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Jump it,if it allows you and check for continuity and check for 24v.


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I consult to most all warm air furnace OEMs. The best answer is it lights the first time, every time. There are of course things that can prevent that...low gas pressure switches, low air pressure switches, limits not being made (door switch, air switch, fan speed proving, condensate switches, etc.). That being said...EVERYTHING good...GAS supply...AIR ...


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I would first fully inspect the exhaust for obstructions. It is quite possible that in the process of combustion, pressure is building inside the heat exchanger, and then having difficulty moving through the appliance to eventually exhaust. The inducer is designed to help overcome this. Basically, what happens is that the combustion pressure overcomes the ...


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These are all great suggestions to look at, but I had the same problem on my goodman furnace and the service people came and kept replacing the the pressure switch ... and the problem you described continued... Finally I bought a new controller board for the unit for about $60 (ebay as I recall) and installed it myself. The unit has worked perfectly for ...


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Does this furnace have a condensate drain? I had a similar problem with a high-efficiency gas furnace, and the problem turned out to be a gummed up condensate trap. I disconnected the hose from the front end of the trap, and about a quart of water poured out of the drain line. I removed the trap, flushed it with water for about 5 minutes, reconnected, and ...


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Sounds like the capacitor is dead/dying. If you have a capacitor tester, or a multimeter with a capacitor test feature, you can test the capacitor. There should be a micro farad rating on the capacitor (e,g, 10µF), and a variance percentage. When you test the capacitor, it should be withing the variance percentage. If it's not, then it's bad. For example a ...


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This is not really an answer, since I don't think this can be answered without being on site. Rather, I'm going to explain a bit about how the system works, and offer a few ideas as to what the problem could be. To start, you'll want to understand how air moves through the system. You'll want to know the difference between conditioned air, and combustion ...


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My furnace would ignite the pilot and energize the induction motor but the main burner valve would not open. At first I suspected a bad coil on the vale selonoid but continuity check indicated it was good. Then traced around with my meter and got to the pressure switch. It was not switching when the induction fan ran. I removed the tube from the furnace and ...


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If the blower is continuously blowing, then one of the limit switches is open. It may not be the high limit, but it's certainly one of them. Without knowing more about the unit (model number, photo of the schematic, etc.), it's difficult to offer much more assistance.


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Cut the gas back some by slightly closing the gas valve (the one on the pipe, not in the unit), however be prepared to have to reset the furnace occasionally if your local gas pressure drops intermittently. Watch the flames as you do it. Just, "take the edge off". This will cost you more in electricity, as it'll run longer to come up to temp, but it will ...


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Having an oversized furnace compared to the needs of the conditioned space should not cause furnace limit problems unless the duct system is too small. If the furnace was installed by the same people as the duct system they should be allowed to address the problem. There are limits to how many outlets can be closed without causing this problem.


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C is the unswitched line from the transformer. 2 wires come from the transformer, look for the one that connects direcctly to one side of every load and find its terminal. The switched line is the other line from the transformer and goes to all the controls. Most systems use C. Trane/ American Std use B.


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In thermostat wiring, C stands for Common. Look for a terminal labeled Com, which is another abbreviation for common. I did not look up your thermostat, however it is likely that it needs the common wire to work properly. Many thermostats don't really need a common wire but it is almost always recommended to have one especially with these "smarter" ...


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I had a similar problem in which the furnace would start its pre-purge cycle, and then shut off. The root cause was a broken solder joint on the controller circuit board, which I was able to see with strong reading glasses, and later repair by myself. Try wiggling the low voltage electrical cables when your furnace acts up. If you find an intermittent ...


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btw i have the same issue on my HE home furnace. and just by chance, the billing department manager at the furnace company i use has the same problem. i did see an online article which mentioned some solutions. NOTE that exhaust pipe condensate drainage is the first thing i noticed appropriate to my problem. '....http://bassetheating.com If you experience ...


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I'd add this as a comment on KyleL's response, but I don't have the rep to do so yet. You should check to see if your humidifier is fed with hot or cold water. A hot water feed will have an increased rate of evaporation over a cold water feed. If your humidifier is connected to a cold water feed, switching it to hot may fix your problem.


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I ran the following tests with an ambient temperature of approximately 70 degrees F. I measured the (hot) water flowing into the humidifier and the water flowing out of the drain to calculate the % evaporation in each case (there is a reasonable margin of error). Furnace running in low stage. Approximate air temperature coming from register is 120 ...


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You could use the EAC-1 terminal to power a step-down transformer. This is common with furnaces that energize the HUM terminal to line voltage. Check the humidifier manufacturer, they should have a properly sized transformer to fit this exact need. They should also have a wiring diagram for this type of setup, in the installation instructions. ...


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So the problem ended up being the contactor on the outside unit. How I went about troubleshooting the problem was to disconnect the outside from high voltage power. Then I turned on the thermostat and allowed it to cycle a few times over the course of 2 days. The fan would come on as expected and the fuse never blew. I ordered a new contactor and ...


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It sounds like you fill valve is not properly set, or has failed. Do not run the furnace until you are sure the system (boiler shell, circulating pipes, and radiators) are completely filled with water. If the water level in the boiler gets too low the system could be damaged. Boilers usually have a fuse plug that limits the damage if the water level fails, ...


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This picture shows a typical gas-fired, hot water furnace system: The black thing in the center is the recirculator pump. When the furnace runs that recirculator is supposed to run. If you touch it or put your ear to it, you should detect it running. If it is making no noise, or is buzzing, then it needs to be replaced.


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That's what it's supposed to do. It heats until a "high" cut-out temp, and rests until a "low" cut-in temp. If it's colder outside, that will chill down your house much faster, it will hit the "cut-in" threshold much sooner, and cycle more often. So if it started doing this during the cold snap, that's why. If the heater is working at its limits due to ...


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I assume you are dealing with a gravity wall furnace, now made by Williams and Empire, and commonly found in California. They require no AC power. They use a thermocouple on the pilot light to power (via the thermostat) a millivolt gas solenoid. They sell special thermostats for this application. A "common" thermostat may or may not work, depending on its ...


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Your line of thinking is correct, in that a thermostat is simply a switch that connects two (or more) conductors together. If the thermostat is wired following common patterns, then connecting the red and white wires together should tell the furnace to try and fire up. If the unit works with the power off, then the control circuitry is likely powered by a ...


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If this problem just started (the furance hasn't always operated like this), then it's likely an open high limit switch. If it's a manually resettable limit, you can try resetting it yourself. If it's an automatic reset device, you'll probably have to replace it.


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It could be that your control is set to "Auto" instead of "Heat". Try changing the switch to "Heat" mode, adjust the thermostat set-point to slightly higher than the current room temperature & wait a minute or so for the furnace to turn on. After the set-point is reached, the fan should run a bit longer (less than 2 minutes) to blow the remaining ...


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After cleaning the flame sensor, checking ground wire, checking exhaust for cracks or blockage and the board connection which did not fix it. We found that the hanger on the exhaust pipe was hung poorly and causing exhaust pipe to droop down which made it hold condensation that ran back into unit which shut the furnace down. Fixed hanger to make exhaust ...


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After cleaning the flame sensor, checking ground wire, checking exhaust for cracks or blockage and the board connection. We found that the hanger on the exhaust pipe was hung poorly and causing pipe to droop down which made it hold condensation that ran back into unit which shut the furnace down.


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If partially closing a single supply vent caused your high limit to trip you probably have an restriction problem. I would recommend investigating a bypass damper with a return and supply temp. sensor. These devices are typically just a part of a whole house zoning system, but can be used to easily resolve supply air restrictions in situations where ...


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My Trane (5 yr old) has different possible blower settings for the heat and non-heat periods. My house was getting chilly in spots. So, I turned the fan up during the periods when the thermostat was not calling for heat. That circulates the air and has made the house a more even temperature. Meanwhile, the blower setting when the furnace is on has been ...


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You can't. I have the same problem. My house has a 125,000 BTU furnace for a 25,000 BTU heat load. My solution? I set the thermostat at 69 and turn it on manually when the temperature falls below 65 or so. This ensures that the furnace runs for a nice long time when it's on, and then stays off the rest of the time. But you don't really even need to do this ...


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I had same issue with the pressure switch randomly shutting-off. I couldn't get it to fire back up until I would smack it. After looking up the four flash code and reading this blog I located the wiring of the pressure switch and found it was loose. After re-securing the wire it functioned properly.


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You can just order a new filter if that makes you feel better. There is nothing wrong with replacing it. However most of the permanent ones can be washed in the dishwasher. I would look at the manufacturers guide and just clean it - as if something isn't broke why fix it. I have found getting replacements can be off by a little and cause issues. But you ...


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There is a thermocouple, the thing that is glowing red in the pilot light that tells the furnace the pilot lit. If that is bad it will continue to try to light the pilot. They are not real expensive but that would be the first thing to replace.



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