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BillyHvac, Journeyman HVAC Tech
Category: HVAC
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Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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I have a Honeywell TH3210D1004 Thermostat and a carrier high

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I have a Honeywell TH3210D1004 Thermostat and a carrier high efficiency heat pump? (I think , I included pics of everything), here's the deal I wired everything up and when I cut the circuit breaker back on the one that says "Heat" arcs outs and breaks off. I need help here...

here are the pics
You must have a short in the furnace if that breaker is indeed for it. You will need to do basic investigation here to uncover the short as that should not be difficult since it is tripping the breaker immediately. A low voltage wiring issue is not going to trip a breaker.

I can only tell you what to do here- you will of course need to do with the answer what you see fit.
Customer: replied 5 years ago.
Ok well at this point given the outside heat here, i dont need the furnace, is there a way to just get the AC going?
not unless you find the problem in the furnace as that is what blows the air regardless
Customer: replied 5 years ago.
Ok well im pretty handy so im sure if you guide me i can fix it...lets do it..
You need to do what I said before. Look for the short. Disconnect wires as needed until the breaker does not trip.
Customer: replied 5 years ago.
so do i look for the short at the thermostat, or do i need to tear apart the unit outside?
Customer: replied 5 years ago.
Relist: Incomplete answer.

can you do a hands on test at the thermostat?


Customer: replied 5 years ago.
If I am guided Im sure I can...what tools etc do i need?
right now no tools..

remove the red and green wire from the thermostat sub base.

Turn all breakers on..tell me if they stay reset.

Then touch the red and green wire together and tell me if breaker trips

Customer: replied 5 years ago.
circuit breaker still arcs out even when the wires are not touching
Thank you.

have you had an issue recently or changed the thermostat?

did unit work with old thermostat?

Customer: replied 5 years ago.
we were hit by a tornado 1 year ago, and I have had problems ever since with the heat and the a/c. i have 2 units one for upstairs and one for downstairs. The heat wasnt working on the one downstairs so i put the thermostat from upstairs on the one downstairs and the heat would work but the thermostat didnt kick the heat off when it reached preset temp. Now I tried turning on the a/c today and it does nothing. I looked all over online for wiring diagrams to assist me, but to no avail. Now I'm assuming I have a bad circuit breaker??? We are really just very pinched for funds as I lost my job last year bc of the tornado, so doling out alot of money for an HVAC tech isnt feasable at this time...

Ok...remove all wires from thermostat and dont let them touch....tell me if breaker still trips

Customer: replied 5 years ago.
removed all wires and it still wont reset

this is something that is a direct short to ground in the air handler itself.

The air handler is likely 220 volts so care must be taken.

Leave breaker off...remove front door..check all wiring and parts for burned or arced spots..whatever it is is in the 220v circuit...which means main power wires, relay or motor.

Customer: replied 5 years ago.
ok i put a link to a pic of the unit, when you say front door, can you look at the pic and tell me in relation to the pic which "door" you are talking about? thanks actually here is the link to the pic
Customer: replied 5 years ago.
ok I pulled the door off, I don't see anything burnt or arced out. I the pulled the 2 service disconnects and tried the circuit breaker and it works fine. Could one of the fuses in the service disconnects be bad?
Can you take pic inside air handler and post?

Customer: replied 5 years ago.
already did... here they are...
This pic

the component on the that burned marks in the center?
Customer: replied 5 years ago.
upon closer inspection it does appear to be burnt, it also pushes in almost like it were a set of points... it has 2 contact points and both appear to be burnt around the edges...

this could be the issue..or be burnt because of another issue. Any chance you have a meter that measures ohms or resistance?

Customer: replied 5 years ago.
i do have one, already have it out...
do you have a setting that makes a tone when the leads are touched together?

Customer: replied 5 years ago.
no it doesnt make any sounds, when i touch the leads together with the setting to Ohms, the needle just moves...

Ok, that will work



turn breakers off. the on the relay that is burned..there are 2 wires that come to as from main power and then wires leave it and go to the compressor.


Touch one meter lead to the power side on one terminal and then touch the metal cabinet with the other lead. tell me if needle moves.



Customer: replied 5 years ago.
ok in relation to the pic, i touched the black lead and then cabinet, needle went to 0 ohms, then i touched the blue wire lead, same thing ohms to yes the needle did move

ok, now this may be tedious..


we want to remove a component at a time from the syatem while ohming out the circuit.


Ex....mark all motor wires and unhook..then ohm...if still moving...the unhook from a relay and ohm...the remove wires from compressor and ohm..look for domed tops on the capactiors (the round cannisters the size of a pop can).


Eventually you will get no needle movement to ground....this will identify the last item you unhooked as having the short.



Customer: replied 5 years ago.
ok what do i touch the leads to, the wire i unhook or the component after the wire is removed??

either actually.


Lets say you remove 3 wires that attach to would put one lead on the motor wire and the other to that all the motor wires...if there is no needle movement then the motor is not shorted..


Then remove wires from compressor and test compressor to ground.


Plus I am available for 30 days to help..



Customer: replied 5 years ago.
ok reference this pic

i unhooked the blue wire, checked the wire and the lead it was connected to, needles moves both times, i then unhooked the black wire next to it and the needle moves on the component but not the wire. I removed the other wires on this same component and the needle didnt move on any of i may be lost... i also looked at this component and dont see any bulging of any kind...

so does the needle move on just the component?



Customer: replied 5 years ago.
yes just on the component i removed the wire from

Thank you.


Then this would mean you daodged a bullett.


This is a common part to short. It is called a contactor. Make sure all wires are identified and marked. Remove contactor and swing by a local cooling shop and get a new one.


Let me know if you need help installing the new one.



Customer: replied 5 years ago.
ok, so I am going to remove this part in the bottom left of this pic?


now as far as my thermostat wiring as per pic

does it look correct... i also noticed that the wiring color on the outdoor unit are different then what i had hooked up for instance, the blue wire on the outdoor unit is hooked to the "Y" terminal, do i just need to match what is on the unit as far as wiring goes?


Very observant....the terminals outside are copied to the thermostat. And yes the control you pulled wires off from and still read a needle movement will be the unit to replace.

Customer: replied 5 years ago.
ok thanks, XXXXX XXXXX i contact you again after i put this part on should i have any more difficulty?

You just respond to this same thread.


You have 30 days of follow up after accept is clicked....this should give us good time to get it solved.



Customer: replied 5 years ago.
ok thanks Billy, very helpful...lets hope we're cooled off again, I'll let you know how it went


Ok, if you can get the part tomorrow just respond and let me know.



Customer: replied 5 years ago.
ok i replaced the contactor and the circuit breaker still trips???

was there wires attached to the contactor when you ohmed it out and the needle moved?



Customer: replied 5 years ago.
yes i took the wires off one at a time and ohmed each contacted, thats when i had gotten to the black wire on the bottom


Do you have electrical tape?



Customer: replied 5 years ago.
yes somewhere ill have to find it, i have gorilla tape that would prob work??



Start at the compressor and follow the wires back to the contactor (part replaced)


Take the wires off that go to the contactor.


You will see 3 wires leave the compressor and 2 go to the contactor and one to the pop can size cylinder. We want those 3 unhooked and taped just well enough so wire ends are covered.


Then turn on and tell me result.



Customer: replied 5 years ago.
ok how do i know which ones go to the compressor?? if u can ref this pic

Look in the section under the fan in the top.


Down at the bottom you will see a "can" that is the size of an oversized paint can


It will have copper pipes attached to it and wires out of the bottom.....3 of the heavy wires will lead back to the part you replaced and the capacitor.



Customer: replied 5 years ago.
ok i think im going to have to take more panels off bc there isnt anything but wires, components and boards where I am looking.... I will take a pic of what I see... heres the pic


The compressor will be directly under the fan motor in the top of unit.



Customer: replied 5 years ago.
ok it was my best guess, but i un hooked a large yellow wire on the left hand side of the contactor that led to the capacitor, i unhooked a large red one that was connected to a black one and the red part led through a hole at the top towards the compressor (it was on the top right position of the contactor), then i unhooked the purple one on the bottom right of the contactor, i put the service disconnects back in and the circuit breaker still trips... am I guessing that we are isolating the part that is bad??? would it help to disconnect everything and hook them up one wire at a time??

Believe it or not it is starting to fall together. Now...when you first said a breaker labeled heat trips....


Is that the only breaker to this unit?


And also, you see where the main power comes in the unit at lower right...then 2 big black wires attach where it meets up with 2 big yellows and 2 more blacks?


I need a full pic of the area to the left....showing the big wires that lead there.



Customer: replied 5 years ago.
ok, no it is not the only breaker, there is one labeled "A/C" and it doesnt trip... I have taken pics of the whole lower part of the unit...

this is the right bottom part of the unit...

this is the lower left part of the unit...

and here is an overall view of the bottom part of the unit...



do this.


Put all wires back in unit. Turn off/leave off the heat breaker.


Go to thermostat and have all wires hanging loose but not touching each other.


Have the AC breaker on.


Take the red wire at thermostat and the green wire and twist them together.


Tell me if fan kicks on.



Customer: replied 5 years ago.
all wires back on, fan motor does come on when i touched the green and red together...


Thank the twist the red, green, yellow and orange (wire that was on O)


do this with the ac breaker off...then turn on after wires are connected.



Customer: replied 5 years ago.
ok, the yellow wire on the outside unit isnt connected to anything, there is a blue wire in the "Y" position, should I use it as the yellow wire instead??

correct...I forgot about the blue being yellow....good catch



red, green blue orange

Customer: replied 5 years ago.
ok my red wire broke off and there wasnt enough to pull through so exchanged it for the yellow wire on the outside unit, so now Red=Yellow...

I twisted them together and turned on the breaker and nothing happened... the breaker did not trip either...

I am betting the yellow is bad..since it was swapped with blue.


take the thermostat wires off at outdoor cicuit board....breaker for ac on..use short wire an cross r to y terminal and tell me what happens



Customer: replied 5 years ago.
ok, i also just took a pic of a switch that I flipped before I started talking to you yesterday, its on the top left of the pic, when i switched it yesterday there was no way to turn it back the other way, i just noticed however that it is back to a white position... heres the pic

ok now i'm going to take off the wires and do as you said...
Customer: replied 5 years ago.
ok now i'm confused you said to take "ALL" the wires off of the board outside, correct? and then just jumper the "R" and "Y" correct?... i'm asking bc it appears that there are 2 large gauge wires going to the board one on "C" and one on "W2" and it is a large white wire...


All the wires on the R, G, Y,W2 C etc...are all signal wires from the thermostat.


Label what went to what terminal. Remove all. Juper r terminal to Y and tell me if compressor and fan in top start.

Customer: replied 5 years ago.
ok removed all wires, jumper "R" to "Y", turned on breaker, nothing happened..


Now at circuit board...R to G again should do fan



Customer: replied 5 years ago.
"R" to "G", nothing happened

but from inside r to g made fan run right?



Customer: replied 5 years ago.

This pic


upper compartment far left..big block transformer far left is a rocker switch. press that and see if it was tripped.



Customer: replied 5 years ago.
this pic

yeah thats what i was talking about a few messages ago...
correct..I see the button on upper left is tripped..reset and try r to g at board again
Customer: replied 5 years ago.
ok reset the switch, jumper "R" to "G", still nothing... i am using a large gauge wire bc thats all i could find, should that make a difference???

and ac breaker is on?



Customer: replied 5 years ago.
yes it is

and small trip switch on transformer still reset?


And can you read 24v ac at terminal R and C (not G this time).



Customer: replied 5 years ago.
yes switch is reset, and there is 24ac from "R" to ground only, nothing on "C" to ground



With meter lead on R and meter lead on C was there 24v?



Customer: replied 5 years ago.
yes there was


The terminals you have on the circuit board...


are they R, Y, G, O, C, W, W2?

Customer: replied 5 years ago.



I know this is tiresome and redundant but I want to be sure...and careful.


now try jumping r to o and tell me if you hear a click



Customer: replied 5 years ago.
yes i heard a buzz for about 1 sec then a click




now try R to W2



Customer: replied 5 years ago.
ok R to W2, nothing happens


Now...we know the reverse valve activates

We know we have 24v


Now try R to Y again and then R to G again.


but this time ...actually install the jumper in place on the screws and tighten and wait a couple minutes to make sure we get by the delay timer if present.


The only thing we DONT want to do is short R to C or the transformer will trip again.

Customer: replied 5 years ago.
Ok R to Y the fan on top of unit kicked on...

and R to G, waited about 5 min, nothing happened


Rats..we are so we know compressor and fan are active.


Can you see into the blower area where the fan is that circulates air through the duct?



Customer: replied 5 years ago.
not without taking a panel off

The part you put in..if you press the center down does blower start?



Customer: replied 5 years ago.
theres nothing to press down on this replacement part, this was not an exact replacement apparently they dont make the part I had anymore

is there a small plastic cover over the center?



Customer: replied 5 years ago.
i took the cover off and pushed the button, and the fan motor on top of the unit kicked on, i dont know if the blower motor kicked on or not...

Is there any way someone inside can verify if air came out of register?


We are at the end here and I just need to be sure.



Customer: replied 5 years ago.
yes there is air coming out of the register
Customer: replied 5 years ago.
yes there is air coming out of the register

did you forget me???
Customer: replied 5 years ago.

very sorry, had an emergency. I work on hospital equipment and had a chiller for an MRI machine go down.
 the circuit board wire a jumper from R to Y...tell me if outdoor unit fan in top and the blower for registers runs. Then if so..wire R to Y and Y to O. Tell me if it ac's..if so we are ready to wire thermostat for cooling.



Customer: replied 5 years ago.
no problem, I work as a CT Technologist so I know the deal.. we did the R to Y earlier and I had to push in the button on the contactor, do you want me to proceed to your next step...
Yes please...I want to ensure first that R to Y actually turns on the fan in the top and the blower for the registers...if that works we will add the O terminal.
Customer: replied 5 years ago.
R to Y turns on fan but not blower, nothing coming through the registers...

Thank you,


and last time for this...R to G just as a last effort on that circuit.



Customer: replied 5 years ago.
ok R to G does nothing unless I push the button on the contactor

when you press in contactor what all runs?



Customer: replied 5 years ago.
i dont have anyone here to check it but before the blower and the fan ran...




give me a model number from the unit and I will see if we can make do.



Customer: replied 5 years ago.
hmmm... the data sticker that was on it is gone, is there somewhere else I can find the model number??



see this pic but this time we are looking at the relay above the part you replaced. It has 2 black wires, a red wire, and then 2 smaller wires at the bottom you see this and understand which part I refer to?



Customer: replied 5 years ago.
yep, got it

AC breaker off.


pull the 2 black wires

we want to contact these 2 wires.

Use a small nail that slides into each end or a piece of paper clip..tape the joint so no metal is exposed. The goal is to have these 2 wires off the relay and wired to each other.


Then turn ac breaker on and tell me if fan starts.

Customer: replied 5 years ago.
ok 2 black wires from the top of relay taped together, nothing happens unless i push the button in on the contactor, then i can only tell that the fan on top of the unit runs, dont know about the blower

I see the wiring has been changed...brown to blue and a spliced red..


Now put a jumper (screwed into the terminals) on R and Y with the ac breaker off.


Then turn on breaker..go inside and check register.



Customer: replied 5 years ago.
fan motor and blower run

now add a wire from Y to O.


turn breaker back on.


tell me if it cools out of register


Looks like some "rigging" has been done to this unit...

Customer: replied 5 years ago.
theres definately air coming out of the registers, its quite hard for me to tell if it is refrigerated air or not, its pretty hot in here so anything feels cold...
feel the air coming out of the top of the unit outside. That fan should be blowing some hot air upward....
Customer: replied 5 years ago.
it doesnt feel hotter than the outside air, is that whats pulling air through the return?

that fan should be cooling the freon as it circulates through the system.


Unhook O terminal and tell me if it feels the same.



Customer: replied 5 years ago.
ok on checking it again, its definately not cooled...

now give a close up pic of the pop can looking items (capacitor)



Customer: replied 5 years ago.
ok, the air def feels hot coming out now... hold for a pic...
ok,,,,this means the reverse valve is working deenergized it heaats and energized it cools...
Customer: replied 5 years ago.
heres the pics of the capacitor...

Was there a definite difference in the temp out of register when O terminal unhooked?

And is the filter clean?



Customer: replied 5 years ago.
yes there was, i removed the filter earlier yesterday when i started this...

Here is what I need now.


Hook O terminal back up. Let it run for a bit..then take a temp coming out of register and tell me if it is 15 degrees cooler than the room temperature.


Thanks for hanging in there...most CT guys I know are not so patient....

Customer: replied 5 years ago.
ok can i just put the thermostat over it, i dont have a thermometer...
Customer: replied 5 years ago.
ok i put thermostat over register, it started out at 75 and it now show 99


What is room temperature?



Customer: replied 5 years ago.
room temp is about between 75-80, we have fans running in the windows...

Is O terminal wire still attached?



Customer: replied 5 years ago.


Ok summary:


I do not know what was done with the wiring of the red, brown and blue control wires but it involeved the indoor blower relay.


We by passed that relay to allow the blower to come on with a call for cooling (R to Y).

With the relaay bypassed and the compressor, outdoor fan and indoor fan running we should have a discharge temperature of at least 15 degrees cooler than the air being sucked in.


We know the motor works but has been rewired, we know the fan in top works, we know the compressor works because temp of air is different when O is hooked or not hooked.


So, we have all the major items accounted for. But it appears there is a cooling issue. With O unhooked it goes into heat by default. With O attached it is supposed to cool. With 99 coming out of register shows the air is actually being heated...which leads me to think reverse valve dropped out.


If the R, Y, O is jumped together and the air coming out is warm....we have an issue with either too little freon, or bad reverse valve.


Is it still blowing hot air?



Customer: replied 5 years ago.
it was i turned it off, it was roasting me...

then the reverse valve is stuck, bad etc...


The reverse valve is in the area by the compressor


I hate giving in , as you can tell, but the components are all accounted for...just a glitch left with the Heat/cool reverse valve.


I thank you for your extreme patience, but at this point I would have to recommend a tech to inspect the reverse valve.



Customer: replied 5 years ago.
isthe reversing valve difficult to replace?



If the valve itself needs replaced it means removing freon and brazing in a new valve body.


If it is just the coil on top it is easier.



BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22627
Experience: Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
BillyHvac and other HVAC Specialists are ready to help you
Customer: replied 5 years ago.
well i see that the reversing valve runs between $200 - $500 so I guess we're out we dont have that... I dont start this new job until Mar 26th, of course dont get paid til the 19th of April... Do you know any techs or companies in the Chattanooga area that might work with us?


I really apologize but I have no working information of dealer/contractors in your area.


I really wish I could help more.



Customer: replied 5 years ago.
well i appreciate the help... now i gotta try and get the one upstairs going, i think its a simple matter of wires being crossed, its a new unit and always worked fine...its in the attic...

Just remember


red to r = 24v

green to g = indoor blower

yellow to y = ac compressor

Customer: replied 5 years ago.
yeah, this one is new and it looks a whole lot different then what we were working on, 2 sets of wires inside the unit going to the thermostat board... i found a burnt 5 amp fuse so hopefully if i replace it we might be in business... my only question is this, the Y and W1 are jumpered, does the yellow or the white go to that, there also a W2... billy I know you've been on this all day, i really do appreciate it, you certainly gave me more than $38 worth...

This must be a heat pump also.


The biggest culprit of the blown fuse is damge to the thermostat wire that runs from inside to outside.


remove the thermostat wires from circuit board.

replace the fuse

install the R wire and the G wire...test fan on function from thermostat.

if ok add the Y/W1 wire and O terminal wire.



sorry but I have to go offline for a 20-30 minute break.



Customer: replied 5 years ago.
ok dont know if ur back from ur break, i get the fan to run, hook up the others, it blinks "Cool On" on the thermostat, the yellow wire coming out of the thermostat is twisted together with a white wire, so the yellow wire is not actually connected to the board... i also comitted a huge sin, i couldnt find a 5 amp fuse, so i just used a 10 amp, i just figured if it runs then it isnt the problem, i will get a 5 amp tmro...
Customer: replied 5 years ago.
ok it seems to be working fine now, it blinked for a few and now it is on and blowing cold air... i'll just have to wait and see if it shuts off when it reachs the preset temp...

thanks again for all your help... i wish we could have fixed the other one but we cant fix

thanks again Billy


I am glad you got one going at least..if new info pops up let me know.



Customer: replied 5 years ago.
actually i did, i thought the upstairs unit was running fine, however i never checked to see if the fan on top of the unit outside was running, it wasnt so it was basically just the fan running all night...also I didnt leave a tip as I just dont have it at this point, when I get settled I will ask you a simple question and take care of you as I do appreciate all the help...


Is the breaker on to the outdoor unit? Fuses in disconnect box on side of house by unit?



Customer: replied 5 years ago.
yes, i actually just turned it back on and the outside fan is running, warm air out the top, it just doesnt seem that the air is as cold as it should be... perhaps it just needs freon?

Is the filter at indoor unit clean?

Is the underside of the indoor coil clean?

Is the outdoor coil clean?


If those issues are ok then it is likely a loss of refrigerant issue.


As far as tip....dont worry about it as you have already paid more than most.


I thank you.



Customer: replied 5 years ago.
yep, all the filters etc are clean, this unit is in my attic and is new (within 6 years), outdoor unit is clean too... so I guess it freon, is there anyway to really screw up putting refrigerant in, like too much etc...

Yes...putting in freon is a touchy balance. Too much ruins compressor, not enough = no cooling.



Customer: replied 5 years ago.
thanks Billy, also found out last night that I have mice in my air ducts to the unit we didnt get fixed, I wonder if that had anything to do with the unit going bad?? Now I have to get rid of these stinking mice...dont get hit with a tornado, its a

Hopefully you will have a string of goodluck soon...I really wish you well



Customer: replied 5 years ago.
thanks I appreciate it, hey what would i need to recharge my unit? tools etc??


A set of refrigeration gages.

And a jug of R22 refrigerant.


Would help if you knew anyone in the business since to get the r22 freon you must be certified.



Customer: replied 5 years ago.
ok well i guess that kills that was looking at gauges and they are quite expensive anyways... oh well... thx again


It can only get better....good luck in the new job.



Customer: replied 5 years ago.
ok billy, last question, promise...I dont think that refrigerant is my problem... i took a picture of the coils inside the unit in the attic, they are frozen over... i left the access panel off all night...could it be that the blower was sucking air from the hot attic instead of getting from the return air which passes over the frozen coils? if so then i'm just a dumba$$ advise...thanks again

heres the pic of the coils


That would cause the issue..the air is not all forced through the coil thus it mimics a dirty filter or bad blower.


Set fan "on" and run with ac off for 40 minutes. This should defrost the coil,,replace all panels and then try...let me know.