Conduit for thermostat wiring?

[SQLit]

Low voltage wire does not need protection inside a wall.

[Stubby]

Does the NEC require armored cable or conduit for a new thermostat run? I have to go through a wall into the utility room and about 3 feet horizontally to get to a box where the zone valve and thermostat wire meet.

[Ben Bee]

replying to SQLit, Ben Bee wrote: Can you please cite any codes that say this?

[trader_4]

You can go look it up in the NEC. Or ask yourself if you've ever seen a low voltage thermostat installed that used conduit or armored cable. I've seen plenty, including new construction, never once a conduit or armored cable. We don't even typically use that for 120/240V AC.

[gfretwell]

It is pretty common in commercial and they might require it in a mobbed up union city like Chicago or New York for residential. Chicago and New York traditionally required a metal wiring method for all residential wiring but I hear they may have softened up a bit. Chicago wanted EMT and New York leaned more towards AC cable.

[Clare Snyder]

On line voltage thermostats it's not uncommon - but you don't see it on 24 volt stuff.

[gfretwell]

We ran cat 5 and coax in conduit in commercial.

[Clare Snyder]

We did inside steel stud walls

[gfretwell]

I haven't seen wood in a commercial building in 40-50 years and it is used in most new residential down here. The only wood in the houses my wife built was in the load bearing walls of a 2 story and there were not that many 2 stories. In commercial the BICSI standard is 3/4 EMT for video, voice and data. The fire code calls for a metal wiring method for fire alarm and control wiring, typically MC cable.

[gregz]

The units that use switching motors might help noise issue with conduit. My thermostat was radiating lots of noise. I cut down at source inside furnace using filters, even on AC feed. I still have some noise.

Greg