ADC Thermostats
For those of you in the alarm.com ecosystem, I’m sure you are very familiar with the ADC thermostats and temperature sensors. They typically are very feature rich with many advanced parameters. The biggest limitation has been that all the ‘smarts’ are trapped in the alarm.com cloud and not really available from the thermostat itself. But we’ve lived with that for a while and rely on the awesome robustness of their cloud.
I have the ADC-T40K and while it looks pretty on the wall, I never really touch it. Now that its setup its fully automatic. Even temporary temp changes we usually do from the ADC app on our phones. I do wish, however, I could do more on that touchscreen. Sort of a waste. And, it was expensive. And, luckily I have a c-wire, as there is no battery option for the T40K.
The ADC-T2000 has been around a long while, and offers a battery option. It, like the T40K, can support a wide variety of system types.
Now there’s a new thermostat the ADC-T25
Alarm.com just announced the new ADC-T25 thermostat.
It accepts a C-Wire or battery, and looks similar to the S2000 and is about the same price.
But I don’t think it is a replacement for anything in the line-up. It seems to be for a special subset of users.
Here’s a link to the press release and the info sheet:
Strange Limitation
Certainly this was just released and I don’t have one in hand. However reviewing the spec sheet revealed an odd limitation: an insufficient number of wire connections ?
Here’s a snapshot of the wiring terminals on the back:
And the spec sheet says it supports:
Too much on the Z terminal
If you look closely, the Z terminal is for all of the following uses:
- W2
- Y2
- O/B
- Humidifier
- Dehumidifier
- Vent
This would imply that you’d have to pick ONE function for this terminal, I would assume. This means that if you have 2 stage heat (fossil) and 2 stage cool, this thermostat will not support your system.
Or, if you have a heat pump with backup heat strips, 2 stage AC, and a humidifier - you’d have to give up something.
Or, if you have 2 stage heat (fossil), single stage AC, and a humidifier, you won’t be able to control humidity with this thermostat.
… you get the idea.
Of course it could likely be jury-rigged to work (like having your heat calls always be second stage and ignore stage one option, so you could use the Z terminal for your second stage cool, etc) but I wouldn’t recommend losing system features for the sake of a stat.
So why?
What do you think? Am I misreading this, or was this an intentional limitation to push most people to the ADC-T40K? Or do most users just have plain ol’ 1 stage heat and 1 stage cool and I’m just spoiled?
[Or maybe most folks these days have a heat pump and I’m stuck in the fossil fuel past. Which is certainly possible… I’ve been accused of being old school before.]
I see it as a strange limitation. It does make me wonder if they will release an additional product soon that accepts batteries and has all the terminals of the T40K.
All they had to do was give us a distinct Y2 and W2 terminal and it wouldn’t have even caught my eye.
PS: If you want to compare, the T40K has the following terminals:
