Tagged Questions

1
vote
1answer
24 views

thermostat c wire question [duplicate]

I am looking to install a new thermostat that will require a C wire. I have a single stage A/C unit and my current thermostat has Rc, G, and Y wires. There is also an unused blue wire which I traced ...
0
votes
1answer
78 views

Why isn't my thermostat clicking on/off automatically?

My thermostat is not clicking on/off automatically, I have called my landlord and they replaced a very old one with a brand new one and it is still not clicking on off automatically, but will ...
0
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1answer
42 views

Why isn't my thermostat working?

I have an old Lennox (gas heat only) thermostat. There are 3 wires coming from the wall. Black, yellow and a light blue color (could be a faded green or an old dirty white). The thermostat wouldn't ...
1
vote
1answer
126 views

Can you terminate more than one common on the furnace C terminal?

TL;DR: Can you terminate more than one common on the furnace C terminal? Background: I've linked a diagram of how my non-programmable thermostat is currently hooked up. I want to replace it with a ...
0
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1answer
157 views

How can I use a separate transformer to provide a C wire to my thermostat?

I Purchased the Honeywell WiFi Prog Thermostat to replace my Round Digital Honeywell Thermostat. I have separate Heating and Cooling (Heating is a Weil McLain Boiler for Hot water baseboard and Hot ...
3
votes
1answer
1k views

Convert line voltage heating system to use low voltage thermostats

I currently have two line voltage ceiling radiant heating systems in my condo each with their own DPST thermostat. I'd like to use low voltage thermostats such as the nest. I found this ...
2
votes
1answer
2k views

How can I add a “C” common wire to this system?

I would like to add a "C" / Common wire hookup to my hvac system and get a fancy new thermostat. I've read Options for adding "C" wire to thermostat and still have some questions. First of ...
1
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4answers
512 views

Is it alright that I did not turn off the power while installing my thermostat?

I just installed the Nest thermostat, I forgot to turn the breaker off everything seems to be working fine. Is it safe to assume it is ok?
4
votes
4answers
415 views

Risk from installing a “Nest” thermometer without shutting off home power?

I'm trying to install a new Nest-brand thermometer in my parents' house (unscrewing a thermometer from the wall and screwing on the new one. The first instruction in the manual is to shut off power ...
3
votes
2answers
658 views

Trying to wire a 220v line-voltage thermostat

I am trying to replace my old 220v line-voltage thermostat with a modern version. The problem is that after wiring the new version in like the old it doesn't work. I have (2) 12-2 wires coming out of ...
4
votes
1answer
1k views

Replace two-wire thermostat

I'm replacing an old mercury thermostat with a digital one. The new unit has 7-8 connections (labeled w1,wh,r1,rh,y,c, etc.) and a bunch of instructions about how to connect similarly labeled ...
4
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2answers
6k views

What should I use to wire a 220v electric baseboard heater and thermostat? 12/2 or 12/3

When I bought my baseboard heaters, thermostats and 220v breakers I was advised to get 12/3 wire. When I attempted to install the heaters I found that the thermostats, heaters, and even breakers have ...
0
votes
1answer
276 views

Does a fridge thermostat need a ground connection?

I've recently replaced the thermostat in my fridge with a new unit with a much higher temperature range (this unit specifically). The unit I took out had a ground connector & the original wiring ...
3
votes
3answers
2k views

Why won't my AC system turn off after I flipped the breaker?

We've got a central cooling air conditioner that was installed in 1984 with a thermostat from that same year. We are replacing the thermostat with a new programmable one (which has a 100% ...
3
votes
1answer
113 views

How come the temperature is sometimes not maintained?

First let me come right out and say that I am a software guy and this seems like a hardware problem, so I already feel out of my league. That said, here's the deal: Background: I have two-zone "hot ...