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 Matthew Your Own Question

Matthew
Matthew, HVAC Technician
Category: HVAC
Satisfied Customers: 1998
Experience:  14 years experience in the HVAC field of service, installation, Manual J & D calculations
6927568
Type Your HVAC Question Here...
Matthew is online now
A new question is answered every 9 seconds

I have an Amana Furnace/AC with White Rogers 50A55-288 control

Resolved Question:

I have an Amana Furnace/AC with White Rogers 50A55-288 control unit. I was using the AC which seemed to be working fine but then later the Furnace Main Fan stopped running. Condenser unit fan still runs but not sure about the compressor (I believe it is running). I tried running the fan with just the thermostat fan run function ....no go. Also attempted to do so by running on the heat cycle ...no go. Swapped thermostats with identical unit from my main floor furnace/AC....no go. Jumpered 120 volt directly to the fan motor Hi speed winding and the fan runs no problem. (Obviously, I also had the fan cabinet interlock jumpered out when I was trying all these different things.
One of the two 24 volt control transformers doesn't have any voltage coming to it in any flavor of the above tests and it appears to get it's power out of the control module. Is the control module the problem (no diagnostic lamp codes...led is dark at all times)?
Submitted: 4 years ago.
Category: HVAC
Expert:  Matthew replied 4 years ago.
Chat Conversation Started
Matthew :

Not sure why you have 2 transformers unless you have a humidifier or U.V tied into the system using the other transformer, but these transformers are fed 120v from the board high voltage terminals and then in turn the 24v from the transformer goes back to the board to power all of the 24v circiuts. If you have 120v going to the transformer but no 24v coming out of the transformer then it is bad. If you have 24v coming out of the transformer but no 24v on any of the functions coming out of the board using 24v like the thermostat (should have 24v between R and C at all times) then the board is bad or the 3 or 5 amp fuse on the control board is blown.

Customer:

Matthew,


 

Matthew :

yes?

Customer:

I think you're correct the one transformer powers the humidifier valve/control.

Customer:

I'll verify that.

Customer:

What can keep the fan from running when I use the "run" over-ride on the thermostat?

Matthew :

No power to the motor because of a bad control board, bad transformer, or the 3 or 5 amp fuse on the board is blown

Matthew :

You said that you can manually jump 120v to the motor and it runs so we know that it simply is not getting the call to run from the board

Customer:

Fuse is good. Transformer is good so based on your input it must be the board...right?

Matthew :

One final test will tell us

Customer:

and that is?

Matthew :

take a jumper wire and connect the G terminal on the control board to the R terminal on the control board and then press the door saftey switch in

Matthew :

If the motor doesn't come on bad board. If the motor does come on bad thermostat (or thermostat wire)

Customer:

OK, I'll try that and let you know in a few minutes....It's hot in the attic so I'll try to be quick.

Customer:

Looks like bad board....no joy on the motor running jumpering G to R.

Matthew :

yeah if you hot wire and the motor runs with direct power then there is no problem with the motor or the capacitor. Jumping G and R bypasses the thermostat so if there is 24v at the R and C terminal and the motor doesn't run then it is the board.

Customer:

OK, thanks. Any recommendations on where to get a good price on board relatively quickly?

Matthew :

If you buy it online your going to have to wait for shipping. Best bet is to call a Tech most of the good ones carry a universal board for these 50A55 boards.

Customer:

OK, thank you...have a great (remainder of) day!

Matthew :

ttp://www.emersonclimate.com/Documents/White-Rodgers/instruction_sheets/0037-6265.pdf

Matthew :

that is the board that shows up as the replacement for the 288

Customer:

Thanks again.

Matthew, HVAC Technician
Category: HVAC
Satisfied Customers: 1998
Experience: 14 years experience in the HVAC field of service, installation, Manual J & D calculations
Matthew and 9 other HVAC Specialists are ready to help you

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
 
 
 
Chat Now With A HVAC Technician
Matthew
Matthew
HVAC Technician
1998 Satisfied Customers
14 years experience in the HVAC field of service, installation, Manual J & D calculations