The thermostat is set for 'HEAT.' When I turn my furnace on, the burner starts, runs for five sec then turns off and repeats the same cycle for four times. Then after the fourth time the main blower starts and run non-stop blowing cold air and the burner never goes on again. it's not reacting on the thermostat settings, just blows untill I manuly turn it off.
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Re: York Dianond 80 Furnace
You have a limit switch that needs to be reset. It is probably the roll out switch that is located on the burner housing. The limit switch is a disk about the size of a dime or penny and has two wires to it. There is a small button in the middle of these two wires. Press this button firmly to reset it. Look for all the limits that may be on the unit that is manual reset like the one described above and do the same. This should correct your problem.
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Oct 26, 2013 - i have a gas furnace with a lit pilot, but the burners won't light. ... if the thermocouple does not sense the heat of the pilot it prevents the gas controller fromturning on the burners. ... clamped onto the outgoing hot water pipe, if huydronic system) that is telling the furnace it is too hot, whether or not that is true.
wireless thermo has 2 units - room thermo and furnace rcvr.
if thermo is battery powered no wires to connect - if not needs 24V connected - then why do they call it wireless?
rcvr connects to same 4 wires as current therm except at the furnace - 24v power and 2 control lines
I can't remember the color code except red/black is +24v/common
but I have found them messed up by "professional" installers so u need to verify before connecting or go by the terminal labeling.
I take it you are in a new (to you) house. Sounds like you have "tankless" hot water, which means the same burner that heats the house also heats the hot water for your sinks and shower. So as a minimum, yes the power to the furnace must be on, but that doesn't mean you have to heat the house. You can turn down the thermostat and leave the power to the furnace "on". To save a few bucks, turn it off when you go away for the weekend, or even for the day, the response time to heat it up is usually pretty fast.
Sounds like it could be a dirty or bad flame sensor.
When the burner lights ,there is a flame sensor in the flame and it is suppose to sense the flame and send a signal back to the control board which will keep the gas valve open, if it gets dirty or is bad it doesn't send the signal back to the board and the board will shut the gas valve off and after three tries it will lock out the furnace and you have to reset it to get it to work again.
The flame sensor looks like a wire and it's in the flame usually it will get gas deposits on it, then it won't work.
You can clean this sensor with an extra fine piece of steel wool, but before you attempt to do this DISCONNECT ALL POWER TO THE FURNACE.
Is there a booster motor for the burner? I have seen these stick and make a furnace not turn on. The thermostat trips and you hear the furnace click on but nothing else happens. The booster is a small electric motor connected to a small duct. Take the booster motor loose and turn the fan by hand. Usually they will start working after you do this. Make sure furnace is shut off when you do this. Some booster motors have ports to oil them also.
The steps involved can vary slightly depending on your furnace model and pilot valve type, so if possible try and find the instructions inside the furnace door cover or in the instruction manual.
This is for a gas fired furnace, but applies to any gas-fueled appliance including water heater.
Two of the most common types of pilot valve body assemblies either have a red reset button and a gas valve or no reset button and a valve knob that can be depressed. But whichever type you've got, if you have an older model furnace with a standing pilot (flame is lit all the time) then this is the basic procedure.
Turn you thermostat to 80 degrees or to a setting that will demand heat. Make sure the thermostat is in "Heat" mode.
Go to the furnace and find the pilot valve. The pilot valve body is a box shaped device into which the main gas line will run and is located near the gas burners. It will usually have a gas **** or valve knob that reads "On, "Pilot" and "Off." Locate this gas **** or knob.
Turn the knob or gas **** to the "Off" position and wait about 3 minutes for any residual gas to clear away.
Find the pilot. It's located near the gas burner tube assembly in the furnace.
Get your match or lighter ready. Sometimes the pilot is hard to reach. If possible, try and use a long fireplace match when you light it. If you don't have a fireplace match then a butane BBQ grill lighter works well too. If you don't have that, then you can fasten a match to the end of a stick when you light the pilot
If you have a pilot with a red Reset button, turn the gas valve from "Off," to "Pilot."
If you have a pilot with no red button, turn the knob from "Off" to "Pilot."
Place the lit match or ignited lighter tip at the pilot and depress and hold the button or depress the knob as appropriate. Depress the button or knob for about 30 seconds. This maintains gas flow to the pilot until the thermocouple gets hot enough to open the main gas valve.
Once the pilot stays lit, slowly release the button or knob and turn the gas **** or knob from the "Pilot" position to the "On" position. This will ignite the burners and keep the flow of gas supplied as required for the burners as called for by the thermostat.
If the burners fail to ignite then it may be because the thermocouple did not get hot enough to open the gas valve. Wait a few minutes and then repeat the above procedure. This time hold the red reset button or depress the knob for about 45-60 seconds.
Once the main furnace burners ignite, adjust the thermostat to the desired setting.
If you've followed the previous steps on lighting the pilot and it still does not light after, or will not stay lit, then you probably have a problem with the thermocouple or an adjustment needs to be made to the pilot. You'll need a furnace service technician to replace or repair these parts.
You may find that the pilot lights, but it is an anemic looking flame. That's a different problem we'll look at in the next section.
If the pilot lights but the flame is a weak yellow flame, it will not get hot enough to heat the thermocouple to its set point allowing the gas valve to open.
A natural gas flame should be a bright blue with the tip of the flame having just a tinge of yellow. A propane flame should have a bluish green flame with a tinge of yellow at the tip. The flame should be strong enough to hit the thermocouple tip about 1/2 inch from the tip end. If the flame is weak or shaky looking, check to see that a breeze or draft is not blowing on it.
Adjusting the Flame There is usually a small screw on the pilot valve body that will adjust the flame. You may have to refer to the manufacturer's instructions to find the screw. Turn the screw as needed to adjust the flame throw.
Yellow Flame A yellow flame is caused by lack of air and incomplete combustion. It can be caused by a dirty pilot tube tip.
Split Flame This is caused by dirt in the pilot tube. Take a needle or small nail and gently clean the tube.
Flickering or Wavering Flame A flame that flickers is usually caused by a draft.
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Roscoe007 shouldnt speak unless he knows what he is talking about, as a heater installer i am telling you the ignitor needs to be replaced, the very fact that the ignitor does light for about 30 sec than goes out rules out any issue with the themostat, replace the ignitor!