Whirlpool straigt cool unit10 seer

[nbulls34]

Last month I when on a service call to check a new unit thats not even a year old. Cust complaint was that the unit would cool fine at times and then I would stop cooling that the temp started to raise quickly. I notice that the temp on the tstat was 78 and the cust had id to 72. That was the first thing that caught my attention, so I put my thermometer on top of the tstat and sure enoght it was 78 degress. Then I put the thermometer closer to the return and it was 72. By the way I forgat to mention that the tstat was not close to the return it was on the middle of the house and there was a hot spot there. So I move the tstat to the wall where the return grill its at and that cure the problem for a little wile. few days later cust calls me back and Saids to me that the unit is doing the same thing. By that time Im scrashing my head the subcooling its fine superheat its fine what the heak can be causing this problem? Anyways I said to my self well it got to be tstat so I started to mess around with it an I discover that the unit was short cycling. So I said ha I got it Im going to check the settings on the tstat the installers forgot to set the compressor lock out on the tstat. I put it on and it work fine for a few days again. Cust. calls me back by now Im getting little mad at the situation so I put a tstat on the wall to see if this is the cause of the problem now im begining to fell like a parts changer tech. So I tell the custumer ok lets try this new tstat and if this doesnt change anything I will replace the compressor by the way I had allready install a new hard start kit on it to help it on start up. But guess what? The cust. call again. Finally my boss said ok we have try everthing change the compressor. So I did. A month later cust calls again with the same problem. The only thing left to replace is the txv. there is nothing else I dont know what the hell I was thinking by replacing the compressor first. I guess I over look a the situation. If anybody has any other sugestion please let me know Im going to go nuts. thank you

[dash]

Where are the return and supply grille located,floor ceiling,wall??

[iheatncoolinnc]

I recommend never telling the customer if that does not fix I will do ???. it leaves doubt in their mind. I have made an adjustment on ??? and lets see how this does is better. Is the equipment running when the temperature starts rising? Could the heat be coming on with the air conditioner? Contactor not making properly everytime? Low voltage to the unit? Only does on hottest days and unit undersized?

[nbulls34]

Im not quite sure what you mean. I dont know if I sould take your coment as and insult or a joke. But if you must know I got 4 years expiriece on the field allready and I think Ive seen quite a bit. IM Nate cetified and got my training from a technical school. So I maybe overlooked at the situation that is why Im asking for advice But I didnt know you were going to come out very strong By posting that coment from Wallace Lee,former ACCA Chairman. The return is on the wall leading to the garage. The contactor makes ok and doesnt lose any power.The unit was replace I guess to what they had before.Static press is ok was .48 and the subcoling is 10 degress.

[Edited by nbulls34 on 08-18-2006 at 10:28 PM]

[iheatncoolinnc]

Sorry about the original comment.
You stated originally that the unit was short cycling and you changed thermostat. Is the unit still short cycling even though the thermostat is calling? We have what I call load control. This is put on by the utility Company to shed air conditioners when temperatures are higher and gives the customers a rebate. These can cut off units for up to 7.5 minutes every 1/2 hour which amounts to a lot of capacity of an air conditioner. They are generally mounted next to the disconnect and the low voltage wire goes thru them so they can cut it off.
The only reason I asked about contactor is we had one that worked most of the time. Found contator problem with power off to outside unit and connected and disconnected low voltage to contactor about a dozen times. It stuck one time and did not pull down straight.

[nbulls34]

So this load control that you are talking about is works like a time delay. Perhaps I should put an adjustable time delay and set it to 7 min. instead of th 5min delay on the tstat. Maybe the house doesnt hold temp very good due to poor insulation. And the unit is calling too soon not giving enought time to equalize.

[iheatncoolinnc]

They send signals across the power lines and open a relay in the load control that breaks the low voltage to the outside unit. The unit then stays off for 7.5 minutes. You would know if you had an extra box or if the low voltage did not go straight to the outside unit.
A five minute delay is plenty. I would rather have it thru the thermostat.
You can check equalization very easily. With gauges on unit, turn on system, let run for over five minutes, cut-off thermostat and turn thermostat back on. Five minuted delay will keep unit off. Stand by outside unit and see if equalized when restarts.

[Edited by iheatncoolinnc on 08-18-2006 at 10:54 PM]

[nbulls34]

Ive done that allready and the tstat waits the 5 min. So I think Im ok on that end.I think the txv is whats causing this problem. Hell I allready replace the compressor And that didnt do the trick. What do we have left? Txv.

[iheatncoolinnc]

You have the static pressure, but do you know the CFM of the system. Also, what is the temperature split accross the cooling coil? Does the indoor fan and outdoor unit run nonstop when the temperature is above the setpoint of the thermostat?

[icyflame]

From the info that you gave...what was your justfication for changing out a compressor on a less than one year old system??? You would really hack out a compressor before you would check out the TXV? You went from the tstat to the compressor knowing that the superheat and subcooling was fine...and your Boss concured?? AND You're NATE certified!!!???

[nbulls34]

So nate certified techs dont make mistakes? Its that what your trying to tell me? So if superheat and subcooling was there means that the txv was doing its job right? What would you do then? I already put a hard start kit on it so if it was having a hard time starting I have that part covered. I ran out of obtions. I made the wrong decition I shoulded change the txv first instead of the compressor. Rest to sure that I wont make that mistake again. You make it sound like you never made wrong decitions.

[Edited by nbulls34 on 08-19-2006 at 02:28 AM]

[fl1]

78° at the stat,72 at the return.


Poor air flow,stratification,is the cause.Return is low,cold air is settking low,supply grilles don't have enough velocity to mix the air in the room.Where are they located??What type of grille??



Where was the static measured,what was the return and supply static.

[ARPA]

Sorry,

But nbulls34, you need to read the http://WWW.clicksmilies.Com/s0105/sauer/angry-smiley-014.gifForum Rules (http://hvac-talk.Com/vbb/showthread.php?threadid=1241).
Until then, and you register as a pro (click on the contact us tab at the bottom of the page) this thread is closed.
When you have registered correctly, I will open this thread back up and move it into the proper forum.