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    akl5q's Avatar
    akl5q Posts: 3, Reputation: 1
    New Member
     
    #1

    Oct 11, 2006, 07:58 PM
    I have AC, but no heat... Is the problem my furnace?
    At first, my motor fan would cut off. After replacing the fuses, it kicked back on and I had cool AC. Later down the line, I noticed frost on the pip leading from the furnace to the motor fan. I purchased some insulating tape and called it a day. It seemed to keep it from freezing. Now, I tried to put my thermostat to the heat setting and it's spitting out COLD air!! Not what I wanted. Is something wrong with my furnace? The pilot light for the water heater is on... (I don't know if this is linked to my central air) If so, how do I fix it? If not, what could it be?
    The WB's Avatar
    The WB Posts: 78, Reputation: 6
    Junior Member
     
    #2

    Oct 11, 2006, 10:29 PM
    If you have a heat pump system, your system may be low on refrigerant. Do you have a gas furnace. Is your gas on?
    labman's Avatar
    labman Posts: 10,580, Reputation: 551
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    #3

    Oct 12, 2006, 05:22 AM
    We must know what sort of a system you have. Is it the usual gas forced air with an A/C coil? If you have a gas hot water heater, I would be surprised if you have a heat pump, the outside unit up on legs. Post back giving all the details you can.
    akl5q's Avatar
    akl5q Posts: 3, Reputation: 1
    New Member
     
    #4

    Oct 12, 2006, 05:24 AM
    I believe I do have a gas furnace. My gas bill is extremely low now that I do not use my heat nor cooling air. The pilot under the water heater is on. If there is a separate pilot for the AC, I do not know where it is located.

    I know that my system is made by RUUD. I have no paperwork on my Central Air System. If I retrieve a special order number off the label will that tell me what type of system it is or should it say so on the equipment?


    So why would I be low on refrigerant? I thought that it was a closed loop system.. How could it escape and if I am low, will it escape again for another chance to refill it? Thanks a lot for responding this morning, WB.
    The WB's Avatar
    The WB Posts: 78, Reputation: 6
    Junior Member
     
    #5

    Oct 12, 2006, 08:46 AM
    Sometimes the copper tubing can become brittle over time. The brazed connections can crack at the valves or in the line. Brass fittings can be over tightened, which will cause a leak. The valves could be leaking. It could be a slow leak that occurs over a long time or a short time. The coils at the furnace may have a leak. The ice on the line means there is some sort of problem.
    If can you get your hands on a "sniffer" or a leak detection device. Take insulation off the line and run the sniffer down the line. It should detect the leak. Depending on the age of the system, the refirgerant could be old.
    You will have to have a professional recharge the system unless you have a license to handle refrigerant.
    I don't think many newer furnaces have pilot lights anymore. You may have an electronic ignition. In most cases, that is a simple fix.
    labman's Avatar
    labman Posts: 10,580, Reputation: 551
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    #6

    Oct 12, 2006, 10:21 AM
    If you have a gas furnace, forget about refrigerant until the next A/C season.

    In newer gas furnaces, when the thermostat switches power to the white wire from the thermostat, the small draft blower starts, the ignitor heats up, the gas comes on and lights, and then the blower starts up before long. You have a circuit board with relays on it and some logic chips. There are sensors in the furnace that check each step of start up. Nothing should happen until the sensors verify proper operation of the last step. If anything fails, the furnace should shut down and start over again in a few minutes.

    All that is hard to check. All the wiring is inside the furnace. When you remove the panel, it opens a switch shutting power off. What you can do, is set the thermostat on heat and the dial turned up high enough for the furnace to come on. Then remove the panel, the one that covers the filters. With the panel off, find the switch and hold it in with your hand. See if a small blower comes on, followed by a little doodad getting red hot, and the gas coming on. What you have to do is identify the step that isn't working. If the small blower doesn't start up, you need to identify the wire feeding it, and see if it is hot. If it is, and the motor doesn't run, the motor is bad. Making it harder is that only one of maybe 6 wires to the motor should be hot.
    Just keep checking things until you find what isn't working.

    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.

    With the blower coming on without the heat, it sounds like you could have more than one problem. Likely at least one of them is on the circuit board. When the fuses blew, something may have been damaged. Also a lightening strike over the summer could have damaged the heating circuit. Circuit boards are expensive, and you must have the model mummer of the furnace. They aren't that hard to change if you can mark wires and where they came off, and then put them back on correctly. If you don't find something simple such as a lose wire, you might be better off calling a technician.
    carmelomorales4's Avatar
    carmelomorales4 Posts: 1, Reputation: 1
    New Member
     
    #7

    Nov 12, 2009, 06:25 AM

    The ignitor flamerod is not working all the limit in the system are good. Can you help me. It is a rheem furance
    KC13's Avatar
    KC13 Posts: 2,556, Reputation: 99
    Ultra Member
     
    #8

    Nov 12, 2009, 07:53 PM
    Check status LED, if present. If you have a voltmeter, disconnect ignitor plug and check for 120v with furnace running. If voltage is present but ignitor does not glow, carefully remove and inspect ignitor.

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