ca8900 thermostat or wayne dalton

[TeleFragger]

Ok so I am still eating up batteries in my new thermostat....


soooooo what i need is a hvac guru.... or.....someone with the same setup as me..

who here has a

gas heater and central air conditioning..
their wire running from the hvac to the thermostat only has 4 wires....

and they have the wayne dalton or ca8900 thermostat....


here is what i posted elsewhere on another forum...

Ok so I took a thermostat out..
honeywell... it had 4 wires that go back to my hvac unit..

Red
Green
White
Blue

Thermostat
Red went to R
Green went to G
White went to W
Blue went to Y ( I looked and it is Y on both ends.. 4 conductor wire so they used the blue...)

anyway..
my new thermostat is
intermatic z-wave ca8900

they want me to hookup
Red to R
Green to G
White to W
then they throw a +C to C

well I have the hvac unit hooked up the way my old system was and it works... everything works.. but the C is 24vac to keep the thermostat running.... so instead it is eating up batteries...

what do I do?
just run a new wire back and connect C to the controller board of C????

on the controller board there is everything I listed above with an additional...

C - white wire
then a red wire from that pair goes to Y

so how do I get 24vac to the thermostat???


if you go here
http://www.hometech.com/learn/hvac.html

and goto the section labeled
24VAC Heat/Cool Non-Heat Pump

that is the wires I have now... but need to figure out how to get 24vac to the thermostat so I wont run off of batteries....

I ran a jumper from r to c figuring that if red is voltage it should supply a jump to C... but that didnt work... still killed the batteries in a few days....

anyone know???
thanks
Jeff

 

[drewpeck]

Your red wire is connected to one side of the 24VAC transformer in your system. Connecting the "C" terminal to that line ain't gonna work -- you haven't closed the loop. The "C" terminal MUST be connected to the OTHER side of the transformer secondary coil in order to provide a return path for the current. The "C" designation is for Common -- that other side typically represents the common for the system. If you only have 4 wires, you'll need to add another line from the transformer in your system to the C terminal on your CA8900. Make sure you understand which wires are coming out of that transformer -- and don't confuse the primary with the secondary, unless you like pyrotechnics. Use a multimeter to double check.

 

[TeleFragger]

Your red wire is connected to one side of the 24VAC transformer in your system. Connecting the "C" terminal to that line ain't gonna work -- you haven't closed the loop. The "C" terminal MUST be connected to the OTHER side of the transformer secondary coil in order to provide a return path for the current. The "C" designation is for Common -- that other side typically represents the common for the system. If you only have 4 wires, you'll need to add another line from the transformer in your system to the C terminal on your CA8900. Make sure you understand which wires are coming out of that transformer -- and don't confuse the primary with the secondary, unless you like pyrotechnics. Use a multimeter to double check.

thanks... yeah got it working... had to run a 5 wire back to the heater... once I did that... connect to C on both ends and viola... no more eating up batteries....

 

[Globezen]

thanks... yeah got it working... had to run a 5 wire back to the heater... once I did that... connect to C on both ends and viola... no more eating up batteries....

I had the same issues - using Intermatics CA8900; Batteries were running out almost daily. I connected Blue wire (common) to C on the thermostat but then I had to go back on the furnace, connect the Blue/Common wire to 'C' on the furnace curcuit board and it then Worked for me too...Thanks for the raising this question. It helped today...