Thermostat Wiring Help -- Replacing Honeywell with Insteon 2441TH

[GoodThings2Life]

Greetings! I've just picked up an Insteon Starter Kit along with an Insteon 2441TH thermostat for the holidays, and I'm looking for some assistance getting the thermostat hooked up properly.

My existing Honeywell thermostat is configured as a 4-wire setup, however, the wires running between HVAC and thermostat are a 6-wire cable, meaning 2 wires are NOT in use.

I'm attaching a crude diagram I drew of my current wiring, but here's the explanation:

1a. AC unit has two yellow cables that are capped to a brown cable with RWG wires in it. One yellow is capped to the Red wire, one is capped to the White wire, and the green wire is just coiled around as a spare wire.

1b. The opposite end of that brown cable has the Red wire capped onto the Red wire of the cable running directly to my thermostat. The White wire is connected to the R connector on my heating system logic board. The Green wire is coiled around the cable unused.

1c. There is another brown cable coming from an unknown source with RWG wires. The Red wire is connected to the C connector on my heating logic board. The White wire is connected to the YELLOW connector on the heating board. The green wire is not used.

2a. The brown cable that runs between the heating logic board and the thermostat is connected as follows:

2b. Red wire is spliced with the red wire coming from AC unit and goes to the thermostat (RC connector).

2c. WYG wires are respectively color matched to their appropriate colored connectors on the heating board AND the thermostat... ie. White to White, Yellow to Yellow, Green to Green.

3. On the thermostat, there is a jumper between the RC and RH connectors.

4. On both ends of the cable between heating board and thermostat, I have blue and brown wires that are unused.


My question is this-- what do I need to do to reconfigure these for the Insteon thermostat? Right now, I'm assuming I could use the Blue wire to connect to something on heat side and use it as the C wire, but I'm new to this whole thing and not familiar with this type of wiring, so just looking for some guidance.

On the Insteon thermostat, my assumption is that the WYG wires connect to their respective Stage 1 connectors, and even though the RC/RH wires are jumpered today on the RC connector, I'm assuming it should be connected to 24RH on the Insteon and the new C wire connects to the 24V COM connector.


On a side note, I'm curious to understand... why doesn't the jumper connecting RC/RH on 4-wire thermostat also appropriately serve the same connectors on the 5-wire Insteon thermostat?

[stusviews]

I'm not sure that everything is spliced together as you describe, some of the wiring makes sense, some doesn't. In any case, the spare blue wire between the control panel and thermostat should be connected as the common wire (C) to power the Insteon thermostat.

Rc and Rh are meant for a system that has separate power supplies for each heating and cooling. Usually, there is only one power supply. In that situation the Rc and Rh are jumpered. The Insteon thermostat is designed for only one power supply (which is what you have), so there is no need for separate terminals.

In general, R is one side of power (like the line) and C is the other side (like the neutral). W is the heat connection, Y is for cooling and G controls the fan which is used for both heating and cooling.

[Danowe36]

i don,t have a insteon i have a nest but on most thermostat that brown wire should not be there. all you should need is 5 wires one for cooling 1 for heating 1 for fan and 1 for the thermostat to keep memory or display. the 5th one is common. so remove that ? wire. also your ac will not work you need the yellow and a common 2 wires like the diagram will not work. if I were you just match c on thermostat to c on furnace and so on. there should only be the one jumper that came with the thermostat.

so here is what I see wrong is the yellow should be on the yellow the red should be on the red. take a blue wire and put on c on thermostat and furnace. put the ac on yellow with other yellow and other wire on c. that should do it.

[stusviews]

There are general standards for thermostat wiring, but there is no requirement that they be adhered to as there is for house wiring. In fact, it's not unusual to find the colors are different than the so called standard, primarily because different components of an HVAC system require only 2 or 3 conductors and 2 or 3 conductor thermostat wire is only available with certain colors that may not conform to what it's being used for.

That's also why the Insteon thermostats include labels that can be attached to each wire. What is (somewhat) consistent is the markings on the devices themselves, for example, the thermostat, panels, zone control boards, dampers, etc.

[Sunflower316]

I am not sure it we have something hooked up wrong but the heat pump is the only thing working. The furnace is the blower only and the house feels cold! Is there an emergency switch I am missing? Maybe this is only for warmer climates where you only have the heat pump.

[stusviews]

I am not sure it we have something hooked up wrong but the heat pump is the only thing working. The furnace is the blower only and the house feels cold! Is there an emergency switch I am missing? Maybe this is only for warmer climates where you only have the heat pump.

What did you replace? What was each color wire connected to on the original thermostat? What is each wire connected to now? Note: Colors are not always standard. Did you label the wires?