Have HVAC Questions? Ask an HVAC Expert for Answers
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!
Here's what I'd like you to do to start out with: call for heat and go down by the furnace, take the cover off near the burners and watch it light. Does it light OK? Burner flames look normal? As it heats, do the burners stay on the whole time, or do they go out? And if they do, are you getting an LED flash code? Once you've done all this reply back to me and we can go from there. Thanks.
OK, but have you done what I asked? I need you to kind of be my eyes and ears here since I'm not onsite.
I need you to actually stay there a while and watch it. I want to know if, during the course of a call for heat, the burners saty on and look normal the WHOLE TIME.
OK, but after 10 minutes, had the house reached setpoint?
OK, I guess that's what I'm getting at. Lets say you watched it for 10 minutes and everything seemed normal, but then after you left, burner starting going off and on because of some error. That's why I'd like you to watch it the whole time.
Thanks for the pic. I would watch it at least a half hour. Another way we can approach this: inside your furnace on a tag will be your make model and serial number as well as some other information. Somewhere on there will be a thing called "temperature rise". Lets just say it says 65-85. So what that means is that the air coming out of your furnace (above the A-coil for your AC) should be 65-85 degrees hotter than air coming in. If you can obtain an accurate probe type thermometer that will read, lets just say up to 200 degrees and check the temp of the air coming into your furnace )right around whrer the furnace filter is) and then the air blowing into your house (above the A-coil) and see if there really is a temperature rise that coincides with your stamped temp rise.
Well you want to measure the supply air right above the coil.
And that would make sense, because if the secondary heat exchanger is cracked, a lot of the combustion products (and heat) would end up outside your heat exchanger where you wouldn't want it. It's funny you didn't get a pressure switch code, though, if that is bad.