A/C won't go below 80*

[mbarizona]

Newb here...got a question. I am using the search function, but it is taking a while to go through those posts.

I have a Goodman 12 seer, 5 ton unit in a 2100 sq ft house with 9 ft. ceilings.

The house was built in 2000, so the unit is 8 years old. Being in Arizona, temps are in the 110's during the summer. For the last 7 summers, it has been fine. This year, the inside temp will not go below 80*. I can set the temp at 81, it will kick on at 82 - bring it down to 80 and kick off just fine. If I set it at 80, it will kick on at 81 and continually run because it won't go below 80.

I have tried a couple different thermostats, new filters and have had 3 different service companies out here to look at it. All 3 have said that the unit is working at maximum efficiency and there is nothing wrong with it.

There must be something different as the last 7 years was not an issue cooling the house to 77*.

Any thoughts??

Thanks,

Mike

[iraqveteran]

get another opinion.

I would be willing to bet that you need to have it serviced.....Properly.

[mbarizona]

get another opinion.

I would be willing to bet that you need to have it serviced.....Properly.

Can you explain what properly is? Is there a certain term I should use when requesting service?

All have stated that a general checkup would be sufficient.

All three have done the following:

Checked the blower motor for dust/build-up.
Checked the coils for dust/build-up.
Measured pressure at the compressor.
Checked freon(?) levels.
Inspected return pressure.

I am sure I am missing something, but where?

Thanks for the reply.

[comfortdoc]

Can you explain what properly is? Is there a certain term I should use when requesting service?

All have stated that a general checkup would be sufficient.

All three have done the following:

Checked the blower motor for dust/build-up.
Checked the coils for dust/build-up.
Measured pressure at the compressor.
Checked freon(?) levels.
Inspected return pressure.

I am sure I am missing something, but where?

Thanks for the reply.

You are missing the part where they actually clean the coils etc, not just check them. Given your symptoms I might also look for duct leaks.

Don't call for pre-season "tune-up" specials. If the system truly cooled the house below 80* at 110* outside in the past you need to request a service call and understand it might take a couple hours to properly diagnose the issue.

[beenthere]

Tell them you want it cleaned and serviced.

[gary_g]

Check ductwork for leaks, especially if they run in a hot attic.

Measure superheat and subcooling to determine if system is charged properly.

[dj3901783]

I live in Phoenix, AZ so if you live you can e-mail me with the contractors you've had at your house and I can tell you if that's the problem. There's a lot of very poor residential companies in phoenix... I've gone behind them a lot.. actually an hour ago a company told the customer they cant fix his leak, took me 2 min. to braze or "weld" it shut again, hard to say what's really going on. I've seen companies not even inspect the air handler/furnace and tell them they need a new indoor coil... sooo ????

[dj3901783]

how do I put my e-mail up in my public profile?

[dash]

Turn off all exhaust fans .clothes dryer,etc.,then to find large duct leaks,open the door between the home and garage just a crack,with the system on ,if air moves in or out you have large duct leaks.

Air moving in indicates suppy air leaks,air moving out indicates return duct leaks.A candle is a good tool here,significant leakage can blow it out.

Unfortunately if the supply and return lweaks are equal,no air will move in or out.

So it also follows that,if the supply leaked 50 cfms and the return 100 cfms,the door would only indicate 50 cfms of return lakage,not that all 50 cfms would be following the cracked door.

[beenthere]

]dj3901783999 at hotmail dot com

No email addys or email links allowed in post. Edit yours out.

[mbarizona]

Thanks for all of the replys and suggestions.

[johndoe74]

started a new thread...

[tinknocker service tech]

I have a similar problem, I live in AZ and one of my Goodman 3.5 ton SEER 12 units (only 2-year-old) is having trouble cooling the rooms below 80F in daytime after running for at least 3 hours straight (outside temp 100 to 110F). The differences between ambient temp and cool air coming out of the vent vary from 11F to 18F. My attic has R30 insulation.

When the tech came, here are some measurements he took:

Sub cool: 11F / 10F
Superheat: 5F / 5F
Low side PSI: 75 / 77
High Side PSI: 280 / 260
Compressor: 22.1 - 18.3
Condenser: 1.6 -1.1

He told me those numbers look fine, and all he did is changing the piston from size 74 to 78 (according to him this will increase freon flow), and 'flush' the system.

Anyway, those didn't help at all, and now I have to call them back and do more diagnostics. What else can I ask them to look into?

first not meaning to be rude but start your own tread so any info is for your problem only
thanks


now to the OP
call and ask for a service call and not a pm. Let them know you want you coils cleaned mainly the outside condenser coil. With the sand and or pollen it doesnt take muck the plug this coil and you will loose cooling.

you want readings pressure and temp. Super heat and subcooling not just it is running fine that doesnt cut it.

you want the system checked for leaks in ducts


this may cost more but not as much as all the maintence calls have that havent fixed your problem

if it cooled your house last year at 110 then it should do it this year
if it didnt then no matter it wont again

[mbarizona]

Check run capacitor for condenser fan, if it is domed on top or swollen that may be the problem. Went on a call 3 ton Goodman condenser fan was turning backwards, drawing air in through top, cooled ok until the heat of the day. Capacitor was bad unit ran for 2 years like that before the guy would ask for help.

The condenser fan is outside correct? If I put my hand over the top of the unit, air is being pushed out. Would I not feel air if it was going backwards? I did look at the capacitor, it 'looked' fine. I did notice that the contact panel had some black residue on it.

[mbarizona]

Should water come out of the drain pipe that goes from the attic unit? I have noticed that it is dry and haven't seen water in a while.

[beenthere]

Call a service company. The longer you put it off, the greater the possibility that it could develope mor trouble and cost you more to get it fixed.

[mbarizona]

I will be calling another company...this will be the 4th company.

So, gathering information from the posts, here is what I should tell them:

Check ductwork for leaks (CFM test on all ducts?)
Measure superheat and subcooling
coils cleaned
check the system for leaks in ducts


Anything else??

Thanks again for any and all suggestions!

Mike

[mbarizona]

Getting ready to call a company out tomorrow...are these the items I want checked?

Check ductwork for leaks (CFM test on all ducts?)
Measure superheat and subcooling
coils cleaned
check the system for leaks in ducts


Anything else?

[beenthere]

You may have to make several calls until you find a company thay can check CFM.

[mbarizona]

......started new thread to ask.