Thermostat Scheduler won't operate properly in Celsius

After many attempts to get my Honeywell T6 Zwave thermostat (https://products.z-wavealliance.org/products/2893) to work correctly, I have finally found a solution. I originally put my thermostat in Celsius Mode since my hub was set to Celsius in the Main Settings. This resulted in the set heating temperature being set to 4.5 degrees Celsius (very cold almost freezing) when coming out of away mode. Coming out of away mode should of set the heating temperature to 22.5 degrees (nice room temperature) as dictated by the scheduler app. Honeywell documentation states that 4.5 degrees Celsius is the lowest temperature the thermostat can be set to.

Setting the thermostat to display Fahrenheit and setting my hub into Fahrenheit and then re doing all my temperature inputs in the app into Fahrenheit has solved the problem. Everything is working as it should.

This definitely seems to be a bug in the Thermostat app that does not allow operation in degrees Celsius. Hopefully this can be fixed so I can go back.

Thanks, Stephan

I just had a quick look at the thermostat schedular code, it doesn't appear to do any temperature conversions, which it shouldn't have to.

So what driver are you using for this thermostat, and does it operate correctly in C from the driver details page?

I confirm that Thermostat Scheduler with Celsius it's working fine, so it's something driver related.

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I'm using a Tado thermostat with Celsius and not seeing the same problem.
Doesn't help you I know but just thought I'd post for information.

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Using "Generic Z-Wave Thermostat" as the device driver. Just set everything back to Celsius (hub, scheduler, and thermostat) and it appears to be working properly. :slightly_smiling_face:

It does operate correctly from the driver page in both Celsius and Fahrenheit.

The only odd thing that is still happening is when I enter a temperature in the scheduler and hit enter it returns a value with two decimal places (I entered a whole number with no decimals) here is a screen shot:

This is no big deal, if I re-enter the number a second time it comes back with a whole number. This never happened when I was working in Fahrenheit.

I wonder if it is possible that during testing I was asking the thermostat to call for heating too many times within a single hour. When installing the thermostat, I first set-up some preferences before connecting to the hub. One of the preferences I set was a maximum of 3 heating cycles per hour (and two cooling). Maybe, through testing, I was inadvertently having the hub call for more than three heating cycles per hour, which was then having the thermostat return the minimum heating setpoint allowed on the device i.e. 4.5 degrees celsius.

Thanks for looking at the code, it is appreciated. I will report back if the problem reappears. After having my hub for a little over a month and installing 38 devices I have to say HE is one of the best purchases I have ever made. Other than a few hiccups and getting used to making logical sequences for rule manager, it has been a fairly painless endeavour. My WAF is a 9+, that says it all!!!

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Stephan.J
Installed a Honeywell T6 Swave last night. Works perfect in Fahrenheit. Coming out of Away mode works perfect.
Could not get it to work in Celcius. I may give another try later today.
Your post saved me time. Thanks.

@mike.maxwell
Installed the Honeywell T6 Zwave Thermostat. Using the Generic Z-Wave thermostat driver.
Works perfect in F and C except when you enter half degrees in C from the Thermostat Scheduler: then the thermostat will be set at the lowest temperature it is configured for and not what is entered in the Scheduler. No error messages.
With the thermostat in C and the hub in F, everything works and the thermostat can be set in half degrees C.
Any changes made in the Thermostat Scheduler, will show immediately on the thermostat and on the tile. This works really well.

if you enter half degree C in via the driver details does it work correctly?

Yes it does.
Hitting the up or down buttons from the tiles changes the temp in half degree steps.
There is something odd though. Using the tile:
Staring from 29.0C and hitting the down arrow once:
Shows 28.5C, then shows 29.0C and then shows 28.5C.
It does not do this every time and I have not figured this out completely. Maybe this is irrelevant for the 0.5C steps but thought I would mention it.
Any testing I can do to help, let me know.