guys have been a mountain of help!! Secong I have replaced the board the pressure switch and thermostat.. I have to manually (apply suction) to the pressure switch and she runs fine. But if I don't she won't fire. Is there a problem with the draft inducer? It doesn't seem to be providing enough suction to trip the pressure switch. Is there a way to clean it? It was also suggested that there may be moisture in the inducer. Will that cause these symptoms? Other than that she runs. So I think this is the final obstacle to jump.
I think when you said condenser you meant draft inducer blower motor as you already stated there is no A/C. The 3 blink code should be answer by a legend located on the blower door. Probably 1) pressure switch started in the closed position or 2) pressure switch failed to close after inducer started.
Is this 80 or 90% efficient?
LP or NG
It's a 90 % lp
The legend says pressure switch but I replaced it. It is doing the same after replacing the switch. Is there a way to clean the draft inducer. It doesn't seem to be creating enough suction to trip the switch. I can do it manually by applying mild suction to it, I know does not sound right, and while I do that it will fire and run perfect. But on its own the inducer will not trip the pressure switch.
OK that's a good start. Check the port on the inducer motor for obstructions and clean it out with a paper clip. If that doesn't do it you probably have an obstruction in the flue pipe. If this is a 90+ efficient you most likely have a second pipe, the fresh air, that can also be obstructed. I have pulled many birds from flues and inducer motors. If you have to remove the inducer besure to seal it back up good when you put it back on.Quote:
Originally Posted by wheeloftime
How can I tell how old my furnace is
Thank you gentlemen they job is done. It was a blocked inducer vent pipe. Thanks for everything
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