Help with Thermostat

[rbeermann]

i've had the c4 thermostat installed in my house for about a year now without any issues. just recently, the battery died out, so i replaced it. Within 24 hours, the new battery died. THinking it was just a fluke, I purchased a new one. Same issue. Any thoughts out there? Thanks!

[RyanCB]

I would check your furnace, sounds like the fuse might be blown if it was power stealing.

[henniae]

beermann

Ryan makes a good point about checking the breaker. Since you live in Tampa and it is August and probably hot. if the breaker were blown you probably would not have any AC and notice that immediately.

Several thing I recommend that you check and verify are

1. Is the t-stat running off battery? Is the little battery indicator on the display lit?

2. Is the t-stat power steeling or using a common wire.

3. What software version are you running?

4. Any software updates lately?

[rbeermann]

Thanks for all your input, guys.. Here is what I can determine. I am very ill-educated on AC/heating, so bear with me. I did not install the tstat myself, and my dealer is out of business.

1. Is the t-stat running off battery? Is the little battery indicator on the display lit?

--The t-stat has the battery symbol only when the AC is running. When the cooling shuts off, the battery symbol goes away. I am assuming that it only runs off of the battery when the air is on.

2. Is the t-stat power steeling or using a common wire.

--I am not sure about this.

3. What software version are you running?

--1.7.3.20

4. Any software updates lately?

--no

I would check your furnace, sounds like the fuse might be blown if it was power stealing.

--will do.

[henniae]

1. Is the t-stat running off battery? Is the little battery indicator on the display lit?

--The t-stat has the battery symbol only when the AC is running. When the cooling shuts off, the battery symbol goes away. I am assuming that it only runs off of the battery when the air is on.

Based on your responses I would say that you are using power stealing. Depending on the exact model of the t-stat there should be a little switch to enable or disable power stealing.

Do you have heat in this system? Based on the info above I am inclined to say no. When that AC is on the only path for power when the t-stat is using power stealing is through the wire used for heat. Since the battery indicator comes on when the AC is on I think there is no connection for heat or the connection could be bad.

If you pull the t-stat off the wall look at the following

a. What wires of what color are hooked to each of the terminals of the t-stat? The following is the most common standard. See the image I included.

RH/RC = usually red

G = usually green

Y1 = usually yellow

W1 = usually white

b. Is that a little U shaped jumper between RH and RC?

c. How many total wires are there? And what color are the wires.

[rbeermann]

Here is a pic of what I have going on. The t-stat is the CCZT1W. I know that it was the first generation of tstats C4 came out with. There is a bridge b/t RC and RH, but there is also a bridge between Y1 and W1. I do not see a switch to disable/enable power stealing. I do have heat in this system, but it is very rarely used.