How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask M Oglesby Your Own Question

M Oglesby
M Oglesby, HVAC Technician
Category: HVAC
Satisfied Customers: 2038
Experience:  Universally Certified HVACR Technician
27079509
Type Your HVAC Question Here...
M Oglesby is online now
A new question is answered every 9 seconds

I have a LEnnox pulse 21 G2103-60-1 that wont start the heat

Customer Question

I have a LEnnox pulse 21 G2103-60-1 that wont start the heat cycle. the old thermostat clicked (I replaced the thermostat as a troubleshoot step) but the furnce wont kick on. the fan comes on, I was thinking a dirty ignitor switch - thoughts? how easy for DIY?
Submitted: 2 years ago.
Category: HVAC
Expert:  M Oglesby replied 2 years ago.

M Oglesby :

Remove the thermostat cover. You should see a R terminal W terminal Y terminal W terminal

M Oglesby :

Remove the wires from the R and W terminal and twist them together.

M Oglesby :

Go to the furnace and observe the ignition start up process. The inducer fan motor should come on first.

M Oglesby :

Let me know if it comes on or not.

Customer:

Thanks, XXXXX XXXXX Rh and W were not previously tied together, why would this happen?

M Oglesby :

They should not be tied together.

M Oglesby :

This is a troubleshooting method to bypass the thermostat.

Customer:

oh, okay, I will turn off breaker, then try this, BRB

M Oglesby :

ok

Customer:

hello

Customer:

I did observe the furnace "click on" to deliver heat, but I noticed a low hum sound.

M Oglesby :

It sounds like you inducer fan motor is not coming on.

Customer:

ok

M Oglesby :

Use a voltmeter to see if the inducer fan motor is receiving 120 volts.

Customer:

what do i do then?

Customer:

how do we detemine if that is the issue?

M Oglesby :

If it is, and the inducer fan motor is not coming on, then the motor is bad.

Customer:

hmm that sucks. is there another troubleshooting step we can do to focus on the issue before we resolve that is it?

M Oglesby :

No.

M Oglesby :

That is it.

M Oglesby :

Then inducer fan motor must come on first.

M Oglesby :

If it does not come on, then nothing is going to work.

Customer:

what does a replacement usually run? is it a DIY thing?

M Oglesby :

Yes it is a do it yourself thing. They usually run about $150

Customer:

dang.

Customer:

just go to Home Depot?

Customer:

how do I know the model, etc.?

M Oglesby :

But first you have to use the voltmeter to see if it is receiving 120 volts. If it is, then the motor is bad. If it is not, then the control board is bad. You cannot get one from Home Depot.

M Oglesby :

You will have to get the model number and serial number of the furnace.

Customer:

ok, thanks.

M Oglesby :

You are welcome

Customer:

so find someone with a voltmeter, check to see

Customer:

if what is receiveing 120v? what do we hook it up to?

M Oglesby :

Please hit ACCEPT if you are satisfied with this service. Thanks!

Customer:

well hang on, please

M Oglesby :

There are two wires hooked to the inducer fan motor.

M Oglesby :

A black and white wires

M Oglesby :

Remove the wires from the inducer fan motor and hook the meter leads to these two wires

Customer:

ok, so if that is NOT getting 120v we need a new board, if it is, then a new motor?

M Oglesby :

That is correct.

Customer:

okay, thanks, XXXXX XXXXX give it a go.

M Oglesby, HVAC Technician
Category: HVAC
Satisfied Customers: 2038
Experience: Universally Certified HVACR Technician
M Oglesby and other HVAC Specialists are ready to help you
Customer: replied 2 years ago.

Hello

 

I do not see any white and black wires on the furnace unit. I have attached an image to show you what the unit looks like. Any further assistance is appreciated.

Attachments are only available to registered users.

Register Here

Attachments are only available to registered users.

Register Here

Attachments are only available to registered users.

Register Here
View Full Image

Attachments are only available to registered users.

Register Here

Expert:  M Oglesby replied 2 years ago.
Can you send me a picture of the lower portion of the furnace?
Customer: replied 2 years ago.
I did not even realize that bottom panel comes off! Attached. Looks like there is a brown wire and a brown and white wire.

Attachments are only available to registered users.

Register Here

Attachments are only available to registered users.

Register Here

Attachments are only available to registered users.

Register Here
View Full Image

Attachments are only available to registered users.

Register Here
Expert:  M Oglesby replied 2 years ago.
that is not the blower you need to be checking. The one at the bottom is the blower motor. You need to check the inducer fan motor or exhaust fan motor. It has a rubber hose attached to it and connects to a round pressure switch. The wires may not be black and white, but is only has two wires attached to it. Check them to see if they are receiving voltage. I cannot see the inducer fan motor on your photos.
Customer: replied 2 years ago.
Thanks, what about the silver thing in the upper left corver of the first pic?
Expert:  M Oglesby replied 2 years ago.
That silver thing is the pressure switch. Is the green light flashing in a pattern? Such as 1 flash pause, 2 flash pause, etc...?
Customer: replied 2 years ago.

HI, thank you!

 

No, the LED light is solid green in the box just below it.

Expert:  M Oglesby replied 2 years ago.
Do you have the R and W wires twisted together at the thermostat?
Customer: replied 2 years ago.
I do
Expert:  M Oglesby replied 2 years ago.
The light should be flashing. This is a indication of control board failure. I advise you to have a tech come out and verify then repair.
Customer: replied 2 years ago.
Will do, thanks.
Expert:  M Oglesby replied 2 years ago.
no problem
Expert:  Billy replied 2 years ago.
Hello,the lit light on that control shows normal operation. The issue is likely inducer related. If the control is solid, verify if fan is running by feeling for air at exhaust. If it is not check voltage to inducer..also check limits as they will activate lockout also. There is troubleshooting in the back of this manualhttp://www.cozyparts.com/Lennox-Parts/forum/Lennox_service_manual/Furnaces/G21_GSR21_10-01-2001.pdf
Customer: replied 2 years ago.

Thanks Billy

 

When I turn on the fan, there is air blowing through the floor vents. I would like to check the inducer, but I cannot find it! Ha! I will check the manual for the inducer and "limits"

Expert:  Billy replied 2 years ago.

The manual will help you...the plastic pipes carry the exhaust fan air..so they will lead to it.

 

also look at component placement in manual.

 

 

Customer: replied 2 years ago.
Thanks, what about the reset button on the blower - is that of any value?
Customer: replied 2 years ago.
Is the inducer the same thing as the purge blower? I just dont see an inducer on the unit component diagram
Customer: replied 2 years ago.
This is bad, right? Hopefully there is more data to be gathered here!

Attachments are only available to registered users.

Register Here

Attachments are only available to registered users.

Register Here

Attachments are only available to registered users.

Register Here
View Full Image

Attachments are only available to registered users.

Register Here
Expert:  M Oglesby replied 2 years ago.
the inducer motor is the same as the purge blower. According to the last picture that you sent, it is not receiving voltage. This is a indication that the control board is bad.
Customer: replied 2 years ago.
But control board light is green
Expert:  M Oglesby replied 2 years ago.
But it is not sending power to the inducer motor on a call for heat. That means it is bad.
Customer: replied 2 years ago.

Thanks

Expert:  M Oglesby replied 2 years ago.
You are welcome.

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future. Jimmy Bagley, IA
< Last | Next >
  • You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future. Jimmy Bagley, IA
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • gotoman for ac

    HVAC Technician

    Satisfied Customers:

    4657
    51 years of experience install design and repair of all makes and models of AC
< Last | Next >
  • http://ww2.justanswer.com/uploads/SE/ServiceTechRus/2012-6-7_2119_056.64x64.JPG gotoman for ac's Avatar

    gotoman for ac

    HVAC Technician

    Satisfied Customers:

    4657
    51 years of experience install design and repair of all makes and models of AC
  • http://ww2.justanswer.com/uploads/AL/alumalite/2012-5-10_234018_shutterstock506249951forJA500.64x64.jpg Phil's Avatar

    Phil

    Mechanical Engineer

    Satisfied Customers:

    3888
    Retired HVAC/ Electrical & Boiler contractor. Industrial
  • http://ww2.justanswer.com/uploads/skibum0101/2008-12-16_015819_just_answer.jpg Rick Mather's Avatar

    Rick Mather

    HVAC Technician

    Satisfied Customers:

    3132
    35 years experience, HVAC
  • http://ww2.justanswer.com/uploads/RY/Rygis20/2011-5-7_3143_DSC5324.64x64.JPG Matthew's Avatar

    Matthew

    HVAC Technician

    Satisfied Customers:

    1994
    14 years experience in the HVAC field of service, installation, Manual J & D calculations
  • http://ww2.justanswer.com/uploads/KE/kentguidry/2011-9-26_214316_0059.64x64.jpg Kenton Guidry's Avatar

    Kenton Guidry

    HVAC Technician

    Satisfied Customers:

    962
    12 years install/service experience.
  • http://ww2.justanswer.com/uploads/solarman1947/2009-12-13_223915_phpkKBcXq_c2PM.jpg Rick Ridley's Avatar

    Rick Ridley

    UK Heating Engineer

    Satisfied Customers:

    871
    Retired But have had 30 years on the tools, Ex CORGI
  • http://ww2.justanswer.com/uploads/Ironheadfan/2009-12-18_222416_pump_005.jpg Tom's Avatar

    Tom

    HVAC Technician

    Satisfied Customers:

    770
    16+yrs HVAC/R service. Residential Commerical Industrial