[Tally Wacher]

I'm about to install a Honeywell RTH9580 at my parents' home. They have a Ducane gas furnace (FPP100A5) and Heil condenser. The Tstat that is currently installed is battery operated unit and has a 4 conductor wire running to it. The wires are W, Y, G, and R. The wires from the condenser are hooked up to the C and Y.

My plan is to pull a 5 conductor wire to the new Tstat and use the extra conductor as the C wire and hook it up to the C on the furnace that is also shared with the wire going to the outside condenser.

Anyone see any issues with this plan? Thanks.

 

[beenthere]

Nope, that will work fine.

 

[supers05]

Good luck. Plan is good. Leave the old cable in place, I'd possible, it could be useful later.

Cheers!

 

[roughneck]

Run the largest thermostat wire you can. Never know when you might need an extra conductor, either to fix a problem or install an accessory, and that extra unused wire comes in really handy when it's waiting there for you.

 

[Tally Wacher]

Good luck. Plan is good. Leave the old cable in place, I'd possible, it could be useful later.

Cheers!

Not sure how I would leave the old wire in place. My plan was to tape the new wire to the old and pull through. You guys have convinced me and I will be pulling a 7 conductor wire instead of the 5. Thanks again to all.

 

[roughneck]

Is it loose? Usually the wire is stapled inside the wall and you can't just pull it through.

 

[Tally Wacher]

Is it loose? Usually the wire is stapled inside the wall and you can't just pull it through.

It must be because I can pull about a foot of it out.

 

[yuri]

If the wire is original to the house it should be stapled. If it was replaced when AC was added then it may be loose as someone already fished it with the old 2 wire.

 

[Tally Wacher]

Then I'm in luck, usually all kinds of things go wrong when I do projects

 

[yuri]

Yep. it definitely ain't like watchin the dis Ole House Hour show. They show you a few minutes of what may have taken them hours to do and I am sure they screw up too.:wink2: