Insteon Thermostat changing setpoint

[KirkInSLO]

I’ve been having issues with my Insteon thermostat since I bought it, but I’ve just lived with it as our cold season isn’t very long. I’m tired of living with it and need some help.

 

Setup/Hardware:

 

• Insteon wired thermostat connected to a forced-air furnace. No heat pump, no air conditioning.
• ISY 994iZ controller.

 

Thermostat Programming:

• None. I do everything through the controller.

 

ISY Programming:

 

I have a button on a Keypad Linc labeled “Heat On.” The ISY has a few heat-related programs.

• One sets the thermostat clock once a day (it tends to drift)
• One monitors the status of the Heat On button. When it’s switched on, it does the following:
  • Set ‘HVAC / Thermostat - Main’ Mode Heat
  • Set ‘HVAC / Thermostat - Main’ 68F (Heat Setpoint)
• One queries the status of the Heat On scene, and if it’s on at 9pm, it chimes the thermostat to remind me to turn it off.
• One queries the status of the Heat On scene, and if it’s on at 11pm, it turns it off.
• The last one queries the status of the Heat On scene, and if it’s on at 7am, and day = M-F and holiday mode = off then it turns off the scene.

 

The problem:

 

No matter how the heat is turned on (whether through the Heat On button, or by cycling through the modes on the thermostat), it routinely but somewhat unpredictably changes the setpoint of the heat either 4F higher or 4F lower than the 68F I’ve set. This results in either over heating the house to 72F or setting the thermostat to 64F which is colder than we want.

 

I’ve checked thermostat programming, ISY programming and I’m losing my mind. Has anyone else seen this, and if so, any idea what’s going on and how I can fix it?

 

Thanks in advance.

 

-Kirk

[stusviews]

Disable the thermostat (right click) for a day or two. Darn, you'll have to manually control the thermostat during this time. Does the thermostat still randomly change the setpoint?

[KirkInSLO]

I've disabled it. I'll post the results in a couple of days (assuming my fingers don't fall off from having to manually turn on the heat at the thermostat).

[KirkInSLO]

The setpoint is still changing with the thermostat disabled on the ISY. I notice the "ENERGY" indicator is coming on on the thermostat, which I fear is the problem. Is it trying to adjust the temperature to save energy? I can't imagine how changing the setpoint UP (in heat mode) would ever save energy, but I digress. Any clues on how to dumb-down the thermostat would be helpful.

[stusviews]

HouseLinc offers that option, the ISY doesn't, at least it doesn't for the wireless thermostat. I've replaced my wired Insteon thermostats with Ecobee3's, so can't check that. But if your thermostat is under warranty, then you should get it replaced. Energy mode is not supposed to activate itself.

 

BTW, you're correct about the setback. It should be lower for heating and higher for cooling.

[Teken]

Kirk,

 

For the benefit of the forum members can you state the model, hardware revision, production date, and what the ISY Series Controller indicates as the firmware in place.

[KirkInSLO]

ISY 994i (1120) with OpenADR and Z-Wave

Firmware: Insteon_UD994_OADR v.4.4.6 (UI is the same)

 

Thermostat is an Insteon Thermostat v.0D (2441TH) - wired, which is likely beyond its warranty. I don't think I'll replace it with another Insteon. I'm really unhappy that this thing essentially hasn't worked from the start. I initially had furnace issues, so it sat around waiting to be installed and that gobbled up much of my warranty. I'll reach out to them and see what, if anything, they can do, but otherwise, any suggestions on a replacement? I really want it to integrate with the ISY.

[Teken]

Since you have a Z-Wave enabled controller the world is your oyster! I would probably review the forum threads here and see what hardware meets your budget / value needs.

[stusviews]

I prefer escargot to oysters unless the oysters are alive and the escarot isn't. That's why I switched to thermostats that respond to inaction