Looking for a Honeywell thermostat configuration genius/guru

[aaiyar]

My 2-stage heat-pump is controlled by a Honeywell T6 pro z-wave thermostat. I'm generally happy with it, but would like to make one change.

Right now, the heat-pump (in both heating and cooling modes) comes on in Stage 1, and exactly a minute later switches to Stage 2. After running in Stage 2 for a while, it goes back to Stage 1, and then turns off. An example of this is seen in the profile below (from a Sense energy meter) - I have annotated the relevant portions.

I would like to increase the length of time before Stage 2 kicks in, but cannot figure out a configuration option to do so. Right now, Stage 1 is configured for 1 cycle per hour and Stage 2 for 3 cycles per hour. Are there other settings I should change, and what are they?

I want it to run longer in Stage 1 because longer runs improve dehumidification in cool mode. Currently, the average cycle length is about 20 minutes.

Thanks!

[neonturbo]

@aaiyar

Honeywell T6 pro z-wave

Go into the installer setup. (hold menu button for 5 seconds and scroll <>)

What are ISU numbers 305, 306, 340, 350 set to?

[aaiyar]

@neonturbo

305, 306, 340, 350 set to?

305 (high cool stage finish) - No
306 (high heat stage finish) - No
340/350 - I'm not using Aux heat (it's disconnected)

The two heat or cool stages are purely heat-pump compressor based. And that profile is from cooling (yup - it's been 78-79F here for the last 3 days!).

[neonturbo]

@aaiyar

it's been 78-79F here for the last 3 days

I don't know if I am jealous, or glad that it isn't that warm here.

I don't think there are any other settings that you can set on that particular stat. On the more advanced Honeywells there are upstage timers and upstage deltas you can set. (ISU 3030 through ISU 3120 on a THX9421)

As a test, you might try going to a ridiculously high CPH on stage 2 and see if that makes any difference, at least it might just briefly bump into 2nd and right back to 1st.

My understanding is that when Y2 (cooling high) or W2 (heating high) is active, that it also has Y1 or W1 active too. So if you just unhook high stage, the heat pump wouldn't be aware of that modification.

Therefore if you really don't need second stage at certain times, how about just disabling it via a Zwave or Zigbee relay? Maybe a good job for those cheap 2 relay Zigbee boards? Write a simple rule that if temp in the house isn't being satisfied after 30 minutes, allow 2nd stage? Or when outdoor temp exceeds 90 degrees, allow 2nd stage.

[aaiyar]

@neonturbo

My understanding is that when Y2 (cooling high) or W2 (heating high) is active, that it also has Y1 or W1 active too

Correct. And it is disappointing that there is no staging control (like heat stage differential or cool stage differential) that Honeywell has in the WiFi thermostats.

I have played around with the CPH.

1. If I set stage 1 to 1 CPH, and stage 2 to 3 CPH, then it will start in stage 1, go briefly to stage 2, and then return to stage 1.
2. If I set stage 1 to 1 CPH and stage 2 to >3 CPH, then it will start in stage 1, go briefly to stage 2, return to stage 1, and then go back to stage 2 before briefly returning to stage 1 and turning off.

The relay is an interesting idea. It would only have to be on Y2 (since Y2 controls stage 2 whether the reversing valve is energized or not - so stage 2 cool or stage 2 heat).

My other choice is to go back to my ecobee, which had much better staging control. Not too keen on this because even with the Homekit controller component in Home Assistant, I don't get the kind of control I can get with the Honeywell.

[neonturbo]

@aaiyar

I have played around with the CPH.

I was wondering if it would do that.

@aaiyar

which had much better staging control. Not too keen on this because even with the Homekit controller component in Home Assistant, I don't get the kind of control I can get with the Honeywell.

Allow me to rant for a second here.

Honeywell practically invented the thermostat. Yet their offerings for smart thermostats are very slim and have limited functionality. Ecobee and others might be slightly better in functionality, but for my system, I don't know how I would be able to use any of these Zwave or Wifi thermostats from anyone. Not enough stages, not enough sensors, not enough staging lockouts, and so on.

I love the control I have with the top of the line THX9421 (Prestige IAQ) but it is just awful (and almost impossible) when it comes to integrating with anything. As a standalone device, it is fine. Even with their remote control phone app, it is OK, but not perfect. But you would think that with an internet enabled device that costs at least $400 that you could somehow have an official channel to integrate with other devices.

It is so aggravating when you have so few choices. It is 2021 and I cannot believe that things are so limited in certain smart home areas. Presence detection, thermostats, and other areas just don't seem to get the attention that lightbulbs do. There are 32,871 Wifi bulbs on Amazon, but try to buy a decent smart thermostat!

@aaiyar

The relay is an interesting idea. It would only have to be on Y2 (since Y2 controls stage 2 whether the reversing valve is energized or not - so stage 2 cool or stage 2 heat).

Yep. It would be fairly easy to put one in/near the air handler and would be easily reversible if it didn't have the desired effect.

[aaiyar]

I also discovered that there is at least one other z-wave thermostat (GoControl) which permits much better staging control. Rather than using cycles/hour, it uses temperature delta for Stage 1 and Stage 2 (like the ecobee).

I think your Prestige thermostat also permits staging control using temperature delta/differential. I just wish Honeywell would have done that with the z-wave models also.

[neonturbo]

@aaiyar

I think your Prestige thermostat also permits staging control using temperature delta/differential.

Correct. That is why it is so frustrating, it has all the features and none of the integration ability I want or need.

[Pantheon]

@neonturbo

I love the control I have with the top of the line THX9421 (Prestige IAQ) but it is just awful (and almost impossible) when it comes to integrating with anything. As a standalone device, it is fine. Even with their remote control phone app, it is OK, but not perfect. But you would think that with an internet enabled device that costs at least $400 that you could somehow have an official channel to integrate with other devices.

I could not agree more!

[spartysh32]

@neonturbo

Allow me to rant for a second here.

Honeywell practically invented the thermostat. Yet their offerings for smart thermostats are very slim and have limited functionality.

I’ll add my Bryant system to your rant. Easily the item I think should be automated the most (I.e humidity level based on outdoor temp, etc), but isn’t.