15
votes
Do I need a junction box for thermostat wire splices?
A junction box is not required for low voltage.
However, using a junction box may make the splice more reliable in the long term, by protecting it and securing the wires so it's not stressed.
- 203k
11
votes
New Thermostat displaying inaccurate for outdoor temperature sensor
After inspection of the thermocouple located just below and outside the heat pump I discovered the tape used to hold the sensor to the heat pump was caked with light dirt and mud. I removed the ...
- 485
8
votes
Accepted
Will this thermostat work for my wiring?
That thermostat will not work. The terminal labels and type indicate small gauge low voltage wiring. You have line-level (high voltage) wiring. Look for a "line voltage" thermostat.
- 130k
4
votes
Thermostat relocation
What you need is a thermostat remote sensor.
You will also need a thermostat that can receive the signal from a remote sensor. When programed properly, the HVAC unit will react to only the signal ...
- 25.1k
4
votes
Accepted
Do I need a junction box for thermostat wire splices?
The NEC says:
90.3 Code Arrangement. This Code is divided into the introduction and nine chapters, as shown in Figure 90.3. Chapters 1, 2, 3, and 4
apply generally. Chapters 5, 6, and 7 apply to ...
- 16.6k
3
votes
Accepted
Help wiring thermostat
You will need a connector that can take more wires for the white wires (L2). The red wire from the new thermostat goes to the white L2 wires. The two black wires go to the black wires that are ...
- 9,302
3
votes
2 thermostats daisy chained on 12g wire
A 20A 240V circuit can provide 4,800W of power. However for continuous use such as heaters it is derated to 3,840W (80 %).
With 2 x 1,500W = 3,000W that leaves 840W available. A 700W heater fits, with ...
2
votes
Is there a limit to how far/long you can run thermostat wire before it loses it's ability to work?
TL;DR No problem
There is a limit. Everything has a limit. But 40 feet should not be a problem. Even 100 feet really isn't an issue.
Low-voltage thermostat wires (and "Google thermostat" ...
2
votes
What smart thermostats is compatible with live wire Fan coil system
To the best of my knowledge there are no line voltage smart thermostats. I've seen a lot of cheap foreign models advertised as line voltage, but the reviews always say otherwise. I can say, with ...
- 96
2
votes
Where to "splice in" 24v C wire with no control board for new smart thermostat
The wiring diagram indicates that there's a yellow wire coming off the transformer, going into a wire nut with a blue wire. That's your C. I've highlighted it in the image below.
- 28k
2
votes
Replacing two adjacent thermostats with one
There are two different possibilities here:
Same Circuit
If the heaters are currently on the same circuit (i.e., turning off one double-breaker turns off both heaters) then this is easy. If you can ...
2
votes
Will three baseboard heaters overload my wiring or thermostat?
Yes, 3 1500W heaters will overload both your 3500W thermostat and your 20A 240V circuit.
You either need an additional double pole circuit and a second thermostat, or a 30A breaker and 10 gauge (...
- 203k
1
vote
Installing smart thermostat but can’t fish new wire
If your problem is the most common one, lack of a C wire, the easiest alternative is to use a C-wire adapter. You install a pair of boxes, one at the furnace and one at the thermostat, which ...
- 34.4k
1
vote
AC constantly running and overcooling my house
To summarize the stated problem:
Thermostat set to COOL - 73F.
House temperature is significantly lower than 73F.
Air conditioning appears to still be running.
There are two very different possible ...
1
vote
Accepted
Replace under floor heating thermostat
If I'm understanding your diagram, it's the other way around. Your existing thermostat has only a NO dry contact connection. Your new one has both NC and NO, so you ignore the NC contact. NO is short ...
- 9,302
1
vote
Trane XR95 No power (2 volts) to Thermostat
The box on the floor is likely a condensate pump. Temporarily, yes, you could bypass it to see whether the furnace runs again.
The Trane XR95 is a condensing furnace. This means that it extracts so ...
- 28k
1
vote
Accepted
How to wire ecobee thermostat to central heat pump (two wires only)
You'll need to pull a new cable
Your old wired controller communicated with the indoor unit over a proprietary two-wire interface. As a result, you'll need to completely redo the wiring in order to ...
- 81.8k
1
vote
Do they make a 120 volt programmable thermostat?
If they don't, a 24V thermostat, a 24V programmable relay, a 24V transformer, and a box add up to the same thing. Which is how your 24V thermostat controls your 120V household heating system, after ...
- 27.7k
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