Thermostatic Controls - Honeywell Thermostat T8000C Issue

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View Full Version : Honeywell Thermostat T8000C Issue


MellowNinja
10-05-09, 08:25 PM
My wife and I are new house owners, and this is the first time I really had an issue that I need to solve for thermostats & A/C.

Here's the issue:

Currently, the thermostat reads the room temp at 70ºF. I have the system set to Cold with all the wakes, returns, leaves and sleeps set to 79ºF.

The fan continues to cycle on and off, even when the room temp is at 70º, which is clearly below the setting for 79º. Is it normal for the fan to cycle like that? Living in apartments for years, the fan would not turn on until the room temp matched or went over the desired temp setting.

Also, the fan cycles when the system is set to OFF mode. Does it cycle in OFF mode automagically to help fight stale air?

Thanks for the help in advance. Just want to know if there's something I can do to fix this if it is a real issue.


Houston204
10-06-09, 06:30 PM
Your thermostat does not have that circulating function.
I'd say your thermostat is failing.


http://i151.photobucket.com/albums/s160/Houston204/HoneywellT8000C.jpg


I recommend a Honeywell RTH6300, RTH7500 or a RTH7600.

http://i151.photobucket.com/albums/s160/Houston204/HoneywellRTH6300B.jpg

http://i151.photobucket.com/albums/s160/Houston204/HoneywellRTH7400heatpump.jpg


http://i151.photobucket.com/albums/s160/Houston204/HoneywellRTH7600.jpg


Color codes vary.

Jay11J
10-06-09, 09:01 PM
Before we jump the gun here on a new t-stat, as Houston has shown your model t-stat, remove the G wire for a short time to see if the fan runs. before you do this, does this happen when the t-stat is in "OFF" mode?


MellowNinja
10-07-09, 07:03 AM
Thanks for the info.

Jay: Actually, yes, the fan does cycle in off mode. That's how I noticed it.

And Houston, you're sure that thermostat does not have a cycle feature? The installer called me yesterday to inform me that they installed these thermostats in the home with a cycle setting, which has the fan cycle once every 15 minutes for a duration of 2 to 3 minutes.

Thanks again for the help.

Jay11J
10-07-09, 07:47 AM
Ok, it may not be the t-stat.. You may have another control added to the furnace.. Chance you may have a "Fan Cycler" control tied to the furnace.

Look around your furnace for something like this.

http://img233.imageshack.us/img233/8885/catac9.jpg

If you don't see it, then for test, remove the G wire from the t-stat, and see if that stops it.

MellowNinja
10-07-09, 07:56 AM
Jay, thanks. You know, we moved into the house in August, and when I had the inspection, I vaguely remember seeing something like that.

I'll check it out when I get home tonight. Again, thanks for the help. Hopefully I'll have a resolution to post.

Jay11J
10-07-09, 08:02 AM
Let us know what your results are. FYI, if you undo the G wire, make sure you don't have it on "COOL" mode, otherwise, you'll freeze up the coil.

Houston204
10-07-09, 08:49 AM
http://customer.honeywell.com/TechLit/pdf/68-0000s/68-0195.pdf


I don't see any circulating feature in the stat manual, but this does not rule out the additional controls that Jay mentioned...

http://i151.photobucket.com/albums/s160/Houston204/HonT8000cfanswitch.jpg

MellowNinja
10-07-09, 05:14 PM
Ok, it may not be the t-stat.. You may have another control added to the furnace.. Chance you may have a "Fan Cycler" control tied to the furnace.

Look around your furnace for something like this.

http://img233.imageshack.us/img233/8885/catac9.jpg

If you don't see it, then for test, remove the G wire from the t-stat, and see if that stops it.

Jay, I do have that control near the furnace. So far so good. Now I need to find a flashlight since the bulb is out up there...

Jay11J
10-07-09, 08:13 PM
Here is the manual (http://www.ntsupply.com/files/products/Aircycleruserguide.pdf) for it.

You can change the time if you wish.