Beware the Repairman

Share your Sense stories
#1

Another Sense success story:

Background

I live in NW FL and yesterday we used heat for the first time since February. We have upstairs and downstairs electric heat pump systems, both with secondary 10kW electric aux heating coils that are supposed to engage if the heat pump can’t handle the load quick enough. Without the aux heat, the heat pumps use about 2.8kW. Thus about 12.8kW when the aux heat is engaged. The heat pumps work very well without aux heat and we rarely need it. Most years aux heat never comes on.

Discovery

Sense warned me that we had a spike about double the highest level seen since I installed it this summer. Turns out the upstairs heat pump system was turning on the aux heat whenever the heat cycled even though it wasn’t needed (only 1 degree room temp corrections). I looked up the thermostat data and it turned out to be a model that is incompatible with secondary (aux heat) systems. An AC repairman changed out the thermostat over a year ago (!) during a repair and it seemed to work fine.

Correction

A trip to Home Depot for a proper thermostat fixed it. See attached - similar outside morning temp’s, but a huge reduction in power usage.

Aux Heat
Aux Heat2418×1754 255 KB

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#2

What thermostat did you have and what did you go to? I had Nest back before they were bought by Google, and have Honeywell for a year now. The Nest user experience was a lot slicker, but Honeywell has the variety I needed (5 different thermostats). Of course ecobee has the Sense integration, but so far I’m good with Honeywell.

#3

I’m not interested in wifi enabled thermostats yet, but as a result of this incident I did study thermostats and multi-stage heating and cooling systems pretty thoroughly before settling on this.

The Home Depot purchase turned out to be temporary because I wanted more control than what they had to offer. Sorry I don’t have info. on the initial thermostat that was causing the problems - threw it away. Some generic Honeywell unit. You know how this stuff goes…

My two heat pumps have electric aux coils inside the single indoor air-handlers, thus are considered two-stage heat systems with single stage cooling. Fairly traditional setups and Sense had no trouble finding them.

Low level adjustments listed on pp. 10-11 of the Installer Manual.

User level adjustments listed on p. 9 of the User Manual.

All adjustments are well explained in both documents. The unit is well made, logical, uses AA batteries for backup or for normal operation if you don’t have a “C” wire (common 24V AC transformer wire) in your system. The company obviously caters to professional installers and provides the most control I could find.

#4

Too bad that thermostat does not have a humidistat feature, I would have liked that and will research additional models.

I installed the Nest thermostat a few months ago and was initially impressed with 'Smart Home" and new technology but recently discovered that I couldn’t simply set a temperature and hold that setting. The schedule is constantly trumping my choice and there is no way to suspend that.
Then, Nest has a “run to dry” humidistat feature, but I do not have control over that either. So if the humidity is such, the Nest could potentially make it snow in my Florida home before the humidity that Google has determined acceptable is attained.
I am likely going to return Nest to Home Despot and get / try an Ecobee. I like the idea of smart home wifi as I work offshore and choose to monitor / control the home from anywhere in the world where there is connectivity…
Cheers!

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#5

If I can ask, what is it you don’t like about wifi thermostats? We don’t always keep out basement heat on, as between being in the ground and the radiator pipes running through it, the lowest it has gotten so far is 63°. When we’re down there watching TV though, we like it at 70°. With the wifi thermostat we have that controls essentially a spaceheater, we can turn it up while we’re making dinner and by the time we get downstairs, it has heated up the basement. Nest had the ability to do both schedule and geolocation, but the Honeywell system is one or the other. That is a little annoying, but since we’re both always home right now, I turned on schedule and will worry about office hours when we’re back in the office, whenever that is.

#6

Just my preference for simplicity** - unless a gizmo adds something I consider valuable enough to override this preference. I’m very happy with the comfort and power management features of the non-wifi units (now that I’ve studied them) and don’t need remote control. Cost (at this level) is unimportant to me, so that’s not part of it and likely one of the reasons I consider Sense to be a gift. : )

** re: Simplicity. I really dislike (borderline hate) stuff that tries to think for you without thoroughly explaining the logic employed.

#7

No to digress too much, but 2-3 years ago I installed 2 Nest thermostats (and linked to my iphone). Then, the following February I went for a 1-week business trip to Mexico. Got a call from my wife that whatever she did she could not keep the house warm. Somehow Nest decided I was away and did not need the heat. It took some ‘fiddling’ with the schedule etc, but we got it to work. Of course, once Covid-19 hit, and most of us are at home, I had to correct the schedule once more. The weakness in Nest (and any others) is that the heat is turned on/off based on where the thermostat is located. My office would get very toasty whereas the dining room (where the thermostat is located) would still be ‘cool’. I recently got 3 remote temperature sensors for the Nest. They do make installation easy, but sometimes it’s difficult to get it working right. At least, to those of us used to plug-n-play and not having much patience to read all the steps in the instructions.

I do not like it either when the devices do the thinking for me, but to me all of these ‘smart’ devices, be it light switches, thermostat, sprinkler, or even pre-heating the oven … they enable me to change things remotely, from the comfort of my phone … that’s a big plus (when things work).

#8

@drjb, I had Nests for a bunch of years but finally replaced with Ecobees about 4 years ago for 3 reasons:

  1. Remote sensors - Ecobee thermostats can be set to respond to different temperature / motion sensors in different areas of the house during different “comfort periods”, and even based on motion/occupancy. We had the same problem of wanting our bedroom temperature to control the heating temperature at night, not the temperature at the thermostat.
  2. Manual control - Ecobee allows much more manual control and programming than Nest - Nest magic is great when it works, but level you with little recourse when it doesn’t. Ecobee allows far more manual tweak, especially with the aforementioned sensors.
  3. Data access - Ecobee give you access to 5 min resolution data about heating / cooling operation. That means one can do cool analysis like Sense detection vs. Ecobee commands (below). Nest/Google doesn’t really give you access to that data AFAIK.
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#9

Not a digression at all @drjb - rather helpful info. actually. : )

The Breaburn 5020 I selected does have a remote sensor option, but it’s wired of course. The concept of remote sensors seems like a bit of a half-step to me, what did make a lot of sense was the option this thing has to program the fan to recirculate the air in the home according to taste even when the unit isn’t heating or cooling. This has two benefits:

  1. Distributes the heat/cooling throughout the home more evenly.
  2. Cleans the air more due to the filters.

Our downstairs thermostat is in the living room and in the past we used to adjust it so that the kitchen and downstairs master bedroom were reasonably nice as well. Even after throttling the registers (vents) in the living room, it was never as even as I would have liked. We accepted the situation because I didn’t want the noise (minimal) and expense (probably unacceptable) of running the fan full-time.

Our air-handler’s fan dissipates about 160 watts running by itself and now the thermostat runs it for 12 minute cycles every once in a while when the heating/cooling isn’t running and the entire downstairs has very consistent temperatures at a minor increase in power usage. This is a great deal IMO and the air seems fresher - but that latter point could be mental. : )

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#10

FYI - Ecobees also have the option of programming for an minimum run of the fan/air handler every hour, when AC or heating isn’t reaching that minimum. I set for 5 min per hour. And I agree with @lholland that that makes a difference.

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#11

@kevin1. That’s a very good point about the Ecobee. The Nest Remote sensors only sense the temperature of the room they’re in, nothing else. What would be really neat is a combination temperature+presence sensor (PIR or else). Because, in all honesty, I do not have a ‘fixed’ room I stay at. I wonder if anyone makes such combination (Temp + Presence) … if not, please do. I have to think this through though as the last thing I want is for a sensor to track my position and heat the room accordingly. Heck, I might as well carry the sensor in my pocket.

#12

@drjb,
Ecobee makes a combo temp / proximity sensor that works well, plus also works with HomeKit.

Keen has a good combination sensor as well, but they are primarily for control of the vents, but don’t report back to the thermostat. Ecobee smart sensors do both - work with the thermostat and control Keen smart vents.

Google/Nest has their own ecosystem and finally has smart sensors as well, but about 4 years late for me.

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