On Friday, January 16, 2015 at 1:25:49 AM UTC-5, Gz wrote:
Nil wrote:
On 15 Jan 2015, trader_4 wrote in
alt.home.repair:

I have two different models of the Honeywell VisonPro series which
have the same kind of adaptive response for recovery from setback.

Then maybe you can answer another question I've been wondering about:
If I reprogram the times and temps, will I also have to go through this
painful training period all over again? What about if I lose power?

I've never seen them come on anywhere near that early. They do
err on the side of getting there a bit early, but overall, it
works very well and if it's early, it's by more like by 20 mins.

That's a big difference - 3+ hours vs. 20 minutes.

Mine were never anywhere near that far off, right out of the box.
They do learn and
adjust though based on experience. I would give it a week and see
what happens.

I installed it 10 days ago, but I only programmed it to my schedule not
quite a week ago. I guess I have to get up very early to know for sure
how much it's adjusted itself, if at all. Maybe it's getting better, I
don't really know, I just know it's not there yet.

Are you sure it's installed correctly? IDK what has to be set on
yours, but mine you had to set whether it was a heat pump system,
furnace, etc. If it thought it was a heat pump for example, it
might fire it up sooner, IDK. I'd review all the install
settings.

I did check out all the fine-tune settings a couple of days after I
installed it. All the out-of-the-box settings were appropriate except
that it was originally set up for a low-efficiency gas furnace. I
changed it to high-efficiency. Otherwise, I think the other settings
were good.

I guess I'll give it a couple more days and monitor it more closely. I
just hate to think of all that expensive heat going up the proverbial
chimney.

I can't think why any difference in furnace efficiency. It would have to
know btu output also and dwelling size, and heat loss. Can you change time
one day and monitor temps while your up ?

Greg

The thermostat doesn't have to know btu output, dwelling size, etc. It
has all the basic info from experience. The thermostat quickly learns
how long the furnace has to run to raise the temp one degree, or two or
5 degrees. That will vary somewhat based on whether it's 10F outside or
40F. If it can raise the temp 5 deg in an hour when it's 40F outside, maybe
it can only raise it 4 deg/hr when it's 10F outside.
But it also knows if it's closer to 10F outside or 40F. How?
If it's been maintaining the temp, then it knows how many mins the furnace
ran in the last hour. If it's in set back, then it knows how much the
temp has dropped in the last 6 hours, the last hour, etc. That's the
pertinent information.

And I don't see why any adaptive recovery program couldn't get the
recovery temp and time close after just a day or two. Just the fact
that it started 2 hours too early the day before, like the OP is
saying happened is a huge input.
It ain'r rocket science to have an algorithmn that say, OK tomorrow
cut that time in half. Adaptive recovery isn't worth spit if it's
that dumb.