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 Tim H. Your Own Question
Tim H.
Tim H., HVAC Professional
Category: HVAC
Satisfied Customers: 3971
Experience:  Experienced in all aspects of HVAC, both residential and commercial.
27228809
Type Your HVAC Question Here...
Tim H. is online now
A new question is answered every 9 seconds

The screen on my Trane XR401 control unit has gone blank.

Customer Question

The screen on my Trane XR401 control unit has gone blank.
I read your response to the person who had the same problem as mine. I just replaced the fuse and the screen is still blank. Any ideas?
Submitted: 1 year ago.
Category: HVAC
Expert:  Tim H. replied 1 year ago.
Hi, I'm Tim and I'm an HVAC expert here to assist you with your questions. Please provide all information I request as it makes it more difficult to troubleshoot something when I'm not there onsite. Essentially, you become my eyes and ears. Thanks for the opportunity to help. At the end of our dialog, you will have a chance to rate my service, but please wait until we are finished and you're satisfied you have all the information you need.Does this unit control a furnace or an air handler?
Customer: replied 1 year ago.
I am a woman, so I do not know. All I know is that I have a TRANE and have an XR401 Confort Control and the screen went blank this morning and I cannot turn my AC on. I read online someone with the same problem and I changed the fuse and I still have this problem.
Expert:  Tim H. replied 1 year ago.
Well, you said you changed the fuse. Which fuse? If you are talking about the one on the board, this would be the unit I am asking about. Is this a gas forced air furnace or just an air handler? In any case, besides the fuse, it could also be a switch turned off to the furnace, blower door not on securely, or even a tripped circuit breaker.
Customer: replied 1 year ago.
I took the panel off that had the 4 screws, so I am guessing this would be the furnace. Then I replaced the fuse that is connected to the two red wires, 5 amp.
The breaker was not tripped because I checked that and clicked them off and clicked them back on. So, it was not the breaker at the main breaker box inside my house.
The door was on securely. I took it off to install the fuse. Do I need to put the door back on before the control panel would come back on? I just changed the breaker and have not put the door back on. Maybe I need to go put the door back on to see if the screen comes on.
Expert:  Tim H. replied 1 year ago.
Yes, door needs to be on because it makes a "power" switch.
Customer: replied 1 year ago.
I will be back then. Give me a few minutes. Thanks.
Expert:  Tim H. replied 1 year ago.
OK
Expert:  Tim H. replied 1 year ago.
Did that work?
Customer: replied 1 year ago.
I got 3 of the 4 screws in with not the right took and AC came on so I went and look at control pad and it was on but when I went to put 4 th screw in it went off. So u took all screws out and I'm on the way to get the right took to out the screws in
Seems like it us young to work but I don't know why ur cut off
Expert:  Tim H. replied 1 year ago.
Great! So it sounds like the fuse replacement worked, then.
Customer: replied 1 year ago.
I hope so but won't know until I get back and put door on
Idk why it went blank while I was putting in the 3rd screw
Expert:  Tim H. replied 1 year ago.
You could have a bad door switch. I'm not sure which screws you are referring to, though.
Customer: replied 1 year ago.
The 4 thst hold the door panel
Expert:  Tim H. replied 1 year ago.
On the door panel, there is a door "switch" that has to be made for the unit to have power. This switch could be bad OR not being made by the door and this would cause a blank thermostat.
Customer: replied 1 year ago.
I will let you know if it works
I'm on way back home
Expert:  Tim H. replied 1 year ago.
OK
Customer: replied 1 year ago.
I got it out together and it would not vibe on so I think u said it might be a switch?
Expert:  Tim H. replied 1 year ago.
Very possible. The switch affects power and thus you would have a blank screen on the thermostat.
Customer: replied 1 year ago.
Is that most likely the problem?
Does that require an AC person or could a normal person fix it?
Expert:  Tim H. replied 1 year ago.
Well, if you have a voltmeter, you can check it.
Customer: replied 1 year ago.
What do I check?
Expert:  Tim H. replied 1 year ago.
You can check from ground to both sides of the switch teminals for voltage with switch pushed in. You should have 120 volts on both sides. I'm going to be signing off now, but we can continue tomorrow.
Expert:  Tim H. replied 1 year ago.
I'm back for a few hours, so let me know if you have more questions/need additional help.
Customer: replied 1 year ago.
I had an AC man out yesterday and the problem was that the drain line in front of unit, inside, was stopped up so he had to replace the PVC pipe.
Expert:  Tim H. replied 1 year ago.
Is this unit in an attic?
Customer: replied 1 year ago.
The unit in attic and furnace in side house.
The pvc replaced was in house.
Expert:  Tim H. replied 1 year ago.
OK, so overflow pan underneath attic unit was probably full and this, in turn, made a float switch which cut power to the unit. I wish I had known this was an attic unit. I would have had you check overflow pan.
Customer: replied 1 year ago.
Furnace us inside house a
Expert:  Tim H. replied 1 year ago.
The plugged PVC pipe, made the pan fill up and this in turn caused it to lose low voltage power.
Customer: replied 1 year ago.
The AC man did not go in attic so maybe there is no unit in attic
I have 2 Inuits and one of the units is in attic so in guessing this one is nit
Expert:  Tim H. replied 1 year ago.
Either way, the only way a plugged PVC line could cause thermostat to be blank, is if some sort of safety switch was tripped when line plugged up. Anyways, glad you're up and running. Troubleshooting over the internet can be difficult, but I've successfully helped many people get their units up and running.
Customer: replied 1 year ago.
Thank you
Expert:  Tim H. replied 1 year ago.
Yes, good luck! Thanks for using Just Answer and please don't forget to rate my service as that's how experts get paid (thanks in advance for any bonus left). Otherwise experts work at their own time and expense. Feel free to post back with any additional questions.
Expert:  Tim H. replied 1 year ago.
Did you have additional questions?

Related HVAC Questions