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Brian HVAC Guy
Brian HVAC Guy, HVAC Technician
Category: HVAC
Satisfied Customers: 797
Experience:  I have been an HVAC/R mechanic/technician for 30+ years.
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I tried replacing my Honeywell thermostat with a wifi one.

Customer Question

I tried replacing my Honeywell thermostat with a wifi one. Could not get the wires to fit. Put original back on wires in the same place and cooling won't come on. I can turn fan on but other system won't run. It displays the message system wait. It's been in system wait for 30 minutes now. What the heck ?? It's a brand new house.
Submitted: 1 year ago.
Category: HVAC
Expert:  Brian HVAC Guy replied 1 year ago.

Hi I'm Brian and I'm here to help!

Can you please send me the model number of your old thermostat you are trying to get to work. Also what the make and type of ac and heat system you have? e.g. Carrier split system, Trane Heat pump split system etc...?

Thanks,

Brian

Customer: replied 1 year ago.
It's a Trane model 4twb3030c1000aa. Mfg date 12/2014. Heat pump system brad new house.
Expert:  Brian HVAC Guy replied 1 year ago.

Great, thanks for that, and the model of the Honeywell thermostat model number?

Customer: replied 1 year ago.
Honeywell th832or1003
Expert:  Brian HVAC Guy replied 1 year ago.

Awesome, let me pull up the manual for your thermostat. It's possible the existing thermostat lost it's installer set up programming while it was uninstalled. Did you go back into installer set up and check the settings?

Customer: replied 1 year ago.
I am panicking. One of the wires arced when I tried to install the new ones cover. I turned off power and put old thermostat back. Have flipped all breakers on and off. Fan will work but nothing else. Just system wait message
Expert:  Brian HVAC Guy replied 1 year ago.

Ok thanks, ***** ***** saying the indoor blower operates when you set the thermostat fan mode from Auto to ON?

Customer: replied 1 year ago.
intaller setup just bring up a place to enter a password
Expert:  Brian HVAC Guy replied 1 year ago.

Also, if you made the request for a phone call from me, I currently don't have that option available. I apologize for the inconvenience.

Customer: replied 1 year ago.
It says installer options. Press enter. Then wants a 4 digit password
Expert:  Brian HVAC Guy replied 1 year ago.

Ok, let me bring up the manual. In the meantime, the default Honeywell installer setup password ***** ***** 4 digit date code that's on the back of the thermostat section when you pull it off the base.

Customer: replied 1 year ago.
I hope it's just the thermostat. It has 4 aa batteries in it. I took them out and rebooted but same thing
Customer: replied 1 year ago.
Okay. I a, in the installer menu. The password ***** Now what ??
Customer: replied 1 year ago.
Thank you so much so far !!!! We might get this fixed ???!!
Expert:  Brian HVAC Guy replied 1 year ago.

If you can run the indoor blower with the fan mode switch on the thermostat, we should be ok. Give me a moment to review the installer set up settings. I'll be right back!

Customer: replied 1 year ago.
Thank you !!!!
Customer: replied 1 year ago.
Are you still online ? I'm in the installer menu but idk what to do ?
Expert:  Brian HVAC Guy replied 1 year ago.

You're welcome! It took me a bit. It's been awhile since I worked on this thermostat. I believe I have the right manual for it. Do you have more than 2 wires or many wires connected at the thermostat?

Expert:  Brian HVAC Guy replied 1 year ago.

Sorry I was reading the manual. This is a pretty complicated thermostat!

Customer: replied 1 year ago.
It has 6 wires connected. I took a pic with my iPad and put the wires back where I took the, off.
Customer: replied 1 year ago.
Should I mess around in the installer menu ?
Expert:  Brian HVAC Guy replied 1 year ago.

Oh, I wasn't to worried about whether you wired it right. I assumed that unless we figured out differently! I just wanted to know if the thermostat was communicating with another EIM module at the air handler or not and the amount of wires tells me! Ok scroll down to ISU 200 and tell me what it's set at in the installer set up?

Expert:  Brian HVAC Guy replied 1 year ago.

Also, do you know if you have any Redlink devices in your system? like an outdoor sensor or remote control for the thermostat?

Customer: replied 1 year ago.
I scroll and it says intaller setup or intaller test or data logs or wireless manager or reset to defaults or device info. I have to select on of those. I don't see ISu 200
Customer: replied 1 year ago.
No. No outdoor sensors or remotes
Expert:  Brian HVAC Guy replied 1 year ago.

I'm sorry, I thought you were in the ISU already. Select installer setup.

Customer: replied 1 year ago.
Ok. I'm in installer setup
Expert:  Brian HVAC Guy replied 1 year ago.

Ok great! Scroll down to the ISU 200 first and that will tell us where we stand. Use Next or Back as you need to.

Customer: replied 1 year ago.
Wondering if reversing valve setting is correct ?? It says o (o/b on cool. Or o (o/b on heat ?
Customer: replied 1 year ago.
I'm stuck. What is ISu 200 ?? I don't see that
Customer: replied 1 year ago.
Do u mean installer setup ?
Expert:  Brian HVAC Guy replied 1 year ago.

Yes, in the installer set up. You should see an ISU number on the screen and a selection value.

Expert:  Brian HVAC Guy replied 1 year ago.

When you got into the installer set up it should have started at ISU 101 and pressing next should scroll to the next one.

Customer: replied 1 year ago.
No I select intaller setup and it says residential or commercial
Expert:  Brian HVAC Guy replied 1 year ago.

Ah, select residential! Sorry.

Customer: replied 1 year ago.
Now I see it says 101
Customer: replied 1 year ago.
Now I am at ISu 200 !!
Expert:  Brian HVAC Guy replied 1 year ago.

Now use the up and down arrows next to the 101 to go to 200 and tell me what it says for 200

Expert:  Brian HVAC Guy replied 1 year ago.

Awesome! what's it set at?

Customer: replied 1 year ago.
It says heat pump
Expert:  Brian HVAC Guy replied 1 year ago.

Perfect now go to 201 and what is that?

Customer: replied 1 year ago.
Air to air heat pump
Expert:  Brian HVAC Guy replied 1 year ago.

Perfect! now 206...

Customer: replied 1 year ago.
O (o/b on cool
Customer: replied 1 year ago.
Reversing valve
Expert:  Brian HVAC Guy replied 1 year ago.

Perfect again! It didn't lose it's setup so now you can press Home or Done

Customer: replied 1 year ago.
Okay ??
Expert:  Brian HVAC Guy replied 1 year ago.

Now you should go through the process of setting the date and time

Customer: replied 1 year ago.
Now what ? Thank you by the way
Customer: replied 1 year ago.
Ok
Customer: replied 1 year ago.
It was already set correctly
Customer: replied 1 year ago.
I changed it by one minute anyway !
Expert:  Brian HVAC Guy replied 1 year ago.

You're very welcome! We'll figure it out! At the very worst there could be a blown fuse in your air handler but it doesn't seem like it! So now hit home and set the thermostat on cool and low enough to run. That's good that you changed the time a bit, it forces a restart!

Customer: replied 1 year ago.
It still says system wait !
Expert:  Brian HVAC Guy replied 1 year ago.

Ok that is normal but only for 5 minutes. Can you change the fan mode switch to on and tell me if the indoor blower runs and you get airflow through your vents please?

Customer: replied 1 year ago.
Now the indoor fan will not turn on either. It did earlier but now I've screwed that up Too !!
Customer: replied 1 year ago.
That's been my problem. It just stays stuck in system wait
Expert:  Brian HVAC Guy replied 1 year ago.

Ok so the possibility is that since you saw that little spark, you may have blown a low voltage fuse on your air handler control board. Are you comfortable taking the blower panel off your air handler and looking on the control board for a 3 or 5 amp automotive style blade fuse?

Customer: replied 1 year ago.
Expert:  Brian HVAC Guy replied 1 year ago.

That will probably take care of it. It appears your thermostat is fine! Trane is awful at posting their literature online so I don't have access to the service manual but if you give me the model number of the air handler, I'll see if by slight chance I can find it. Sometimes on certain models I get lucky and find one.

Customer: replied 1 year ago.
What will it look like ??
Customer: replied 1 year ago.
I see a 5 amp fuse but it looks ok
Expert:  Brian HVAC Guy replied 1 year ago.

Turn the power off and look carefully at the fuse! Sometimes they don't look blown but they are!

Expert:  Brian HVAC Guy replied 1 year ago.

Pull it out to look at it after you turn the power off!

Customer: replied 1 year ago.
Ok but the indoor blower was working earlier when I first contacted you. So I'm ouzzled
Expert:  Brian HVAC Guy replied 1 year ago.

I'm not sure what's up with that. That is odd indeed.

Customer: replied 1 year ago.
It looks fine. Took it out and held up to light. It's fine.
Expert:  Brian HVAC Guy replied 1 year ago.

Ok, are there any led's lit on the board when the power is on?

Customer: replied 1 year ago.
No. I don't see any
Expert:  Brian HVAC Guy replied 1 year ago.

Put the fuse back in if you haven't already. It's probably going to be easier to do the next test at the thermostat so button up the air handler, find a paperclip or little piece of wire you can bend into a U shape, go back to the thermostat, remove the face, and let's jumper between some of the terminals and see what happens.....

Customer: replied 1 year ago.
Should I leav the power off ??
Expert:  Brian HVAC Guy replied 1 year ago.

These jumper tests are going to be done with the air handler powered up. It's good if you have a helper to go look outside at the unit. First jumper R to G and tell me if the air handler blower runs. Don't worry about getting shocked, it's low voltage!

Expert:  Brian HVAC Guy replied 1 year ago.

It may spark just a hair when you jumper them. Whatever you do, DON'T jump R to C at any time though!!!

Customer: replied 1 year ago.
Ok. Jumped r across to g. Nothing
Customer: replied 1 year ago.
I know c is Hot
Expert:  Brian HVAC Guy replied 1 year ago.

And you're sure the fuse is ok and the power is on to the air handler? Do you by chance have a little multimeter?

Customer: replied 1 year ago.
I don't have a multimeter.
Expert:  Brian HVAC Guy replied 1 year ago.

Is there anything in the system I'm not aware of? Like a zoning panel or control panel next to the air handler?

Expert:  Brian HVAC Guy replied 1 year ago.

Sorry, I should have asked that way early on!

Customer: replied 1 year ago.
No. Everything was fine. Other thermostat worked. I just could not get it on the wall. The space for wires was too small. So I out old one back on and it started momentarily I think. Then I set it and it went to system wait. Ugh
Customer: replied 1 year ago.
There are two circui breakers on the air handler cover but neither is or was tripped
Customer: replied 1 year ago.
I hear the air handler humming !!
Customer: replied 1 year ago.
I shut power off to it and it quits. It's in the garage
Customer: replied 1 year ago.
Fan in the unit in the garage. Idk if u call that the air handler or not. It's the inside fan unit
Expert:  Brian HVAC Guy replied 1 year ago.

Well, since the thermostat settings are ok and it keeps saying wait, that tells me there is no 24 volts coming into the thermostat. The 24 volts comes from the air handler and that's why we checked that fuse. If there is power to the air handler and the fuse is fine then the only thing left is either the 24 volt low voltage transformer or the control board in the air handler itself (which is very rare that shorting a wire would do that!) It's most likely the transformer. It will require taking some voltage readings in the air handler to confirm. If the transformer is blown on the low voltage side, it will still hum so that's not surprising you hear that.

Customer: replied 1 year ago.
I need to call a hvac guy correct ?
Expert:  Brian HVAC Guy replied 1 year ago.

I would certainly try replacing the fuse first though. I'm tellin ya they can fool ya! They've even fooled me on occasion! If you can get your hands on a meter we can check what's going on in the air handler but unfortunately short of changing the fuse, we've done everything we can do without a meter. FYI they are only about $20 at Wal Mart. Just sayin....

Customer: replied 1 year ago.
Ok. I'm done for tonight. Thank you. I will try a fuse first. Is it an automotive 5 amp ?? Yellow ? Will that work ?
Expert:  Brian HVAC Guy replied 1 year ago.

Yep, it's an ATC5 which you can find at wal mart or any auto parts store. I'll be online tomorrow so give me a shout on this same question and I'll get an email that you left a reply and I'll get back to you as soon as I can! I'm sorry we couldn't get it up and running tonight! At least you know more than you did and got a short lesson in ac low voltage wiring and thermostat setup! :P

Try to have a good night!

Brian

Expert:  Brian HVAC Guy replied 1 year ago.

Good morning! I'm checking to see if you got your fuse replaced and if by chance you got your hands on a meter to see what's going on with your system?

Let me know how I can help,

Brian

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