Replacing 4-Wire Thermostat with Green, Red, Blue & White Wires

[hamada]

I just purchased the wired version of the Insteon Thermostat and have an installation question. My existing wiring is only four wires: green, red, blue and white. The current thermostat is Indiglo 43154A and the HVAC is Trane 4TCY-IG-8 Single packaged, cooling with electric heat.

I attached a picture of the current wiring and am confused about how to wire existing wires to the new Insteon thermostat. The existing thermostat has a red jumper wire on RC and RH and a red wire going into RC.

Here is the current wiring scheme:

Green Wire --> G
Red Wire --> RC (RC and RH using a red jumper)
Blue Wire --> Y/O
White Wire --> W/B
Nothing --> Y1

I also understand that there is an accessory on smarthome.com to convert 4 wire systems into 5 without having to run a wire from the system board. If that is required, please let me know and how to wire it.

I tested with a voltage tester and G RC and RH blink / beep on the wire tester. RC and RH seem to have more juice. Does that mean I have a C Wire?

Thanks in advance.

[stusviews]

You do not have a C wire. What you need is an
Add-a-Wire Kit.

[hamada]

You do not have a C wire. What you need is an
Add-a-Wire Kit.

That's what I thought. Thanks for the info and the prompt reply. I will buy it today and get back on the forum with any further questions.