howdy i got new ac installed and the darn thing works for a while then shuts off and starts getting warm (the room air) now what i have noticed is the return line the one that goes
back to the fans is cold (nomaly its hot)
ive had the ac guy out here but hes no help(idiot) he tells me turn it down to 78 . ok i put it at 78 still no fix. now i can shut it off for about 30 seconds and restart and all is fine for a few hours 5 or 6 . and it starts over again . this unit is brand new.
outside temps are 102 + i like inside 74sh.
i tack the cover off and tap on the valve at the hot line and it will start getting hot and the air coming out is colder. what is causing this or how do i permenlently fix it. any ideas would be of help. im no ac man but if i had some info about these im sure i can fix it.
help its getting hot.
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07-24-05, 10:23 PM
bedstor

quote:
i tack the cover off and tap on the valve at the hot line and it will start getting hot and the air coming out is colder.


The clue to your prob is here I know a bit about central heating Nothing about A/C but it suggests an airlock in the area of this valve (is there any way of bleeding the system?)

07-24-05, 10:32 PM
dodgecity
no i dont have any gauges or anything like that.
it just shut down again this time i turned the thing off then turned only the fan on wait a couple of seconds and then turn the ac on and bingo it works again very weird . now i dont know if its electrical or macanical.
i wish i knew more about this stuff.im pretty sure there,s enough gas in the thing but there,s something thats just not quite right.
i hate it when i dont know whats going on.
any way i dont have it figgered out yet.

( i wonder if they wired the thermostat right)
i beleive that when it gets too cold in the line's it's suposed to shut the compreser off and then start it back up when it get's back to normal. i think

07-24-05, 11:12 PM
bedstor
Are there any clocks or lights which indicate low pressure?
On my combi boiler there are indicator lights for low pressure and how the season demand
there is a clock which is never set for on/ off times , and there is a guage marked in Bars
(air pressure) to tell me how the system is pressurised if its not wotking for several week it falls to zero and I might have to manually bleed the system so I open the stopcock valve on the cold waterpipe into the unit and give it 5 to 10 minutes for the air to bleed out often producing a fountain out of the overflow
meanwhile the Pressure rises to about 2 bar (30 psi) the whole system starts creaking once the system is almost air free Big Grin I shut the valve turn on the boiler and the pressure increases again to about 3 bar(40 psi) this should last for several weeks falls back to 2 bar (there is a slow airlock in my setup somewhere Roll Eyes)
Ask the engineer or read the Handbook where the bleed points are.. He should have shown you where they are. Also the water cut off tap I imagine they are all within inches of each other?

07-25-05, 12:02 PM
Walks On Water
Now you're playing my ball court. As a 30 year veteran in the air conditioning business, by your symptoms there is something wrong with the installation. The company that installed it BETTER check it out and correct it. I only assume you have a warranty with it.

Call the company that installed it and ask for the Service Manager. Tell him that if they don't get it fixed, you will call another company and he will be responsible for the bill as you have tried to get him to fix your problem.

If this was installed by "A Friend" you may have a problem right there. The untrained person may have installed the wrong unit for your system. The 3 major components must be match for the unit to work right. The furnace, evaporator coil and the outside condensing unit.

Now for your problem. It is very hard to diagnose a problem with out "Laying Of The Hands".

Please, please, please don't bleed any lines. Don't try to fix it your self as this can void any and all warranties.

Is this a heatpump? What make are we taking about?

Was this A/C just added to your furnace or did you get a new furnace with it.

I want you to check some points for me then let my know. These are all assuming that this is "Whole House" air.

1) While the unit is running, is the small un-insulated line warm or hot to the touch?

2) Is the fan on the outside unit running?

3) Just before the units shuts off, does the large, insulated copper line have any frost on it where it comes out of the furnace or is it just sweating wet? That line should be no colder then 35 degrees.

These are just 3 of the quick checks I do when I first come on the job.

07-25-05, 09:10 PM
dodgecity
question # 1 no when it stops working that line is very cold.

question #2yes the fan is running on the out side
question #3 no its not frozon just sweaty.

now it seems to fix its self when i either tap on the poa valve or turn the ac pump off then witch also turns the inside fan off or at least when it get done. now i can turn just the fan on then turn on the ac pump and wala it works for three or four hours.
and yes the so called pros replaced everything
the inside and the outside. but there pretty much idiots. they installed the condensation pipe right over the filter so you cant change the filter. hes suposed to come back out again and check it out . but im betting he cant fix it
cause i was having the same problem with the other one (well almost the same problem it would not get below 78 79 degrees.
oh its not a heat pump i had one of those in washington it worked great. it was installed by the ac people and its a carrier unit no furnice

07-26-05, 05:14 PM
emkayess
I can feel your pain. My AC has been acting weird since I turned it on in June. At first it would not shut off - had to manually turn it on or off.
Now it works - sort of - except the temp is off. I have to set it for 80° to get a 74-76° on a separate thermometer. The temp shown on the thermostat shows no relation to actual temp.
Don't know if I need a new thermostat or something else. Unfortunately I don't understand things like heatpump etc. My unit is 5+ years old and was added to an existing furnace ... by a shoemaker(&%#). I'm getting to old to do without AC- Chicago is having a heat wave right now. Good luck on fixing your AC dogecity.

07-26-05, 07:25 PM
dodgecity
i think that by what your saying is the thermostat is bad . sounds like

07-26-05, 09:52 PM
dodgecity
well an update the ac man is coming in to put an boost kit(what ever that is) says it will fix it. i think the poa valve is bad. but we'll see Confused

07-27-05, 07:30 AM
Walks On Water
Sorry I am late getting back. Been up to my ---- in "to hot" calls with this heat wave in the area.

I would like to know what a "Booster Kit" is and what does it do.

I am still not sure what the problem is with your system. As I said, it is hard with out being there. Don't pay for that "Booster Kit". Sounds like a come on to me.

3 tons of A/C is 36,000 btu of cooling and nothing you can add will change that.

Approximately 1 horse power = 1 ton of cooling = 12,000 btu (btu = British Thermal Unit)

It still sounds like a miss-match somewhere along the line.

07-27-05, 08:59 AM
Fritzzs
I would send a registered letter to the installing company giving them so many work days to fix the problem, or you will hire someone else to fix it and then take them to small claims court to recoup your expensives..

And for crying out loud, DO NOT pay for that booster kit... If it needs it now, then it needed it in the beginning....

BTW, how many square feet of house are you AC'ing ????

07-27-05, 08:09 PM
dodgecity
i dont know what it is either but i told him the samething i always tell him. get it fixed and dont charge me a dime for it because its your problem now. you put it in you make it work. he's getting frustated at me but now ive made contact with his boss. i think this guy really dosent know what the heck he's doing.
i mean if i did ac work for 5 years let alone 30
i sure would know how to make it work one way or the other. it's cooler now but not much.
his boss say's maybe the thermostat is the problem. (thats the one thing they did not change) and maybe its bad i dunno. ill keep ya posted if i find out the real problem.
(i hate dealing with boso's) Big Grin

it about 1000 sq feet.kinda small

07-28-05, 05:39 AM
Fritzzs

quote:
it about 1000 sq feet.kinda small


================================================
Well, theres your problem... You were sold way too big of a unit.....
Go call another AC company , and tell them how many sq feet you will be cooling and how much...
Sumtin tells me you have a fish hook in your lip.. Eek

07-28-05, 06:42 AM
Walks On Water
I think I have to agree with Fritzzs, but I don't know what size A/C you bought. For instance, a 24,000 btu unit would be a little on the large size for the squares you indicate. This is of course in my climate. And now they want to put a booster kit on it. I am really puzzled

It is better to install a little smaller then needed. If over sized, the unit would turn off on temperature when reached while the air would still be full of humidity. A unit that is just a little smaller in size for the space would run longer to reach set point. This would allow it time to pull out more humidity. A dry space at 80 degrees would feel as cool as a space that was 70 degress and humid.

One of the tricks we use when we want to dry the air faster is over size the evaporator a little. This give us more surface area for the water to condense on with out cooling the ar to fast. This is use in areas where we would expect a higher normal humidity.

For instance, 26,000 btu condensing unit with a 30,000 btu evaporator. There is a lot of engineering in this so don't try to figure it yourself.

For a walk in meat cooler (cooling is cooling no matter what the product is) we would over size the unit to cool quickly so we would not dry out the meat.

PS
Every new unit I sell I include a new theromstat. Cheap insurance. Besides, our company logo and phone no. is on it.

07-28-05, 10:20 AM
Fritzzs
I don't know where the ell my head has been, but next door to my store is an AC distributor...
Heres what I found out from the experts...
Rule of thumb:
1000 sq. ft house should have an 18,000 btu Ac unit...
1 ton unit = 12,000 btu's
You said they installed a 3 ton Unit ??
So, in other words , what you need is a Ton and a half unit....
You have twice the size of unit that is needed.. That means it will cool so fast that it will shut down before the humidity is removed...
It is best to be slightly under-sized than over...
I think you need to have a pow-wow with someone...

07-28-05, 10:59 AM
Walks On Water
Fritzzs,

I said 3 tons as an example, he never told us what size he had installed.

And yes, about 18,000 btu is all he should need unless the are other extenuating circumstances.

07-28-05, 03:12 PM
emkayess
Hi, could I butt in again. How much humidity should there be in the room air. The thermometer I am using to check the AC also has a humidity meter(?) and it shows about 30%. I am finding this discussion very informative. Because the (%#@) shoemaker who installed my unit did say it was larger than we needed. Maybe that's my problem. Chicago has killer heat only every 4-5 years - so I didn't realize there was a problem.
TIA MKS

07-28-05, 04:11 PM
Fritzzs
As I said earlier, it is best to slightly UNDERSIZE than oversize....

07-28-05, 08:43 PM
dodgecity
i dunno what size the unit is he said its the right one for here. so im going by his word. im still waiting on the thermostat. and what ever he did up there on the roof it's working better now. can main tain 78 degree's now. it's 106 outside. so we'll see.
think maybe the booster thing was maybe to help get the R134 stuff down the the fins ? it's about 25ft of line's the run down to the unit
. i dunno he's supposed to come out tomarrow with the boss

07-29-05, 09:32 PM
dodgecity
well an update it works pretty good now it can maintain 77 all day he changed the termostat.
and what ever he did it works now. i need some insulation so i can get it down to the 60's.
need some new windows too. he could not show me this miricle thing but i did not get charged for it so im happy. all i want is cool.
Big Grin Big Grin

08-03-05, 07:33 PM
dodgecity
ac on then off
yahooo 75 today outside is 102

This message has been edited. Last edited by: DorianGreyed,