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R.G., HVAC Technician
Category: HVAC
Satisfied Customers: 319
Experience:  20 yrs. experience as HVAC technician, state certified contractor.
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My air conditioner is new and was just installed. It is a

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My air conditioner is new and was just installed. It is a Bryant and today the installer came to tweak a few things and install some dampers to regulate air flow and to install the new thermostat which was not in on the install day. We set it to 72 and all day long it has been running and saying it is 75. The only way I could get it to go off was to change the set point to 75. It went off for a few minutes and now is back on again. It says it is 75 and the set point is 75 so it should go off I would think. Any ideas?

R G : Hi, I am R. G., sorry you're having trouble today, I will do my best to assist you in resolving you're issue.
R G : Thermostat should have a differential usually 1* meaning if set on 75 it will cut off when reaches 74 and back on when it reaches 76.
R G : Sounds like there is an issue with unit if it's not getting temp below 72 or it is undersized.
R G : Is this the first day you have had it running?

no it was running for over a week with my old thermostat and got down to as low as I wanted it.


It just shut off but don't know why I could not get it to go below 75


Are you still there?

R G : With unit running you can take a thermometer and check air temp coming out of vents, it should be approx. 20* colder than room temp.

I don't believe I have a thermometer handy but I can try to see about doing this tomorrow.

R G : Replacing thermostat shouldn't have an effect on amount of cooling, it just turns it on or off depending on temp, unless he wired it wrong and a heat strip is coming on during cool making unit work against itself. I have seen this done before
R G : Do you know what else he did today besides replace the thermostat?

I can call them tomorrow although I don't know if I can get them. I do have his cell number so I can try that but I am concerned about turning it back to 72 and having it run continuously.

R G : Does it feel like temp is about 75 in house or is temp getting colder and thermostat still reading 75?

Today he had to put in something related to the furnace since it was a full HVAC system and he installed some dampers to try to get the air flow more even and it seemed to help. I just realized late this evening the thing had not shut off since he left around 11 this morning.


It felt like it was getting colder but thermostat still reading 75

R G : Do you have a thermometer outside or a meat thermometer in kitchen maybe you could use to check and see if thermostat is reading correctly ?

I was looking for a thermometer but the only one I have is the old fashioned kind to take temps with and I don't think it goes that low.


The unit just came on again. Seems to regulate at 75 but not at 72


Come to think of it, it has not said anything other than 75 as the temp all day

R G : Sounds like temp just isn't getting low enough, when you can get a thermometer and check temp to verify thermostat is reading correctly and then check temp coming from vents if it's not approx. 20* colder than return air going in air conditioner there is a problem with unit
R G : Okay what is make and model of thermostat?

When you say it should be 20 degrees colder than return air, does that mean 20 degrees colder than the thermostat is set at?


The thermostat is a Braeburn Premier series model 3000

R G : No 20* colder than the actual temp of air in house that is circulating through AC to be cooled. Just room temp near return filter

Okay, I can check this tomorrow when I get access to a thermometer. Do you have any info on the thermostat?

R G : One moment pulling up manual now. Did installer leave you a manual there on thermostat?

Yes I have it right here. Fun reading!

R G : Okay I'm looking at a manual now was gonna send you a link if you didn't have one
R G : The thermostat shouldn't cause unit to not cool properly as long as it is turning unit on, but if room temp is dropping and thermostat Temp doesn't you may have a faulty thermostat
R G : Sounds like unit just isn't cooling properly
R G : One thing to try if you haven't already

What did you want me to try?

R G : Was going to get you to make sure thermostat wasn't still in set up mode but looking back if you were able to adjust temp it can't still be in set up

Yes and while he was here, he turned on the heat and made sure it worked and then turned on the AC and checked it with the thermostat. Then we left it on 72 because he knows I like it fairly cold

R G : I think you have a problem with unit not cooling properly or possibly a problem with duct work in attic or under house not sealed and sucking in hot air or loosing cold air
R G : If he was working with duct today it is possible he forgot and left something loose or open

It was cooling fine with the old thermostat, in fact it was too much air in some rooms thus the reason for the dampers. What I did notice later tonight was that some of the vents we regulated with the dampers seem to be going stronger than we had them with the dampers. It is too much air and was less when he left but now it seems like it is back to the way it was before the dampers. Can the dampers slip or move or get out of place?


He also did something with the venting of the unit out the roof but I think that is for the furnace.

R G : Yes the vent would be for the furnace. Yes depending on dampers he installed it is possible for them to move if not secured. Also if you cut airflow down too much on a unit it will cause it to freeze up which will cause airflow to get even lower due to coil being blocked with ice. Have you noticed any ice on copper line going to outside unit?

Do you mean the line that would go to the compressor outside? I can check but would likely melt pretty quickly. If this is where you mean I can check for ice.

R G : Yes the AC coil at furnace would ice up first if this is happening but would eventually ice up copper line all the way back to compressor outside. But once it cut off it would melt off

No evidence of ice outside on the line--just some grasshoppers

R G : Okay the grass hoppers shouldn't hurt anything :)
R G : Sorry but I can't come up with a remedy other than get the installer to come back and see why unit isn't cooling properly. Would need a thermometer and most likely refrigerant gauges to test and locate problem

Okay. Good night.

R G : Please reconsider the rating
R.G. and other HVAC Specialists are ready to help you
Thank you for changing rating, let me know if I can give any further information once you get a thermometer and verify if thermostat is reading correct temp.