Ducane Furnace One Cycle Then Doesnt Start Again Without Flipping the Breaker

Furnace or A/C Blower Fan Won't Finish
What to Check if the Blower Fan Keeps Running

• POST a QUESTION or Comment about diagnosing furnace fan operating problems

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Forced air heating or cooling air handler troubleshooting: blower fan won't shut off:

This article describes what to cheque if the furnace or forced air blower fan does not terminate when y'all expect it to do so.

These same diagnostics too assistance in ac blower assembly diagnosis when an A/C blower continues running. We explain what switches or controls may exist set improperly or what else, such as a shorted wire, can crusade continuous HVAC fan operation.

We also provide an ARTICLE Alphabetize for this topic, or yous can try the page top or bottom SEARCH BOX equally a quick fashion to find information you need.

What to Check if your Furnace Fan or Air Handler Blower Fan Runs Continuously

These diagnostic steps are for an air handler, blower, or furnace fan that just won't quit running.

Other heating system issues that can cause a furnace (or banality) to reject to stop are given

at HEAT WON'T Plough OFF.

First, confirm that the room thermostat is not calling for heating or cooling.

In the heating season, just set the thermostat(s) to the lowest setting and confirm that room temperature is higher up that point. In the cooling flavour do the opposite - prepare the thermostat to its highest setting and confirm that room temperature is beneath that point.

You lot have told the thermostat to plough off the HVAC equipment.

If the equipment was running give it three to four minutes to shut down.

Next: If the blower simply keeps running no matter what, there are two places to check switch settings before calling your heating or air-conditioning service company in response to a furnace fan or air conditioning fan that just keeps running without stopping:

1.CHECK the FAN-Motorcar setting - At the room thermostat: the FAN-Motorcar-OFF or FAN ON/OFF switch on the room thermostat should exist checked.

The fan command should be set to AUTO. Yous tin try turning the switch to OFF as well.

Details of checking the thermostat's FAN-Car-OFF or FAN-ON switch position when the furnace (or ac) fan won't stop running are

Those issues are explained

at THERMOSTAT WON'T TURN OFF.

2. Cheque for a Transmission - ON Switch - At the furnace or air conditioner air handler or blower unit: the fan limit switch may include a switch that manually keeps the fan running.

Nosotros discuss this switch right here. If you don't know where to find the limit control switch on your furnace or air handler,

see FAN LIMIT SWITCH.

Some models of Fan Limit Controls such as the Honeywell L4046B229& Universal Fan and Limit Controler, in particular the Honeywell L4064B,Westward, and R models accept a manual fan switch that overrides the fan command to keep the fan running continuously. The white knob and white arrow in our photo point to this manual fan switch.

Take a look at the fan limit control switch. Before pulling the cover off of the switch, just come across if the switch includes a control such as the white push button-pull switch like the white device shown at the lower left in our photo.

Depending on the position of this switch (pushed-in or pulled out) the fan may be on manual override - causing the fan motor to run continuously.

Cheque the printing on the switch face to run across if you should button the switch in or pull it out to leave the blower on "Auto". ("Man" or "Manual" would exist forcing the fan to run.)

Which way to set the manual furnace or air conditioner blower fan switch:

Usually: "Button-in" position on this (Honeywell) fan limit switch is for continuous fan operation and "Pull out" position is for automatic fan functioning.

There are some reasons (explained

at BLOWER FAN CONTINUOUS Performance)

to leave the blower fan on continuously for long periods, such equally to use an air filtering system to meliorate indoor air quality.

And in some buildings we may run the blower continuously for more than even or better conditioned (heated or cooled) air distribution.

What Else to Check if the Blower or Furnace Fan Won't Stop

On the off run a risk that someone has inadvertently mis-connected or shorted fan control wires at the fan limit switch, also check

out FAN LIMIT SWITCH INSTALLATION & WIRING.

On the run a risk that there is a shorted thermostat wire, a problem that can also crusade the A/C or warm air furnace fan to run continuously

see THERMOSTAT WON'T TURN OFF.

Details nigh the transmission FAN ON or FAN AUTO ON switch right at the furnace or air handler at the transmission

at BLOWER FAN CONTINUOUS Performance.

This article serial answers virtually questions nearly fundamental heating system troubleshooting, inspection, diagnosis, and repairs.

We depict how to inspect, troubleshoot and repair heating and air conditioning systems to inform abode owners, buyers, and home inspectors of common heating system defects.

Contact us to suggest text changes and additions and, if you lot wish, to receive online listing and credit for that contribution.

Reader Question: Furnace fan keeps running with no heat coming from the furnace

2015/x/22 Anonymous said:

My fan keeps running with no heat on furnace. What can I do?

Reply: half dozen steps to getting estrus on when the fan runs but the furnace does non

If the furnace does not even try to run, that is if it never fifty-fifty starts, so follow these steps:

1. Bank check the thermostat settings to exist sure that you are calling for heat (fix-temperature is above room temperature).

   See THERMOSTATS, HEATING / COOLING - dwelling house

2. Check that the thermostat FAN switch is set to Auto not to ON.

   Run across THERMOSTAT SWITCHES, EXTERNAL

3. Check that the manual FAN ON switch at the fan limit switch in the furnace or air handler is not in manual ON position.

   See FAN LIMIT SWITCH for details.

4. Check the furnace primary controller to see if the "reset" button on the control (or on the burner motor) has popped out - you can endeavor pressing the switch in Once but don't proceed pressing it as doing then is unsafe.

   For oil fired furnaces see RESET SWITCH - Heat Control

   or see RESET SWITCH, CAD Cell RELAY

   or on older furnaces come across STACK RELAY SWITCH

   For electric motor reset switches that are present on some (not all) oil burners

   see ELECTRIC MOTOR OVERLOAD RESET SWITCH

   For gas fired furnaces

   run across FLUE GAS SPILL SWITCH TRIPPING & RESET; other defects such as a bad thermocouple tin proceed the gas burner from igniting or burning.
   
   For gas burner thermocouple problems

   see THERMOCOUPLE REPAIR / REPLACEMENT

5. Bank check for voltage at the oil burner primary command. This is a simple exam to see that power is really being delivered to the oil burner control. You can use a neon tester, a VOM, DMM, or a voltage detector stick.

   Watch out: if you are not expert in safety employ of electrical test tools you could be electrocuted - killed. Call an expert.

   Come across VOLTS MEASUREMENT METHODS

6. Check for a bad chief control: If there is voltage to the principal control, no reset buttons are popped, and the thermostat is calling for heat (check that right at the primary command thermostat wires) then I doubtable a bad primary control unit itself.

   At that signal your heating service tech will perform her own tests and so if needed repair wiring or supersede the furnace control.

   Oil heat: see CAD CELL RELAY SWITCH
   or
   Gas heat: see the gas furnace controls cited above at step iv.

If the furnace tries to beginning but cannot keep running and so there is a different trouble such as no fuel or an unsafe status.

See DIAGNOSE & Set up HEATING Problems-FURNACE - abode

A complete list of oil and gas fired furnace controls is

Reader Q&A - too see the FAQs series linked-to below

Nathan

Good going on those diagnostic steps.

You're right that a furnace that uses "snap disc" controllers to manage the fan won't have a Honewyell dial-blazon fan limit control; only information technology's of course all the same performing those functions: fan ON OFF and High limit settings are controlled by those snap-disc controls (whose wiring you may want to follow & check out)

With the thermostat wires completely disconnected at the air handler end, and when the fan won't stop, we dominion out an issue with shorted TT wires likewise as a bad thermostat or thermostat setting.

Of course "won't cease" bears some description: information technology is proper for the fan to continue running for a minute or so later a call for rut, to extract the remaining oestrus from the heat exchanger and thus avoid damaging it.

If you are admittedly sure that there is no FAN ON control anywhere on the furnace, and it's disconnected from the thermostat wires at the furnace end then in that location'due south non much left: I'd suspect a bad snap disc, (I hear that you tested it), a shorted wire in the air handler, or a bad relay in the air handler.

Give thanks you. I take looked through your commodity extensively and tested at each place that is applicative to my arrangement. Though I very well could have missed things as I get lost in the different types of systems.
It is an electric heating system with a rut pump and furnace.

1. Thermostat fan set up to auto. Notwithstanding runs all the time. Smart thermostat indicates that fan is off. Thermostat still calls for the fan when the furnace kicks on but when the furnace turns off and the fan is no longer called for at the thermostat information technology still runs.

2. It doesn't seem as though at that place is a shorted wire as when I disconnect the thermostat from the furnace by disconnecting it's wires at the Air Handler, the fan still runs.

3. There is no fan limit switch that I am aware of. It is a Trane and the furnace is BAY96X141502.

four. This system has a snap disk blazon limit switch. Only I take checked information technology with a multimeter and it appears to be working correctly. Also the furnace is running as it should, just with constant bravado and so if i understand correctly the limit switch would also be keeping the furnace from running normally.

Let me know if i'm missing checking something and I'll check it out.

Nathan

Let's start I asking yous to review the causes of blower fan non stopping that are given in the article to a higher place on this page because that's more complete than if I attempt to make that up again in an off-the-gage reply.

Please take a look and let me know what you think and let me know what questions remain.

How-do-you-do looking for some technical help with our HVAC system. I only replaced the blower motor in our furnace and information technology is running constantly since the modify. I've disconnected it from the thermostat to isolate the problem and it yet fires up as before long as the power comes on and stays that fashion with or without the furnace engaged.

The furnace itself still turns on and off as normal then I don't remember it'south the furnace limit controller reading overheat or going bad. I suspect it could exist a bad relay.

The thing that really confuses me is that every morning when I wake up information technology tends to be off and stays that way until triggered either by the thermostat, the fresh air commutation or fifty-fifty me cut the power and turning information technology dorsum on gets information technology going again. Then information technology stays running until the side by side morn once more.

Keith

let's first by stepping through the Diagnostics given on the folio higher up. Let me know what discover or what questions remain.

my furnace will not close off i have to use the breaker to shut it off

i have a colman electric furnace that wont shut off

give thanks you for that it, too. Your paragraph yes I hold and we discussed in this article serial The observation that information technology's absolutely important for the blower fan to continue running for at least a brief fourth dimension after the thermostat stops calling for heat. That's to excerpt the remaining heat out of a heat exchanger and thereby to avoid cracking the heat exchanger from high temperatures which in turn could brand the furnace Dangerous and risk carbon monoxide poisoning.

So to exist clear we should distinguish between the fan continuing to run for a brief interval typically 30 seconds or a minute afterwards the call for estrus of satisfied as distinct from the fan that just runs continuously.

If the fan runs continuously with never shutting off that's the situation discussed on this page and is not that he'southward purging cycle that you institute in the instructions and that we also discussed in this article series

Thanks.
I looked all through the duct work and there is defintely no controller in there. The stat is set at auto and it is a fairly new stat.
The manufactures information says,

"Time delay for blower activation: 60 seconds (std.)

130 deg. F Aquastat (w/optional aquastat).

Then i think that 60 sec delay is just built into the board

I don't encounter any options or markings for time delay nor any DIP switches.
Anyway I can test information technology?

thanks for your help

Institute a bit more info looking through the information sheets,

Units without Factory Installed Aquastats or Deactivated Aquastats- A time delay of 60 seconds follows before the excursion between R and G are complete activating the indoor blower motor. The Air Handler fan volition plow off 30 seconds later on the Thermostat stops calling for heating.

Ovsa

There is ordinarily a fan limit command in the air handler that turns the fan on or off depending on air temperature sensed in the plenum just above the heater's heat exchanger.

If the fan won't stop on your unit look for one of the controls described above on this folio and that can be used to manually turn the fan on for continuous operation. Ane of those is on the fan limit control, some other is often on your room thermostat, and on occasion in that location may be a fan control correct on the printed circuit board in the air handler.

Look furhter for a control lath failure: if your air handler does not use a separate timer-containing fan limit command the fourth dimension delay in fan shut-off may exist controlled by dip switches on a control board or by a hard-wired timer.

If you don't accept the transmission for your unit of measurement see

ADP ADVANCED Distributor PROUCTS heating & cooling systems

Or this may be the IO Transmission for your unit:

ADP B-Series Multi-Position & Hydronic Air Handlers IO Manual [PDF] (2017) Electric or Hot Water Heat, with available Variable-Speed High Efficiency ECM Motor

I have a ADP air handler with a hot h2o heating gyre and a refrigerant coil. My thermostat controls the HW recirc pump.
in heating mode afterwards the recirc pump shuts off the fan keeps running, forever.

I do not see an aquastat or fan limit switch in the housing anywhere.
my question is what controls the fan on/off? Is information technology programmed right into the circuit lath or am i missing something?
thanks

Ed

Essentially, yep. IF your limit switch has no Homo-ON switch (found as a white button-pull knob or every bit a pocket-size metal slide left-correct lever) so yep that control is in automated mode.

However some thermostats also include a FAN ON / Auto / switch that can too command the fan.

If your fan NEVER turns off regardless of the thermostat setting then I suspect either one of the issues listed to a higher place on this folio

OR

ane of the situations described at FAN WONT STOP - THERMOSTAT SWITCH

If our honeywell fan limit switch does not have the auto/manual button/pull button for the fan, then is it prophylactic to presume that it is always ready for auto? Our limit switch does not have the hole for the button in the comprehend, merely when opened, it looks like the image above except in that location is no white button.

Maybe it broke off? (we but bought the business firm and moved in then don't know).

I read another comment from someone who said that not all models have the button, but our'due south keeps running well afterward the temperature is reached. Whatsoever ideas on how to make certain the fan limit switch is fix to auto?

Hi! My Honeywell digital thermostat is assail cooling currently and the fan is set on auto. Everything seems to be working fine, except every morning time the blower fan comes on for a long time (an hour or more) even though the thermostat shows no activeness (cooling ihas non come on)

The inside temp is already at set point and drops to a couple degrees beneath the set point within a few minutes of the fan coming on and stays there the whole time the fan is running. This does non seem to happen at other times of solar day. The thermostat seems to exist working the manner information technology should.

Well, it turned out to be something verrrrrrrrry simple, just somewhat elusive!

I checked all wiring from tstat to airhandler, and from airhandler to compressor. All lines were continuous, with no shorts to any other lines.

The compressor continued to run intermittently, with no icing seen on coils. The vent temps were65-66 degrees. After everything I tried (new airhandler fan delay/relay board, NOS tstat) got same intermittent results, I figured the compressor was shutting down for some type of overheat situation.

The reality...was different....*facepalm*

Contractor came out, gauged compressor and looked at boards on compressor. He and so checked the airhandler, and the condensate float switch (hither it comes!).

He saw some h2o in the switch cup, and said "you've got a clogged drainline. That'southward what'southward shutting down the compressor." He blew out the line, and systems been running like a meridian since and then.

The clog must have been *partial*, with wearisome drainage. Betwixt cycles, the line would drain plenty to let float switch drib, and enable the compressor to run.

The compressor would run, cool the coils, and condensate would brainstorm accumulating-- until it began to back up in the slow drain, and lift the float switch--and shut down the compressor. I did actually peek in the bladder switch loving cup several times, and never saw anything. I must have been looking afterwards it had drained downward.

Spiro

Let's showtime with the Diagnostics above on this page every bit that volition be a more complete process than if I endeavor to make information technology upwards once again typing in an off-the-cuff reply here. Please look through those steps and permit me know what yous find.

I take a Payne all in ane blower condenser unit. My blower is staying on all the time.

Right.

The simplest and nigh straightforward exam is to disconnect a thermostat wires at both ends and so working from each stop test for any continuity betwixt whatever pair of them.

Let me know what you find

thank you, I shall ohm out the control wires from thermostate mount plate, and check for shorts. Assumption: the W, Y and G should take no continuity
to C (ground), or to each other--correct?

I plant a discussion in another forum with same symptoms (intermittent failure of airhandler to stop blowing afterward reaching setpoint temp), where poster plant the 1000 line was left 'floating' (as opposed to being grounded) at setpoint shutdown. He conjectured about putting a pull-downwardly resistor across Thou and C, to drain any stray/leftover voltage at setpoint shutdown. He mentioned a 5K.

I just installed a 100K across G and C. Should only load 24VAC transformer with an boosted 24mA.

A cooling bicycle but completed--system cooled to setpoint, thermostat clicked, and near a minute afterward, airhandler stopped blowing---good! Fingers crossed that this solved it!

I got that, Steve, but I'm not clear on whether or not yous found that by disconnecting the TT right at the air handler was done at a time when the AHU was running when you call back information technology should non.

Taking that step non only rules out a bad thermostat simply also mistakes in thermostat wiring and likewise the more-subtle problem of thermostat wires that are shorted together somewhere enroute.

I've already asunder the thermostat, and replaced it with a brand new one...along with replacing the blower time delay relay board.

Have you lot tried disconnecting the thermostat right at the air handler? That tin dominion the thermostat out.

I've got the same problem, as posted On 2020-03-04 past Forrest.

My Amana/Goodman ARUF3714C airhandler keeps blowing, even after thermostat reaches set-point; compressor shuts downward, but airhandler keeps blowing. The problem is *intermittent*--sometimes airhandler shuts off, sometimes it merely runs and runs (not the 65-2nd efficiency delay).

Figured it was the blower delay relay lath; replaced information technology and all seemed ok for a few days. It started up once more today. I chosen Goodman and a tech suggested the thermostat might be defective. I had a new-in-box thermostat on paw, and wired it in.

It'south doing aforementioned thing--seemingly random failure of airhandler to shut downward, after reaching prepare-point temp.

I'm wondering nearly either the control wiring, or the 24 volt transformer. We had a power outage a few days before this problem started, and wonder if the transformer might have been zapped, and isn't putting out 24 VDC.

The other possibility is wiring--if there's some random short or open up, responding to equipment vibration or...?

How to check the command wiring? Is "C"/blue the common basis? What wires should be 'shorted' to each other, or to footing, during unlike operating states?

Bill

Your service tech might cheque for a bad control board or ice blocking on the cooling coil

I have a 15 sheer unit that blows strong and so weak, but continues to go up and down when activated at Temp setting. I hateful information technology blows loud then soft and then loud simply maintains temp.
Whats happening tin someone tell me what can I do ?

If the blower previously would run in high speed then I suspect a failed relay or control board.

Why won't the blower plough on high on my Goodman heat pump and Goodman furnace while in the cooling fashion

Take you checked for shorted wires anywhere in the control circuit?

blower motor on air conditioner volition not close down. I put in a new control board,that didn't work.put in a new contactor switch.that worked for 8 day'southward then stopped working.put in another contactor switch .the same. fan motor all the same runs constantly.

Tab

Your heating service tech may find a bad switch or control or fifty-fifty a thermostat set wrong or shorted thermostat wires.
She might check the diagnostics higher up on this page first.

My furnace fan in my firm won't turn off when my unit of measurement is off

Jamie

Perhaps there is a defective fan limit command or fan relay control switch.

Sometimes my blower fan won't close off for a while. Information technology will work for half the mean solar day and and so the other half of the solar day it volition not shut off.If I flip the billow off and right back on the fans stays off until the next cycle.

First let'south place the exact brand and model of heater and then look at the manual to see what settings are bachelor.

On most equipment there's actually a user operable switch that will turn the fan to run continuously. But on some information technology might exist a dip switch or jumper.

The other place to look of grade is at the thermostat. You can rule out the thermostat by disconnecting the thermostat wires entirely at the heater. If the fan keeps running then it's not a thermostat setting.

Thank you lot for getting dorsum to me. You mean you retrieve it's the ECM problem (bad or set that way) as well?

What do I demand to practise, if I don't want the fan constant bravado?

I agree with you that typically in that location's either a switch set somewhere or a shorted wire or bad command

Cheers for all the very very helpful information found on this website! I am a new homeowner and I found the blower fan (Genteq Endura ECM FM19, i/2 hp, 230VAC) installed has been running constantly. This is what I have gathered and then far:

1. if I disconnect 5-pivot low voltage signaling on the ECM, the fan still runs.

2. I checked voltage on the 4-pin power supply to the ECM, they are all right (C-0V, Fifty-115V, Thousand-0V, N-115V).

three. snap-disc thermo switch checked.

4. heat sequencer checked (I have a heat pump and electric rut).

5. fan relay is quite hard to reach, merely when I call fan-on, the relay clicks and the fan blows a little bit stronger.

6. interior of ECM looks corking, no dust, no rust, no busted capacitor, perfect rubbery seal.

I suspect the ECM module is programed to run the motor non-stop, by the builder or previous owner? Program # 604253-05. Or what else could exist the trouble hither? Thanks once again!

Regards,
Nemo

This sounds as if the FAN ON switch is set to ON at the thermostat or on the fan limit controller inside the furnace air handler

AND

that your furnace is not working - that is the burner won't run. Depending on the fuel (oil, gas, electric) you lot'll find different diagnostic routines in the Commodity INDEX given in the Keep Reading department of this page

Blower fan continuously running while rut off switches on heat and on auto no fire in the box fan still runs

Question:

2019/11/04 Misty Lawhon

I think my air off and the fan off but my furnace keeps lighting upwards. I'yard worried it with take hold of burn.

Respond:

Misty

I tin't tell what's happening with your furnace from your brief text: is the thermostat calling for heat?

Scout out: In any event if you have the slightest worry that the heater is dangerous and then

I promise yous simply shut down the system so called for repair;

Question:

2019/10/18 Henri Nseke

Can blower running constantly

Question:

2019/08/fifteen Rick asked

Why does the air conditioning blow thru furnace

Reply:

It's using the indoor furnace fan to blow cool air through the aforementioned duct system used for warm air heating.

...

Keep reading at FAN WONT Finish - THERMOSTAT SWITCH, or select a topic from the closely-related manufactures below, or see the complete ARTICLE INDEX.

Or see FURNACE FAN WONT STOP FAQs - questions & answers about why the furnace blower fan won't terminate running

Or encounter these

Recommended Manufactures

• AIR HANDLER / BLOWER UNITS - home
• BLOWER FAN Functioning & TESTING
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• FAN MOTOR First CAPACITORS
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• FAN Free energy Alphabetize FEI
• FAN LIMIT SWITCH
• FAN LIMIT Command SETTINGS
• FAN LIMIT SWITCH INSTALLATION & WIRING
• FAN LIMIT SWITCH TROUBLESHOOTING
• FAN RUNS ONLY ON FAN-ON / MAN
• FAN WONT STOP - LIMIT SWITCH
• FAN WONT STOP - THERMOSTAT SWITCH
• FURNACE BLOWS Cold AIR
• FURNACE FAN CYCLES Subsequently Oestrus
• FURNACE FAN CYCLES DURING Estrus
• FURNACE FAN STOPS EARLY
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• FAN WONT STOP - THERMOSTAT SWITCH
• UNDERSIZED RETURN DUCTS - not enough return air

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FURNACE FAN WONT STOP at AuditApedia.com - online encyclopedia of building & ecology inspection, testing, diagnosis, repair, & trouble prevention advice.

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INDEX to RELATED Manufactures: Commodity Alphabetize to HEATING FURNACES

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