Smarter Programmable Thermostat?

[John]

Are there any thermostats (any type) that are smart enough not to turn on the heat at 10:55 when they are programmed to set back at

11:00? It seems wasteful and hard on the equipment to do so.

Also for heat pump thermostats, are there any out there that will not activate stage 2 (electric aux heat) during normal setback recovery. If it is 45 degrees outside, I don't want the aux heat immediately coming on every morning just because the thermostat is set to warm the house to the morning temp setting.

[buffalobill]

[trader4]

The honeywell touchscreen models are also fully programmable and I believe will solve problem number 2. Not sure if any solve #1 though.

But, I don't think #1 is that big of deal. If the heat comes on 10 mins before the setback, all that means is the house will have a little extra heat, so the heat won't need to come back on for a little longer during the setback. In essence, it means the setback period could have been 10 mins longer, but that diff is so small it's not going to amount to anything really.

[Bubba]

Plenty of them out there. Honeywell, White-Rogers, etc. You just have to stop buying that cheapo stuff for $40. Get a real stat. Upwards of $100 and a 5 yr warranty. Bubba

[dnoyeB]

White-Rodgers. It can turn on or off this feature. Also it can turn on fan full time during certain periods. In summer I leave my fan on all night, but not during day. raises humidity in house, but it costs less.

[edlisal]

I have a Honeywell CT3611R that I use with my heat pump. It has "Smart Response Technology" that turns the heat pump on early so that it gradually reaches the target temperature by the time you program without using the strip heater. It has been a huge savings for me. You can see one at:

I'm sure you can search and find one cheaper also. I have to say that I bought mine on E-bay for around $22. It was new in the package and has worked great for 2 years now.

HTH, Lisa

[Goedjn]

And, in fact, having a thermostat that's smart enough not to come on within 10 minutes of the set-back period is *EXACTLY* equivilent to setting the set-back period 10 minutes earlier.

[Tomes]

In this case I would just set it for 10:55. The time set is when the instruction changes. Tomes

[LDC]

I think you missing the problem as that doesn't solve anything. Regardless of what the time the change is set he is trying to find a stat that is smart enough to avoid a 2 or 3 minute truncated "on" cycle at the end of a program period by anticipating the pending change.

Using made up numbers, the stat would only come on if it could get a full

10 minute or longer "on" cycle, So while the program setting changes at 11:00, the latest the unit would come on would be 10: 50. If the unit was already running at 10:50 it would continue to run as long a necesary up to 11:00. If the unit was off at 10:50 it would anticipate the 11:00 change and would not start an "on" cycle..

[Tomes]

.... and this is exactly the same as setting it to 10:50. Really, it is. The same things are happening at the same times. Tomes

[LDC]

Of course it is not the same as moving the shut off time up 10 minutes.. Because now you get the short cycle at 10:47. OP wants to avoid the unnecessary short cycle, not move it earlier.

[Mark Lloyd]

For some strange reason, a lot of people seem to think they've solved a problem when they've just pushed it around a little.

That could go on forever, and you're no closer to a solution.

[Mark Lloyd]

My thermostat (a RCS remote-controllable unit) avoids short cycles, but in a slightly different way. It just does not turn off the heat until a minimum time has expired. This may cause it to run a little past the setback time. It also assures the minimum off-time for an AC compressor.

[John]

No it's not, since you don't know when the last cycle will begin. In other words, if you set the set-back time 10 minutes earlier, that wouldn't prevent the thermostat from calling for heat one minute before that. What I'm looking for is either the thermostat not calling for a new heat cycle if it's within x minutes of the setback time, or keeping the equipment on for a minimum cycle time, even if that means continuing to operate for a little while after setback time.

[John]

"Bubba

[John]

Sounds good! What model # do you have? I like the programmable fan feature.

[John]

I'll look into that model. I once used the single stage CT3600 (same series I think) for a gas boiler operation. One thing I liked about it was that it kept a daily and a resetable log of the time the system operates. The Honeywell 8611 has the "smart response technology" too, but it doesn't seem smart in my case.

[John]

That's great, but that's not what I'm looking for, since a call for heat at

10:54 is the exact same scenario in your case. The exact time of the setback isn't important, prevening an unnecessary short cycle by turning on just before setback time is.

[John]

No it's not, because the thermostat calling for heat at 10:49 with a setback time of 10:50 is the same issue. The time of day isn't important, preventing the unnecessary short cycle is.

[John]

activate stage 2 (electric aux heat) during normal setback recovery. If it is

45 degrees outside, I don't want the aux heat immediately coming on every morning just because the thermostat is set to warm the house to the morning temp setting.

Fascinating, because that's exactly the model that prompted my question! The house has one Honeywell 8611g and one Lennox branded Honeywell thermostat that looks to be the exact same thing. (I'm not sure if the Lennox branded one has any additional features, doesn't appear to and the instructions are very basic). In both cases a normal setback recovery causes the AUX heat to come on, which consumes a lot of energy unnecessarily (and also ramps up the fan to the noisy high setting).