HVAC

Have HVAC questions? Ask an HVAC Expert for answers

Ask an Expert,
Get an Answer ASAP!

Having problems with heatpump mod. XPO78COOR4DAA4A ser.NOD9734986…

Customer Question
having problems with heatpump mod...
having problems with heatpump mod. XPO78COOR4DAA4A ser.NOD9734986 i reset 24 volt contol voltate and as soon as thermostat calls for cooling transformer trips i traced all wiring and can't find short it seems like it might be the controller board itself thats shorted out but would like to know it there is any way of testing it before replacing it tried to call tech support but get put on hold and never get reply also they don't have a way of leaving call back number
Submitted: 3 years ago.Category: HVAC
Show More
Show Less
Ask Your Own HVAC Question
Answered in 47 minutes by:
6/15/2015
HVAC Technician: airheatman, HVAC Technician replied 3 years ago
airheatman
airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 9,346
Experience: Furnace, A/C and heat pump specialist.
Verified
Hello. My name is ***** ***** I'll do my best to help. Let's get started and see what we can do.About the only way to find the short is to start unplugging components until it no longer trips. I would start with contactors as the coil is pretty common to short on contactors.If we get back to board and with 24v wires coming out disconnected , it still trips, control board is most likely the culprit.
Ask Your Own HVAC Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a hvac technicianLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask airheatman Your Own Question
airheatman
airheatman
airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 9,346
9,346 Satisfied Customers
Experience: Furnace, A/C and heat pump specialist.

airheatman is online now

A new question is answered every 9 seconds

How JustAnswer works:

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

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.

JimmyBagley, 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!!!!

AlexLos 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.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, 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.

EstherWoodstock, 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.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

Phil

Phil

Mechanical Engineer

7,634 satisfied customers

Retired HVAC/ Electrical & Boiler contractor. Industrial

Rick Mather

Rick Mather

HVAC Technician

3,133 satisfied customers

35 years experience, HVAC

Matthew

Matthew

HVAC Technician

2,014 satisfied customers

14 years experience in the HVAC field of service, installation, Manual J & D calculations

Brian HVAC Guy

Brian HVAC Guy

HVAC Technician

1,024 satisfied customers

I have been an HVAC/R mechanic/technician for 30+ years.

Kenton Guidry

Kenton Guidry

HVAC Technician

963 satisfied customers

12 years install/service experience.

Rick Ridley

Rick Ridley

UK Heating Engineer

871 satisfied customers

Retired But have had 30 years on the tools, Ex CORGI

Tom

Tom

HVAC Technician

770 satisfied customers

16+yrs HVAC/R service. Residential Commerical Industrial

< Previous | Next >

Related HVAC Questions
My Lennox heat pump AC condenser unit outside will not turn
My Lennox heat pump AC condenser unit outside will not turn on when the I door thermostat calls for cooling. I have ruled out various parts and problems. The unit works nicely and cools the house if I… read more
airheatman
airheatman
HVAC Technician
6 years college
9,346 satisfied customers
I disconnected an old thermostat to add a new digital. I did
I disconnected an old thermostat to add a new digital. I did not mark the wires and connected the digital by wire color, but now does not turn on the heat or a/c. How can I check the wiring configurat… read more
airheatman
airheatman
HVAC Technician
6 years college
9,346 satisfied customers
I have a nordyne e3eb 015h. Today, the heat and cooling just
I have a nordyne e3eb 015h. Today, the heat and cooling just quit altogether, neither works. I checked the voltage on the transformer and there is no voltage coming out. 240 on bottom, 0 on top. I hav… read more
SWFLHVAC
SWFLHVAC
67 satisfied customers
good morning , I talked with you before about a carrier 48tc
good morning , I talked with you before about a carrier 48tc 4 ton hvac unit , I thought I found the problem and fix it ... wrong. it is back to it 's old tricks, runs good on the heat cycle but as so… read more
Phil
Phil
Mechanical Engineer
Degree, Mech Engr Technology
7,634 satisfied customers
When I tried to start my AC this Spring, it would not come
When I tried to start my AC this Spring, it would not come on from the thermostat. I checked the capacitor. It is good. The contactor is not pulling in. If I push in the contactor with a pencil the fa… read more
ComfortZone
ComfortZone
Associate Degree
515 satisfied customers
I have a Trane XE1000, model number TWR024C100A5. It doesnt
I have a Trane XE1000, model number TWR024C100A5. It doesn't work. When you turn the thermostat to cool it blows hot air. When you turn it to heat or off it blows room temperature air. I've researched… read more
ComfortZone
ComfortZone
Associate Degree
515 satisfied customers
Replaced customers gas furnace with he gas furnace. Customer
Replaced customers gas furnace with he gas furnace. Customer purchased a heatpump, because it was cheap, and now I have to control the system. Does honeywell make a t-stat for heat pumps/gas heat as b… read more
Phil
Phil
Mechanical Engineer
Degree, Mech Engr Technology
7,634 satisfied customers
My air conditioner keeps tripping my 30amp breaker, I have
My air conditioner keeps tripping my 30amp breaker, I have already checked the line wire to make sure there weren't any shorts as well as replaced the breaker. Any ideas?… read more
Regan Land
Regan Land
General Manager
Vocational, Technical or Trade Scho
508 satisfied customers
I have a Lennox CB29 Single Phase Heat Pump System. The Unit
I have a Lennox CB29 Single Phase Heat Pump System. The Unit is approximately 10 years old. My wife and I have lived in our home and have been using the unit for about 8 1/2 years. In November 2009 th… read more
Mr. Jeff Pearson
Mr. Jeff Pearson
Refrigeration Systems
Associate Degree
145 satisfied customers
carrier edge thermostat, not showing outside temperature.
carrier edge thermostat, not showing outside temperature. sensor is wired to a extra black wire on outside heatpump to OAT terminal in thermostat and the other wire to the C junction.… read more
gotoman for ac
gotoman for ac
HVAC Service manager and owner
Associate Degree
4,135 satisfied customers
I switched out the downstairs thermostat with the upstairs
I switched out the downstairs thermostat with the upstairs thermostat, but forgot to turn off the power at the main home switchboard. Upstairs a/c unit is fine. Downstairs a/c unit is dead! There is n… read more
Bart Jay
Bart Jay
Vocational, Technical or Trade Scho
596 satisfied customers
my transformer went bad i replace it and it burnt out right
my transformer went bad i replace it and it burnt out right away my old one had four wires in the back black white yellow blue what is wrong i put a new one and the low water cut off made a loud bang … read more
Joseph
Joseph
HVAC Contractor
Vocational, Technical or Trade Scho
97 satisfied customers
I went to light our low pressure boiler--lifted cover plate
I went to light our low pressure boiler--lifted cover plate in front of the pilot, lit it, it shot up and I jumped--hitting the cover plate with the (looks like a fuse) on bottom. As soon as the fuse?… read more
Mark Henley
Mark Henley
HVAC Controls DDC
3,209 satisfied customers
I have a Hunter 44860 thermostat that has not been working
I have a Hunter 44860 thermostat that has not been working correctly. This past Spring, when I switched from Heat to Cool, my blower fan ran CONSTANTLY. I called out a HVAC repairman and they put in a… read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 satisfied customers
Tempstar furnace Model NUGK050MF07. Have burned out two transformers. I
Tempstar furnace Model NUGK050MF07. Have burned out two transformers. I can't seem to isolate what is happening. Replaced first transformer, checked the 24Volt circuit for short circuit. It was o.k. C… read more
Rick Mather
Rick Mather
HVAC Technician
Vocational, Technical or Trade Scho
3,133 satisfied customers
I have a carrier thermostat that has went blank on the screen
I have a carrier thermostat that has went blank on the screen like it has no power. I have checked the circut box there is no problem. It is model TSTATCCNAC01-b or ACB1-B I cant really make out the e… read more
Rick Mather
Rick Mather
HVAC Technician
Vocational, Technical or Trade Scho
3,133 satisfied customers
I am an owner of a restaurant we have a Trane Voyger model
I am an owner of a restaurant we have a Trane Voyger model #YCH241C3H0CA SER #430100848D MY QUESTION IS IT SEEMS LIKE THERE IS NO POWER GOING TO IT AT ALL IT DOES NOTHING THERMOSTAT IS OK CERCUIT BREA… read more
Rick Mather
Rick Mather
HVAC Technician
Vocational, Technical or Trade Scho
3,133 satisfied customers
I have Honeywell stat, new system (~3yo) Ambient temp reads
I have Honeywell stat, new system (~3yo) Ambient temp reads higher than whait it is, as room cools, ambient incr. AC runs all the time. Circuit board issue? How do I get it off the wall?… read more
drcool299
drcool299
shop owner
Bachelor\u0027s Degree
22 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x