Wyze thermostat temperature overshoot

Appears the use of ‘rounding’ is part of the cause of overshoot (at least for half a degree). I would expect the thermostat to read 70 all the way to 70.9 degrees, and only go to 71 when it hits 71. Maybe I am missing something, but I think they should be truncating or rounding down.

If you have a gas furnace it is common for the fan to run after the burner is off to cool the heat exchanger. This can bring the temp up another degree maybe 1.5 degrees. I really expected Wyze to learn that hitting 70F means turning off the furnace at 69F so it would “coast” up to 70F. Instead, it seems to wait until 71F or 72F then turn off the furnace and then you coast up to 73F.

This is so obvious it makes me wonder if Wyze is starting to roll out products faster than they can test them. I have a couple of other pre-orders in the pipeline… I guess those will let me know.

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My thoughts exactly!!! I’m running a gas furnace, and Wyze should’ve known to turn it off a degree or two before reaching the set temperature, instead of after. You literally spelled it way better than me and I can’t thank you enough.

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I’m with you, My old school programmable was working fine, I just love Wyze stuff so I wanted to check it out but so far I’m pretty underwhelmed.

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Interestingly enough, I’ve been comparing active heat with the stats from my previous thermostat and it looks like they are averaging the same or nearly the same run time in similar weather so regardless of the overshoot it’s not actually resulting in more cost.

I’m also curious folks have coast to cool turned off or on. I found that when I had it active there was difficulty reaching the set point but when it was off it goes over. Makes me wonder if Wyze is treating the temp as a comfort range rather than two specific set points and accepts anything within that range as correct.

@WyzeChuan any insight you can provide with this?

So I picked up a digital thermometer with Bluetooth time series tracking and placed it right next to my Wyze tstat.

  1. Set point at 69 during day and 67 at night (except for a couple hours last night when I showed my wife how to manually control temp and she promptly changed to 71 :thinking:)
  2. Behavior on Better Comfort
  3. Not using Cool To

Observation. While Wyze tstat actual temp tends to display +/- 1 degree swings from 68 to 70 degrees (due to rounding up), the digital thermometer is consistently +/- 0.5 degree. So when @WyzeChuan say temp differential is +- 1 degree F, I’m thinking that’s the deadband so +/- 0.5 degree from set point.

Pics below

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So…any updates from the Wyze team yet? Newer firmware? Or are we better off returning the thermostat?

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I don’t expect we’ll see any updates for a few more weeks.