new system..new digital thermostat. Ac is cycling too much


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Old 06-30-10, 12:32 PM
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new system..new digital thermostat. Ac is cycling too much

The new digital thermostat, combined with the new system I just got, is making the system cycle too often. My tv sits very close to the thermostat. It gives off heat. There is also a ac vent approx 8 ft from and blowing towards the thermostat. I think this happens...the system kicks on and cools down quickly due to vent closeby, causing it to shut off. Then, while off, the extra heat from the tv warms the sensor up too fast, kicking the ac on again. I guess my old manual thermostat was not very accurate combined with the system being older and taking longer to cool down. Anyway... Ive read about honeywells not being able to change the cycle per hour for ac...too bad.. Is there a thermostat that has a remote sensor that I can install in a more consistent place in the house? Is there a thermostat that can be set to 75 and 78, so when it gets to 75, it doesnt come on until it reaches 78 in the home? What are my options? Am I going to have to move the thermostat? The tv cannot move.. seems like there is always something.. thanks guys
 
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Old 06-30-10, 01:17 PM
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The only thing new is the thermostat?
 
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Old 06-30-10, 01:41 PM
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no.. I had new coils/furnace installed today. The compressor was installed last year. I went ahead and installed a new honeywell PRO TH4000 series. I have it set to 77f. It doesnt even get to 78 before it kicks the unit on. Its almost like its too sensitive. Again, the older manual thermostat was probably less sensitive, combined with the new unit cooling quicker and the tv situation. I just wanted to know if the sensitivity or temp difference can be changed on this thermostat or other thermostats? I really think its the location, combined with tmstat sensitivity. I timed it... its running for 8 minutes, and off for 8 minutes. Seems like alot .. what is ideal for a 90deg, cloudy, 54% hum?

I think its all thermostat and need suggestions....maybe I will
thanks
 
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Old 06-30-10, 04:28 PM
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If you have it set at 77 and you had your wish of it going on at 79 (or higher) I think you would be most uncomfortable, and 75/78 likewise. I don't know why you don't suspect the new coil. If its putting out colder air it might be short cycling cause it reached the set temp quicker. Being new it doesn't have crud on it too. Does it seem to blow more and/or colder air than the previous setup? Give us sq footage and tonnage on condenser and coil and location and we'll have more clues. You could buy a directional vent if you want to try that, or switch with another one.
 
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Old 06-30-10, 05:45 PM
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1450 sqft, 3ton 13 sr Goodman compressor and coil. Gas furnace/coil installed in attic. Yes, I do think its colder and slightly increased volume. I was thinking earlier about a different vent and closing that vent some. I just thought the thermostat has alot to do with it since it kicks on and off with just a less than half a degrees difference. I thought the simple answer would be to change the temp sensitivity, but found out you cant with this tmstat. The heat from tv doesn't help. I just want to find a way to prevent the on/off every 8 minutes. That number adds up quickly and any recommendation on how to achieve this will be greatly appreciated. So let me know if im turning a easy fix into something complicated. thanks
 
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Old 06-30-10, 06:03 PM
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Try leaving the TV off and see what happens.
 
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Old 06-30-10, 10:30 PM
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Just wondering...

Where is the return vent located? In hallway? Thermostat should be close to return air in hallway...not in living room or den.
Just a thought.
 
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Old 07-01-10, 05:01 AM
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Originally Posted by drivebytrucker
My tv sits very close to the thermostat. It gives off heat.
T-stat should not be near heat producing items. As last poster stated, should be in the hall way and/or near a return.

Ive read about honeywells not being able to change the cycle per hour for ac...too bad..
Only on most retail model. Yours is a pro model, so function #9. I set most of them at 2.

Is there a thermostat that has a remote sensor that I can install in a more consistent place in the house?
Yes, they can be spendy. Be cheaper to move the t-stat.

Is there a thermostat that can be set to 75 and 78, so when it gets to 75,
There is, but the comfort will not be there. Going to have those "It's getting warm, when is it going to turn on?" then "It's getting cold, when is it going to turn off?" moments.

1450 sqft, 3ton 13 sr Goodman compressor and coil. Gas furnace/
Where are you out of? To me that seems oversized!
 
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Old 07-01-10, 09:21 AM
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Im in the DFW area. So summers are usually 100d + or - 5 daily for 2 to 3 months out of year. Been reading...my tstat has .5 swing? is swing the correct word? My old mechanical probably had much wider tolerance. I replaced a 3 ton with a 3 ton. My old system never acted like this so im thinking its the thermostat. Is there a compatible thermostat that allows you to change the swing? Some will let you .5, 1, 1.5 and 2 degree.
I believe this would be a huge help. I have a Goodman GME8 furnass. Do you know if the ac blower has multiple speeds? Seems like it could stand to come down a speed. return in hallway ceiling. Thanks for all feedback guys. Amazing how much you can learn when you have to. This is a great forum also.
Jay, read that you can change the heat CPH, but not AC. Im I wrong?? thnx
 
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Old 07-01-10, 11:05 AM
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Most T-stat has 1 degree swing, not sure why you got a 0.5 one. but many of them can be adjusted. read the user's guide first before you buy another one. (talk to Honeywell to see if your T-stat can be adjusted)
 
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Old 07-01-10, 11:36 AM
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Originally Posted by drivebytrucker
Im in the DFW area. So summers are usually 100d + or - 5 daily for 2 to 3 months out of year.
On your old A/C when it got say 105˚, did it run steady non stop?


Been reading...my tstat has .5 swing? is swing the correct word?
Yes in a way. The t-sat don't show the 78.5˚, just 78˚.

Is there a compatible thermostat that allows you to change the swing? Some will let you .5, 1, 1.5 and 2 degree.
Yes. I used have one of those, and hated it.. The comfort was not there.


I believe this would be a huge help. I have a Goodman GME8 furnace
Need the full model #.
Do you know if the ac blower has multiple speeds?
Yes, but need full model # on the furnace.
return in hallway ceiling.
Move the t-stat to the hallway.

Jay, read that you can change the heat CPH, but not AC. Im I wrong?? thnx
You can change the CPH in cooling. Cooling never been an issue, so that's why I didn't post anything on cooling side. Heating seems to be the big complant of the on and off cycle.

In my last post, set up #9 set to 2 or 1.
 
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Old 07-01-10, 11:45 AM
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Originally Posted by clocert
Most T-stat has 1 degree swing, not sure why you got a 0.5 one. but many of them can be adjusted. read the user's guide first before you buy another one. (talk to Honeywell to see if your T-stat can be adjusted)
Honeywell Digital don't do the swing.
 
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Old 07-01-10, 01:11 PM
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Swing is not a right word. What he want is a thermostat with adjustable 'hysteresis' ..
 
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Old 07-02-10, 07:02 AM
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coil is goodman CHPF3636B6
compressor is a GSC130361
furnace/blower gme8 I thought I brought the number with me today, but missed it somehow. If wife threw it away... I will be vewy mad.

Im going to have to call out a real expert if my tech doesnt understand. Hes going to come out cand discuss. The coils have a expansion valve instead of just a orifice(if this is true?) and can prevent freeze up. If I can turn down the motor one speed, I may be screwed. I have to check the humidity inside(can tech do that)... The humidity is important since I have sarcoid (a lung disorder etc.. etc..
Im really starting to worry now. If I could move my tstat, turn down blower motor, or do anything to get the thing running at longer cycles, it may help. I wish I knew a expert in my Arlington Tx area that could take a look at it. Any info would be great. I research everything to death but this, since it had to be replaced and we didnt increase the size, I thought everything was good. It cools really cold and blows harder than last system.
 
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Old 07-02-10, 02:56 PM
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The model # is on the furnace itself, so let me know what the results are.
 
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Old 07-03-10, 12:02 AM
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I'm in San Antonio. I think your 3 ton will be good. Maybe a little long in run time on 100plus days, but that's the way theyre spec'd.
 
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Old 07-03-10, 12:36 PM
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coil is goodman CHPF3636B6
compressor is a GSC130361
furnace gme80703bx ... The tech left the speed settings on the blower motor at default (he was recommended and I used him to replace the compressor last year.
He is going to lower the motor speed. Ive heard this could cause coils to freeze, so any input there would help tremendously. My options now are, unless otherwise specified are....
-I closed the vent nearest the tstat, not much help
-lower motor speed.
-will try a tstat where I can set .5, 1, 2 (can someone recommend one that allows these settings)
- and also need to move to hall, but need to take temp measurements first.
-tear out system and start over
-also by a dehumidifier for extra humid days

Another thing is that...on the days where its only 85f and 95% humidity (like today) my old system would still run slower and not so cold, so the new system is freeze out, freeze fast

finally, the system seems to shot down for 5 seconds then comes back on without the tstat clicking. weird
 
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Old 07-03-10, 01:06 PM
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The manual is not clear, but If the cooling speed for the blower is set to T5, you can drop it down to T4.
 
 

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