Compressor won't shut off

[bdr]

I am having some trouble with my CAC on my second story. We have two separate systems; one up, and one downstairs.

First: My system seems to run more than expexted, and more than the system downstairs, even at night. I beleive part of my problem is the thermostat location (upstairs hall, near return, near stairs, no ducts to hallway). For instance, if I set my thermostat to 74, the 4 bedroom will all reach about 71 degress before the system shuts down. This occurs even with the bedroom doors wide-open. I am guessing this happens because of the return sucking the warm-air from downstairs right past the thermostat? Should I move the thermostat?

Second: I have also noticed that even at times when the thermostat's room temperature equals that of the set temperature the system still runs. This eventually causes the thermostat to read a room temperature below that of the set temperature. For example: T-stat set @ 75, reads a room temp of 74 (in hallway) and the bedroooms are about 71 (seperate therometer). When this occurs the fan in the outside condensor unit is running. Any thoughts?

I am puzzled..Thanks for your help!

[tinknocker service tech]

have someone caome out and check the t stat
i would have it moved to the master bedroom also

[bdr]

also....

Not sure if this is normal either:

I noticed a relatively large amount of water flowing from the outdoor compressor that seems to continuously run.

[jolleyman]

Your thermostat should be located near your return air register. If you dont already have one, you may want to invest in a digital thermostat, they are more acurate.
If you have condensation building up all over your compressor, the system is most likely overcharged. That's not good. The line should sweat back TO the compressor-the only way to get an acurate charge is to charge it by superheat.

[bdr]

I am using a LUX programmable thermostat. The entire CAC system is new, firt cooling season.

[travisfl]

Originally posted by bdr
I am using a LUX programmable thermostat.

This is a very cheap thermostat -- you are probably getting what you paid for. Consider a professionally installed Honeywell VisionPro with one more more remote sensors. The remote sensors can average the temperature across multiple rooms and control your system more accurately.

[Edited by travisfl on 06-28-2005 at 09:00 AM]

[smokin68]

Sounds like it needs to be balanced better,along with what others said. putting in a Lux stat is like putting an eight track player in your new Mercedes.

[tpa-fl]

Lux Sux... seriously, get that piece of junk out of there before it causes serious damage.

see this thread:
http://hvac-talk.com/vbb/showthread.php?threadid=76045

[bdr]

excuse my ignorance.....

What is the difference? How can a thermostat cause damage?

I was looking around online, is the Honeywell Vision Pro 8000 a good choice? Do the remote sensors actually make adjustments to the t-stat settings or just indicate a temperature in another room?

[travisfl]

The new Honeywell Vision Pro thermostats are probably the best 'stats available today for the residential user.

You can wire up to nine indoor sensors (within 200 feet) - the temperature of all sensors is averaged and compared to the setpoint. If an external sensor is used, the internal temperature sensor at the thermostat is not used.

http://www.hotfreshcool.com/Product/...0(68-0280).pdf

[dnt]

I would check the mounting of the thermostat before I invested big dollars in a honeywell. Sometimes the installer will knock out a good size hole for the wires and not seal it, this allows unconditioned hot air from inside the wall cavity to influence the thermostat readings, the hotter the ambients the worse it gets. Remove the thermostat and look behind it, if the wiring penetration is unsealed caulk it up remount the thermostat and you should see a big improvement in your situation. I have seen this happen quite a bit especially on second floor thermostats, the attic heat tends to migrate down between the walls.

[tpa-fl]

BDR: the Lux thermostats are very poorly made and have a nasty habit of getting stuck in the on position. Read the link I posted to read about all the damage which has occured. DNT makes a good suggestion about ensuring air from inside the walls/attic doesn't reach the thermostat, but you need to get that Lux stat out of there no matter what. As far as spending "big dollars" on a Honeywell thermostat, it's cheap compared to the damage that a runaway thermostat can cause, not to mention the improved comfort & efficiency of better controls.