I have a two stage Honeywell Vision Pro Thermostat, Model TB8220U that is connected to my American Standard two stage high efficiency furnace. It is programmed with the adaptive recovery option turned on. Overall, I like the thermostat and the display is certainly easy to read and use.
I've noticed the following quirks:
- Even when the outdoor temperature is consistently COLD for several days, the thermostat seems to miss its target because it starts the recovery mode about two hours prior to the target time. In other words, it doesn't seem to adapt to the increased time needed. I don't have an outdoor temperature sensor, but I remember reading that the thermostat only uses an outdoor sensor in its calculations when it is used for Heat Pumps, is this correct? (Option 340). It would be convenient to see the outdoor temperature on the screen though.
- What is the difference between Option 680 "Temperature Control Heat" (Less Aggressive, Standard, More Aggressive) and Option 685 "Recovery Heat Ramp Rate" (Degrees per Hour)? Degrees per hour sounds pretty self explanatory but I'm not sure what aggressive temperature control is.
I've noticed that the furnace will go into recovery mode, at some point will ramp up to Stage 2, then slow down, then turn off, then repeat the process, all during the recovery time. ("Recovery" is displayed). Unless the outdoor temperature became much warmer (it hasn't), why does the thermostat use stage 1 unless it learns that it's going to need more heat to reach the target on time?
- If the displayed temperature is within 1 degree of the set temperature (including the old temperature if it is recovering), the thermostat displays the set temperature as the current temperature. For example, if it is a constant 68 room temperature and I set the thermostat to 69 degrees, exactly two minutes after I do this, the displayed temperature will also change to 69 even if the furnace didn't turn on. Turn it back down to 68 and exactly 120 seconds later 68 degrees will be displayed again too. I would much rather the display to be accurate instead of changing to make me feel better. Is there any way to disable this "feature?"
- If setback time is 11:00 PM, the thermostat may still turn the furnace on at 10:58 only to shut it off a minute later with no real heat added to the house. Why doesn't the adaptive thermostat realize that the set temp is about to go down and short cycling the furnace is pointless?
- The thermostat has daylight savings (Option 330), but was purchased just before the dates were changed by the government. I know later models have the new dates, is there anyway to add this to an existing thermostat? Honeywell wouldn't say much.
Are long cycles better for the furnace longevity than shorter cycles? Does the igniter's expected lifetime decrease each time it is used? What is the best combination of settings 680, 685, (others?) for longer cycles?
Thank you very much!