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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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Carrier Performance 93 installed 5 years ago. Last week I

Customer Question

Carrier Performance 93 installed 5 years ago.
Last week I had a new thermostat installed but problem has not been resolved.
Here is the pattern since then:
New thermostat installed Wed March 9th and program set to come on at 5:30 AM during the week and 6:30 on the weekend; however,
• Since then the furnace has come on around 4:00 in the morning on Thursday March 10, Saturday March 12, Sunday March 13, Wednesday March 16, Thursday March 17 and this morning.
• On Wed March 16 at 6:40 PM I tried to increase the temperature by 2 degrees but the furnace didn’t come on. I used the fireplace for the evening.
• On Thursday March 17 in the Am the temperature showed it was set for 19.5 and the indoor temperature was 17.5, but the furnace didn’t come on. I went down and flipped the power off and on and then fan started and then stopped after a minute or so. The heat didn’t kick in. I increased the setting to 20.5 but the heat still never came on. I waited 20 minutes then turned off the
Submitted: 1 year ago.
Category: HVAC
Customer: replied 1 year ago.
I waited 20 minutes then turned off the power again and when I turned it back on the fan came on for a minute then shut down. There was no heat. Several minutes later the flame kicked in and the fan started.
• Today the heat came on at around 4:45 am and showed the indoor temperature to be 18.5 even though the temperature was set for 16.5 (sleeping temperature). I manually turned the temperature down to 17 and the heat stopped. At 5:30 Am the heat came on as scheduled and to the set temperature of 19.5.I thought I would document the pattern to see if that would help explain what is happening. This is very similar behaviour to what was happening before we put in the new thermostat.What do you think we should try next?
Expert:  Tim H. replied 1 year ago.

Hi, I'm Tim and I'm an HVAC expert here to help answer your question(s). Please provide all the information I ask for since I'm not onsite. At the end of our dialog you will be asked to rate my service, but please wait until then and all your question(s) have been answered satisfactorily. If you are not satisfied, I'd appreciate it if you'd tell me why before leaving a negative rating and allow me to continue to work with you until we are able to both agree on an outcome to follow. Thanks for your business!

What is the full model number of the unit? When it doesn't come on, is there a LED flash code?

Customer: replied 1 year ago.
I'm not on site so I can't give you the additional information at this point. I will look tonight when I get home to see if I have an LED flash code.I'm I able to continue this conversation when I get home from another computer?
Expert:  Tim H. replied 1 year ago.

Yes, correct.

Customer: replied 1 year ago.
I'll do that. Thanks
Expert:  Tim H. replied 1 year ago.


Customer: replied 1 year ago.
The furnace is called: Carrier Performance 93, Comfort Heat, Ultra Efficient. Product number: 58MTA060- 12-F-12112, Model number: 58MTA060 -12, Serial number 2904A15549. It was manufactured in 2004 and installed in 2010. I couldn't locate something that looks like a flash code.
Expert:  Tim H. replied 1 year ago.

The flash code will only occur when there's an issue and when furnace shuts down. Take the front cover off and look n the lower panel for a small window through which will be visible any flash code.

Expert:  Tim H. replied 1 year ago.

Find any flash code yet?