Having problems with AC and Bryant furnace

bludog1June 30, 2012

I just had a new furnace Bryant 97% furnace at 120,000 BTU.Model#987ma66120v24. it came with an evolution thermostat and a concentric vent. cost of $5850. My problem is the lennox air conditioner MNHSXA12 048 230 01

that had worked fine in the past isn't working right now I had the people out who put the furnace in come back and they checked AC add freon but said gage read 32 which wasn't good. came back the next day and adjusted the furnace to 400 something that was set at 350 and added a vent to air return by the furnace and said AC now read 40 degrees which was good and left. The AC froze up again. I don't know what to do the AC was working fine last year this year my old furnace went out. Now the AC seems to be working but keeps freezing up? I talked to installer again he said he would come back one more time and check it out. Any suggestions I don't know what to do this is the third time out here he doesn't want to come again . What should I do if he can not fix the problem just gives up and leaves me in this spot

Please help


Please Help


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How old is the Lennox AC? Was the coil changed when the furnace was replaced? If yes, then what is the brand and model number of the new coil?

It sounds like the furnace air blower speed was increased from 350CFM to 400CFM in an attempt to keep the coil from freezing. My first thought is to make sure the Evolution controller is always setting the air flow at 400CFM. This can be checked in the advanced menu.

The problem can also be a low freon charge. A leak may have developed during the installation of the furnace. Did the contractor warn you about this possiblity? Did the contractor suggest changing the AC and coil at the same time?

You must have a big house in a cold climate to have a 120,000 BTU furnace. What was the size and efficiency of the old furnace?

    Bookmark   June 30, 2012 at 2:41PM
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I do have a large house 4,300 sq.feet in the Rockey Mountains
Golden Colorado. The coil was not changed never mentioned.
the AC unit is about 10 years old. The old furnace is about the same size but this one is supposed to be much more efficient. I did have it checked out before I got the new furnace, and the AC was working fine it was the furnace that needed to be replaced. The man who checked it out recommended this company because he was leaving town for a few weeks. So if by chance the coil did get a leak while installing who's fault would that be? would a split cost seem fair? The owner of this company is very nice but seems to be getting tired of the problem.
Thanks for your help

    Bookmark   June 30, 2012 at 4:08PM
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I suggest you talk to the contractor and tell him the AC was working fine the day the furnace was installed. Then ask what is the root cause of the coil freezing. If the contractor caused the leak, then in my opinion he is responsible for the repair.

The owner should send his best techinican to figure out what is going on. Where in the house is the furnace located? Was any duct modification (other than the change in the return) done during the installation. Was the duct work inspected before and after the installation?

    Bookmark   June 30, 2012 at 4:25PM
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The furnace is in the basement no duct work other than the new vent for the high efficent furnace. The owner is here now he says a new coil is about 800. I did say I would split cost I don't want to but were burning down out here it is hot. I just want it fixed.
I don't know what I should do.

    Bookmark   June 30, 2012 at 4:53PM
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Well he is going to put a new coil in I did say I would split cost he said he was going to put a size larger coil in.If he makes me split cost what should I expect? There is a leak there wasn't one before. when he went and checked the gage out side it was down to 30 when it was 40 yesterday. It is leaking no question. I wish I hadn't offered to pay half I think this happened during install.
Thanks for any input

    Bookmark   June 30, 2012 at 5:18PM
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