Wow. I feel like a total sucker now. I have 2 estimates for Carrier equipment, each from a Northern NJ contractor: Estimate 1: AC 2.5 Ton 15 SEER 24APA530 Coil CNPVP3017ATA Furnace 70kBTU/80% 58CVA070-14 Honeywell Vision Pro Thermostat Honeywell HE-265 Humidifier Aprilaire 2200 air filter Replace chimney liner $10,347 Estimate 2 Same ac Same coil Same furnace Replace chimney liner Thermostat unknown no filter no humidifier $10,056 Estimate 3 (Lennox) AC: 2.5 ton 13 SEER (Variable Speed) Coil: C33-31 Furnace: 90k BTU 80% AFUE Thermo: Honeywell PRO 4000 Aprilaire 400 Humidifier Chimney liner replacement $9,610 These include installation into existing forced hot air duct system.

This is great information. Switching to "efficiency" or "maximum" would seem to make it a little less manual than I do now, which is a good thing. I always have to remember to return the fan to AUTO if I've set it it MED or HIGH earlier in the day. I wonder if "Dehum airflow" to "HIGH" would also work. As far as remote sensors go, I have Infinity Model SYSTXCCUID01. I don't see a '-B' at the end, so I hope there isn't that much difference between my unit and the manual. It has pins for remote sensors (S1 and S2). I am having trouble finding which remote sensors are compatible. It looks like there are two models: 1PZONECCORRSSA and SYSTXCCRRSO1. I am finding conflicting postings as some places say they are interchangeable and some are saying that the 1PZONE is for a zoned system and the SYSTX is for Infinity. I was hoping to find some documentation on the sensors to get the specs on the thermocouples, but have only succeeded in finding eBay auctions and links to ebay auctions. Does anyone have any links to documentation or shed light on which sensor(s) can be used? Thanks!

Is the wall sealed behind the thermostat where the wires come through the wall? This could throw off the readings.

Rangerneil, You did not indicate heatpump or AC. I have a Bryant Puron AC system which is the same manufacturer as Carrier. I think your infinity thermostat is the same as my Bryant thermostat. It appears your thermostat was not set up properly by the installer as to the proper outdoor temperature and current humidity levels and possibly the indoor temperature. These three can be reset to the proper settings. You will need an accurate or near accurate thermometer and either a hygrometer or psychrometer to measure the humidity inside at the thermostat location. Do not use any radio broadcast for any of your measurements because they will not be as accurate as the conditions outside of your home. When you check the temperature outside, measure it in a area away from concrete. If your installer placed the Outdoor Air Temperature switch too close to the compressor, it will never indicate the true outdoor air temperature because you will measure the ambient temperature plus the heat coming off the compressor. But I am going to assume the installer placed it away from the compressor. You need to get a decent thermometer and hygrometer and/or psychrometer to measure the humidity. It may be easier and cheaper to call back the installer and have them do the measuring and recalibrate the thermostat. Ask about the location of the OAT if you have one. You should have the installer instructions for the stat. Read through it to see if an OAT is mentioned. If you decide you want to measure using your own instruments, then stay away from those $20.00 hygrometers from either Radio Shack or the home centers as they will be + or - 5 or more percent off from actual humidity. Now take note of your stat's indoor readings for room temperature, outdoor temperature and humidity readings and record them on a piece of paper. Do the same for your actual measurement of outdoor temperature and record that also. You will need both of them when you re-calibrate your stat. But before you purchase anything, check your stat for a advanced settings button. If you have this, then press and hold this button for about 10 to 15 seconds until a install/service menu pops up. On this menu, you should see "Settings" as one of the choices, highlight this using the scroll button. Click the select buttom, usually located on the right side of the stat. The next menu will be the "Setup Menu" with the "Thermostat" highlighted. Select this and another menu called "Thermostat Setup" pops up. As you look down on the menu, you should see "Offsets". Scroll down to it and select it. The final menu will say "Thermostat Setup" again and you will see three offsets adjustments to either raise or lower depending on what your actual outdoor and indoor temperatures are and your indoor humidity offset. The first choice may be the indoor temperature adjustment and the other choice should indicate for the outdoor adjustment and then your indoor humidity adjustment. Use the temperature selection button to make your adjustments. Refer to the readings you recorded on paper and make your adjustments to add or subtract from the thermostat readings. Then you are done. Press the advanced button briefly and you will be prompted to save your settings. Select yes. Afterwhich, your stat should be showing the correct measurements for the outdoor and indoor temperatures and indoor humidity. Hopefully, You have an AC system as I am not positive that a heatpump has the same configuation as an AC system for set up purposes. Then maybe this info can help others. If you have the install/setup booklet for the thermostat (not the user manual) it will explain everything about the advance settings menu's.