I wouldn't run the alarm system from the thermostat low voltage feed. I don't know why security systems have moved from 24 volts to 5, 10, 14, 16 volts but a 24 volt AC feed is likely fraught with problems.

I don't know which system you have but the thermostat runs off 24 volts AC. If your alarm panel has a + and - terminals, I'd double check that it is also AC and not DC.

Thanks for your quick response. In small writing on the inside cover of the alarm control panel it says "Do not connect AC power to a receptacle controlled by a switch". I assume that means not to connect to it an AC feed.

Anything for HVAC must be on a dedicated circuit, no taping in.

Thanks for your quick response. In small writing on the inside cover of the alarm control panel it says "Do not connect AC power to a receptacle controlled by a switch". I assume that means not to connect to it an AC feed.

Well, I don't know. They may just be saying don't plug the system transformer into a switched outlet.

1. Don't run your alarm control panel off the 24 volt AC furnace power. Since your thermostat cable has 3 unused wires, use those wires to get the needed power from the utility room up to the thermostat to power your alarm panel. Mount a DC power supply of sufficient power near the furnace, connect the power into two of those unused thermostat wires and you now have power available up at the thermostat to run your alarm panel.

2. I would use black and orange wires or brown and orange wires for the DC power, your choice.

3. You don't need a licensed electrician, this is low voltage so you can DIY. Just keep the DC power separated from the thermostat power.

The 2gig alarm panel uses a 14 V DC power supply. If you connect it to the 24 AC supply of the thermostat you likely fry the electronics. Here is the 2gig-AC1-Switching-Power-Supply which should work with you panel. You can plug the power supply to into a 120 V outlet. Don't use an outlet that is controlled by a wall switch. Someone might flip the switch and your alarm won't have power.

Ross is incorrect. Just because it's lower voltage doesn't much change the rules. If you're in a single-family house in most places you can DUI your stuff even at 120V. If you're not in a single-family, you have no business running or changing ANY wiring.

You need to check carefully how much current your alarm needs. First, you don't want to exceed the ampacity of the 20G or whatever thermostat wire. You can heat up and start a fire with 12V DC just as well as with 120V.

Second, you need the amperage compute the voltage drop when sizing your power supply. Your going to lose voltage over longer distances of thinner wire.

OK, here's the deal. Your 2Gig security system is powered by a 14 volt DC power supply. Get the proper power supply for your system. Plug it into an unswitched power outlet. The recommended wire is 18 gauge solid core. Most thermostat wire is 20 or 22 gauge solid core wire, so this is pushing it.

Thanks to all. I have the power supply but was trying to get a cleaner look for the panel and mount it to the wall without wires being visible.

You can mount the keypad above a convenient wall outlet. Fish the wire inside the wall, down from the keypad to the outlet and out the bottom. Attach the wire to the power supply, put the outlet cove in place, insert the power supply and screw it into the center of the outlet. This is the way the pros do it for a clean look - no wires showing, just a wall wart in the socket.

You are calling for trouble if you follow your idea. Though the idea by sktn77a is a practical one with the positive and wanted results.