Question about Heating & Cooling

1 Answer

Electric Furnace stopped running

My interior Carrier KFCEH3101C15 air handler/electric furnace stopped working yesterday. It is hooked-up to a newer (6 months old) 2.5 ton exterior heat pump. The furnace is a well-maintained 2006 unit that had been running very smoothly/quietly. I noticed the metal air filters were dirty so I blew them out and replaced them. I tried to reset the system by turning the thermostat below the air temperature reading then turning off the two circuit breakers on the unit for a minute, turning them back on, then setting the thermostat to about 5 degrees above the air temperature reading. The thermostat then read "Aux Heat" as if it was trying to raise the temp in the house but the air handler never kicked on. I turned the fan switch from auto to "ON" but the blower motor did not run. I took the access panel off and exposed the electrical components, blower motor and a-coil, and found the blower motor was humming lightly and felt warm to the touch, so that told me there was power to the unit. I can't see the heating coils to determine if they are warming, but I checked all 3 limit switches with an ohmmeter and they tested at 0.00 ohms (I removed them from the heat strip and tested them individually by pushing the "clicker" switch a dozen times or so and watching the ohms spike then drop off to zero)--I think this means the switches are good if releasing the clicker closes the switch and drops ohms to zero (please confirm)? There is no obvious reset button anywhere and no fuse panel on the furnace. There is just a 5amp fuse on the circuit board (looks like a fuse you would put into the panel of a car) which checked good for continuity. What else could keep it from running? How can I check that the heater coils are getting power (or will I be able to do that under the circumstances)? It's going to get very cold in the northern midwest here this week, starting tonight--I would very much appreciate your expertise if you could help me on this one. Thanks--and a very happy Veteran's Day to all vets, past and present.

Posted by on

  • Jim Glover
    Jim Glover Nov 14, 2014

    Check the continuity between the blue and yellow and you should have low resistance. The reading you are getting on the capacitor tells me you have a bad one. As long as the resistance is good on the motor; changing the capacitor most likely will get the motor running again. A motor humming and warm is a good sign that the capacitor has failed as long as the blower spins freely.

×

Ad

1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that got 5 achievements.

    Governor:

    An expert whose answer got voted for 20 times.

    New Friend:

    An expert that has 1 follower.

  • Expert
  • 107 Answers

You have one of two problems. Either the capacitor for the motor has failed or the motor has failed. I would turn off the power to the unit and see if you can locate the capacitor and remove it. An ac supply or electrical supply house can match up the capacitor. This is relatively inexpensive. Otherwise you will need a new motor.

Posted on Nov 12, 2014

Testimonial: "Thanks Jimg for hanging in there with me for some helpful dialogue over the last few days. You helped me narrow down the root cause to the capacitor and the blower motor and it turned out to be a bad capacitor. Your follow-up instructions also helped me to ensure safe testing and removal, and I'm very appreciative for your help. For anyone reading this comment, please be sure to read the entire post for specific details and safety considerations. Thanks and best wishes to all."

  • 4 more comments 
  • Dave Strasinger
    Dave Strasinger Nov 13, 2014

    Thank you, Jim. I found a site that recommended checking the integrity of the capacitor first http://www.hvacpartsoutlet.com/troublesh... The site suggested using a multimeter with an “MFD” setting. I only have a basic multimeter (ohms, DC amps, and voltage settings only) and I couldn’t find one with an MFD setting at Sears, Home Depot, or Harbor Freight—do you have any idea how I can test it with my basic multimeter? Also, assuming the capacitor is still holding a charge, how would I test (and possibly remove) it without shocking the shazam out of myself? Do you have a method for unloading the charge? It’s a standard run capacitor, if that helps. Lastly, if the capacitor is good, can you guide me through testing the blower motor? This thing is a multi-stage motor and has ten wires running into and out of it…not sure where to begin. Thanks again!

  • Jim Glover
    Jim Glover Nov 14, 2014

    Since you have that type of motor; you probally will not have a capacitor. And I never have used a standard multimeter to test capacitors because I wanted to know my microfarad reading. The old analog meters with the needle because you place the leads across the terminals and then watch the needle drop. If you do have a capacito; which at this point I doubt. After turning the power off use a screwdriver to "short across the terminals; this will ensure the capacitor discharges. An electrical or HVAC supply house can test it for you. It sounds like you may have a electronically commutated motor which means the motor will have to be replaced; according to the symptoms you are describing.

  • Dave Strasinger
    Dave Strasinger Nov 14, 2014

    Hi Jim, there is a standard run capacitor attached to the blower motor housing that looks like the one pictured in the link in my previous post. It has two terminals on top with four leads per terminal. I'll follow your instructions to discharge the capacitor to test it. I was able to pick-up a multimeter yesterday that can measure MFD/uf's, so I'll give that a shot this morning, following the capacitor troubleshooting instructions from the link in my previous comment. I'll let you know what happens next--thanks for hanging in there with me, I appreciate your time more than you can know.

  • Dave Strasinger
    Dave Strasinger Nov 14, 2014

    Update (11/14 11:00am): I bled down the capacitor as you suggested (thank you) and tested it with a multimeter capable of reading microfarads. The reading was 0.L (appears to be dead). Assuming I tested it correctly (following the instructions I referenced previously), according to the rating on the label, it should have read approximately "10" (+ or - 5%). See the attached pictures. I am going to start calling local electric supply houses in a few moments to look for a replacement (I'll ask them to bench-test mine while I'm there to back-up my findings) but I also want to let you know that I took a closer look at the blower motor and it has only seven wires coming from it. If you look at the picture, the black and red wires are capped-off...they are coming out of the motor but not connected to anything, The yellow wire is connected to the transformer and the blue wire goes to the main circuit board. The small yellow/green wire is a ground and the two loose brown wires went to the capacitor. Based on this, can you tell me how I can test the blower motor?



  • Dave Strasinger
    Dave Strasinger Nov 14, 2014

    FIXED! Glory to God. The root cause was a bad capacitor, which if you look in the above picture is actually bulging a little (an indication of failure), likely from a mix of overheating time and again and age. I installed a new capacitor this afternoon (10MDF/uf 440VAC, in-stock at Grainger for $10.83) and installed it. I flipped on the breakers and 30 seconds later the blower starting running. It has been running like a charm for four hours now and we've gone from a cold 26 degrees to a warm 72. Thank you, Jim, for helping me to narrow down the cause--you're a good man. A very Happy Thanksgiving and Merry Christmas to you!

  • Jim Glover
    Jim Glover Nov 15, 2014

    Not a problem. Now that you mention the bulging capacitor and yes I've seen that many times. Congratulations on your repair.

×

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Does it need propane to run the furnace or can it operate on electric alone. i have no owners manuel


Got here late...I am assuming this is for an RV. There are probably electric furnaces on some of the newer ones, however, an electric furnace would draw more power than most parks could handle, so the is answer is it probably needs to have propane. On your panel, or near your furnace, you will see a switch to tell the furnace to use propane or electric...if your furnace is capable of running on electricity.

Sep 30, 2015 | Cars & Trucks

1 Answer

Replace a kfceh3101c15 with a 20 kw. 15 kw just is not keeping up in this weather


The best answer would come from Carrier. Here is their contact info-

Feb 23, 2015 | Carrier Heating & Cooling

1 Answer

Carrier electric furnace (air handler) stopped running


The 5 amp fuse may be bad, they go quite often, and they are exactly the same as the car ones. Check the fuse with a meter. If its OK turn the unit on and check for voltage going to the blower fan. You should get a reading between at least one pair of wires. The unit should have a schematic on it somewhere, check it to see which wire pairs are used for the variable speeds of the fan.

Nov 08, 2014 | Heating & Cooling

1 Answer

Carrier electric furnace/air handler stopped running


Check fuses first! If yours is the model with a fuse box you will see a flap that pulls down to reveal a block of fuses, the blade fuse you described is part of it too! Are all fuses ok?

Nov 08, 2014 | Heating & Cooling

1 Answer

Carrier air handler/furnace won't turn on


from what your saying the motor is hot to touch if that is the case the motor is bad need to be replaced.

Nov 08, 2014 | Heating & Cooling

1 Answer

The line is frozen and the fan will not shut off. How do I turn the fan off?


Shut off the electric to your furnace.

the reason that the line is frozen is because of one two things:
First there is enough air passing over the A coil on your furnace.
Could be dirty filters - closed vents- furnace fan will not run/ stops and starts (bad motor).
Second the charge on your a/c unit is low.

John

Jun 24, 2014 | Carrier XHB123D X/Y Series Heat/Cool Air...

1 Answer

Electric furnace/air handler short cycles


check that the replaced thermostat is the same temp degree setting of the last one

Dec 16, 2013 | Goodman Heating & Cooling

1 Answer

Furnace switches to auxiliary heat while in cool


It's likely a bad tstat. Turn the power off to your air handler. Remove red , green, yellow and orange wires inside the tstat and wire nut them together. Not sure if your reversing valve energizes in heating or cooling but, turn the power back on. If the unit is heating turn the power off and remove just the orange wire and turn power back on. Let this run and see if it you are ONLY getting cool air ALL the time. If so you have a bad stat. If still getting heat possibly you have a bad control board in the air handler. Good Luck!!

Apr 15, 2017 | Honeywell Heating & Cooling

1 Answer

Thermostat issue with comfort zone II.


Is this an electric or gass furnace - Eather of these can can have this problem its most recomendable that you call a seviceman .
in the case of electric furnace you may requier a new heat sequencer. And in the case of gass you may requier a new relay.

Feb 18, 2009 | Carrier 38CKC060 Air Conditioner

Not finding what you are looking for?
Heating & Cooling Logo

Related Topics:

140 people viewed this question

Ask a Question

Usually answered in minutes!

Top Heating & Cooling Experts

paulcarew

Level 3 Expert

2515 Answers

Dan Webster
Dan Webster

Level 3 Expert

8220 Answers

Donni Steen

Level 3 Expert

659 Answers

Are you a Heating and Cooling Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...