2441th Thermostat wiring

[wingman1]

trying to add a 2441th and need to know how to wire it into my existing system which has a seperate heating and cooling system. 2 wires from the heating system 3 wires from the cooling system.Attach is how the old thermostat is wired. therh8-19-14.jpg

[stusviews]

The 2441TH cannot accommodate two transformers. Select which one transformer you want to use and run a pair of wires between the two. Note which wires are connected to the top two terminals in the diagram and connect those together. Do the same with the bottom pair.

You also need to connect both sides of the transformer to the thermostat. You can use the extra transformer wire for that.

[wingman1]

ok my old thermostat has

RH= red coming from heating system
RC=red coming from A/C
W=white coming from heating system
Y=white coming from A/C
G=green coming from A/C

with the Heating not running and the A/C not running i measure 28.5 volts from RH to W and from RC to Y with the heating running the voltage at RH to W drops to almost 0 indicating the the circuit is closed. Haven't tested the A/C but i am sure it does the same. There is no common wire from either system. Are you saying that i twisted the 2 red wires together (RH+RC) and put on 24R of the 2441th and i would have to have a common wire from each unit and the 2441th would provide 24v to the W or Y and G depending on which system is running?

[stusviews]

No. You cannot use both transformers. Label the wires and remove the thermostat. In all likelihood, you have two thermostat cables. One or both cables may not have all the thermostat wires connected to anything. Describe what you find.

You will also need to describe what you find at the other end of each cable.

[wingman1]

Ok here is what comes from the heating system.
20141208_163408 (640x360).jpg

circled in yellow are the 2 wires going to the thermostat red wire provides 24v
circled in yellow seems to be the 24v hot and common not used

from the A/C unit could get pictures is a red wire 24v white wire return for cool and a green wire for fan
no common wire coming from either.

correct me if i am wrong but should it work if if i bring up the 24v and com from the heating system (marked with red circle) and remove the red wire from the terminal marked in yellow leaving the white in place up to the 2441th
then from the A/C unit remove the red wire 24v and pace on the common bring it down to the common on the 2441th and the 24v would feed to it from the heating system though the 2441th

[stusviews]

How may wires in each cable? What are their colors? You will need at least one more wire in each cable than is being used. What about the A/C transformer, does it have screw terminals so that you can disconnect it?

The heating system does not appear to have terminals, but the fuse may be for the 24VAC.

[wingman1]

RH= red coming from heating system
RC=red coming from A/C
W=white coming from heating system
Y=white coming from A/C
G=green coming from A/C
2 wires from the heat
3 wires from the cool
yes the ac trans can bee disconnected
and the red circle on the pic has 24v side terminals

[stusviews]

If those are the only wires, then you'll need to run a cable between the heating system and the cooling system. You would use the 24VAC from the heating unit to power the cooling unit, bypassing (disconnecting) the cooling unit power supply.

[wingman1]

wiring.jpg
this is what i am looking to do going to tie 24 vac and common at the thermostat to bring it up to the ac unit by running new wire 3 up from the heating unit and 4 up to the ac unit. The ac units transformer will be disconnected.

[stusviews]

That appears correct.

[wingman1]

one more question On the old thermostat when call for heat it would send 24v to the w=white wire on the 2441th does it also send 24v to the w1 and if so it not

[stusviews]

One of the 24VAC-COM pairs is reversed. Based on the top schematic, the top wire from each transformer should be 24VAC and the bottom pair should be COM. Top or bottom, left or right on the actual device has no meaning wrt/wiring.

Reversing the wires at the thermostat will only swap the non-functioning mode from heat to cool.