Thermostat

[Joe]

Since i own a bit of Honeywell stock I think that's what you should buy. Of course, they already have a fine reputation for dependability if that's important to you,

Joe

[GregS]

I think you can also fiddle with them to get a different setting, like mount it off angle.

I have used the programmables, and its great when needed. Right now, my smaller house heats up much faster than the old. For the most part having the automatic function is not necessary, and I just set it when I come or go.

greg

[GregS]

I am pretty sure my White-Rodgers has a relay as I can hear it plainly, and it lasts well over a year with summer cooling. A relay provides isolation and a ground loop withing a system. A SS can also be used isolated if its wired like that and does not run the thermostat on the AC 24 volt line.

They took my LUX off when I had a new system installed and they used the White-Rodgers. I was going to reinstall the LUX but I never did. I never learned to program it, but the .5 degree differential is the standard setting, but you can set it to 1 degree. Some go up to 2-3 degrees. The more the furnace turns off and on, the less efficient it becomes to a certain extent. They tried to make off with my LUX, but I got it back!

I seem to now recall the old Hunter did have a fail safe. Some kind of extra mechanical fuse or thermostat to prevent the house trying to go up over 100 degrees. The furnace has an internal temperature shutoff on the heat exchanger, but I don't know, the newer types may also have another sensor on the air flow temperature. I think my furnace may have an air flow meter to help control fan speed. A fail safe cannot be part of the circuitry controlling the temperature. It goes in series with it to become a totally different fuse or system.

I guess I have a certain affiliation with Honeywell, as I used to work for a Bendix outfit that eventually got hooked up with Honneywell.

I work with a number of non time programmable conrollers. They are just programmable for real time and don't care anything about time, except for time to heat to temperature. This is the PIR functions to control heat and overshoot. They often have a AUTO mode where the PIR functions are automatically entered by the processor after initial parameters are inserted. Some controllers also have fuzzy logic to become smart, and can modify settings to improve performance.

Having a thermostat heat to BE a temperature at a certain time can have benifits, but you have to really be aware how the thermostat works so you can compensate for the way your mind has been working in using thermostats that don't have this feature. The old house used to take up to an hour to heat to temperature, I understood this. A smart thermostat can figure that out by itself once it gets going, and remember.

greg

[Tony Hwang]

Hi, When baterries getting low it gives more than a month's warning. Default setting is imbedded in the non-volatile memory.

[trader4]

Nothing to be worried about if the battery fails while the furnace is running. Without power the thermostat is off. If you pulled the battery while the thermostat was closed and calling for heat, the circuit goes open and the furnace will shut off.

The other problem, which is loss of battery when freezing could occur is a problem. But many of the digital thermostats have a backup mechanical switch that will close at around 40 deg.

With millions of these in use for decades now, they apparently are reliable and safe or you'd hear about it.

[Newbie]

: I'd avoid Lux or other cheap brands.

Interesting to hear this sentiment expressed quite often in this thread as Consumer Reports had two Lux models as Best Buys.

[Ed Pawlowski]

Thank you for affirming my reasons to no longer buy CR.

Frankly, if it works and cost less, it would be a best buy. Too many people have had too many problems with Lux over the years to take a chance, IMO.