Installing Tstat Question

I would like to install a z-wave tstat in the basement - for the most part, to keep an eye on the temp, and of course kick the heater on when needed.

Thing is, I have a 1960’s Sears in-wall gas heater unit (had it checked out and all is good, works well) with a Sears heat only mercury switch thermostat. The installed thermostat is shown in the pictures.

Can I use the CT-30? Picked it up super cheap and would be a shame not to. As you can see, there are only two wires and they aren’t labeled.

I was going to use an external transformer for c-wire too so the tstat would act as a repeater. I see that would go to C and RH.

Well, after much research and delving back into the 1970’s, I can’t use the CT-30 or any other low voltage tstat. I have a ‘millivolt’ (getting 1V actually) thermometer which is what they were using and are still in use today for wall heaters.

That sucks! Any millivolt z-wave tstats? :slight_smile:

My bad…it will work. DOH!

I take it you got it working? How is it running for you?

I haven’t installed it yet. I was going to wait a little bit and grab a 24V transformer I can put into the wall so I can use c-wire capabilities. It’s my understanding that it can’t be added later with c-wire capability unless you take the tstat off the network then re-install it.

I’d like to use the repeater function.

Correct, you do need to add it in with 24VAC for it to repeat

It says in the manual I can use a 12V-24V transformer. Is there a downside to using a 12V one? That’s all I can get my hands on at the moment.

As long as it provides over 300ma that should be fine.

Ok, finally found my transformer. Going to run the c-wire and install the t-stat tomorrow. Will let you know how it goes.

Installed it last night. Used a 24V transformer and ran two wires to C & RC, then connected millivolt t-stat wires to W & RH. It’s nice when you don’t have to worry about polarity. :slight_smile:

Working great!