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Questions tagged [thermostat]

Mechanical or electrical device used to control a heating, ventilation, and air conditioning (HVAC) system, or other temperature reliant system.

2
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1answer
182 views

Where to connect c wire

I’m installing a new WiFi thermostat that needs the c wire. I ended up running new thermostat wires that contained the common wire but now I’m stuck on where to connect it to the furnace. Can ...
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1answer
5k views

Why are the white and orange wires both connected to my thermostat's W terminal?

I wanted to get a programmable thermostat, but when I look at the wiring of the existing thermostat I’m not sure why the white and orange wires are both going to the W terminal. Other thermostat ...
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0answers
83 views

Need pin outs or rear photo of Honeywell RTH9580 thermostat back plate

Does anyone happen to have an uninstalled Honeywell RTH9580 that they could snap a photo of the rear of the circuit board on the mounting plate for me? I don't have a mounting plate, but I do have a ...
2
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1answer
6k views

Ecobee3 not turning on heat, but fan is on

I have an Ecobee3 that has been successfully working (both heat, fan, and AC) for the past 6 months. Recently I was trying to get my humidifier working so I was playing around with some wires, which ...
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1answer
43 views

UV Lamp on heating system?

I have a Honeywell thermostat & keeps on flashing "change UV Lamp" Where would I find the UV lamp installed in the system, & how do I replace it?
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1answer
428 views

C Wire for Thermostat

I am upgrading my thermostat (Have AC & Heat) and found that it doesn't have the "C" wire that I need to power my new thermostat. The furnace does have a terminal for C, but only condensation pump ...
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1answer
266 views

Removing a room stat from central heating (in order to fit Hive)

I'm about to fit a Hive wireless thermostat to my central heating system and have a couple of questions. I need to disconnect the existing room stat - a Horstmann Centaurstat 7 - as this will be ...
2
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1answer
279 views

Installing a Hive Thermostat

I purchased a HIVE thermostat and want some assurance before I go about installing this. First of all i was wondering where to put the receiver as I thought it would just replace one of the ...
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1answer
64 views

Proper placement of thermostat [closed]

I am building a new home and the question of where the thermostat for the upstairs should go has risen. It was originally wired to be place in my daughter's bedroom but I had requested that it be ...
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1answer
158 views

How to connect wifi thermostat with a boiler after cable upgrade?

I have an old battery operated thermostat right now with two wires (18/2) attached to it running to a boiler. No AC, fan, etc.-- just a boiler. I can easily replace the wire with 18/5 one, however I'm ...
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2answers
4k views

Why do I have to tell my Nest thermostat to either cool or heat my house?

I just moved into a house with a Nest thermostat and this is the first time I've ever had a thermostat of any kind (just had window units and radiators for the past 20 years). I don't understand why ...
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3answers
2k views

Circuit to make Nest thermostat think there are separate heating and cooling systems

I have a Nest thermostat that I am trying to wire in a simple but unique configuration. My apartment uses fan coil units for heating and cooling. The building changes over from hot to cold water for ...
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1answer
42 views

My thermostat and heating system was working fine but the batteries read low power

So my Honeywell non WiFi Thermostat was working fine except for the low battery signal in the top right-hand corner. We took the face off of the thermostat of course shutting the Heat and fan off ...
0
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1answer
305 views

Help with smart thermostat wiring

Installing an ecobee4 thermostat. Have a 2 stage furnace with ac. Had a Trane furnace installed couple years ago and just noticed it's jumpered between W1-W2. Old thermostat wire was only 4, ...
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1answer
55 views

Problems with my thermostat

My thermostat will turn on the baseboard electric heater but will keep running till you turn it all the way off.
3
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1answer
702 views

How do I get the Nest Thermostat to warm up my house prior to arrival

I have a Nest Thermostat and live in the UK. I have a radiator based heating system. When I leave the house, some time later the Nest realises this and sets my house to Away. From this point onwards ...
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1answer
218 views

WiFi Thermostat - C Wire

I am trying to install an Ecobee 3 thermostat to replace the upstairs one I have now but the 3rd wire isn't connected to anything on either end. I added the basement thermostat just to complete the ...
0
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2answers
99 views

How can I control my furnace blower independently from the furnace itself?

I have an outdoor wood burner with a water jacket. It has an electric blower that needs to run to get the fire going hot enough to be clean burning. I have a 200 gallon storage tank, and plan to ...
2
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0answers
577 views

Honeywell WiFi thermostat jumper loop separate ac and gas furnace

I need to validate my understanding for the installation of a WiFi thermostat that requires 24volt continuous power to operate in a constant state. I am DIYer who is computer literate. Like a number ...
0
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1answer
229 views

Replacing thermostat on Sanyo mini split

I have an old Sanyo KMH 0922 mini split. The air conditioning seems to work OK. Last winter on heat it was either on or off the thermostat wouldn't control the temperature correctly. This ...
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1answer
708 views

Honeywell thermostat oozing yellow and programing not working

I installed a Honeywell thermostat last year for our boiler and it worked perfectly. This year we were having issues with it not following the program schedule. The thermostat should be sleeping and ...
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0answers
318 views

NEST thermostat for hydronic floor heating: the three wire setup

I'm trying to install a 2nd generation Nest thermostat for my hydronic floors. So it's only meant for heating and not for cooling. Someone else removed the old thermostat a long time ago so I don't ...
0
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1answer
668 views

UK Nest Installation - Underfloor heating including floor temperature sensor/cutoff

I would like to use Google Nest with my underfloor heating system which is under a wooden floor. Other thermostats allow the user of a floor sensor which monitors the surface temperature of the floor ...
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1answer
243 views

Replacing old mechanical line voltage thermostat with Caleo from Casa Connect

------ Update ------ I followed the instructions from Casa: I made A1 go into the new thermostat and then out into the blacks of B1 and C1 (see my diagram of the old setup below). Then I connected A2 ...
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0answers
2k views

Nest thermostat - electrical buzzing/humming noise

I have recently installed two nest thermostats (the black gen 3, and white model E). The system is gas radiator heat wired to the model E via the usual Rh and W wires, and Rh, Rc, Y, G, W wired to the ...
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1answer
1k views

Hooking a wifi thermostat to a 2 wire boiler

I'm in the process of figuring out how to swap my existing thermostat for a new WiFi thermostat. Naturally it's connected to my home's boiler by 2 really old cloth wrapped wires. Examening the wires,...
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1answer
150 views

Installing thermostat but can't disconnect power

I just bought a house, and I'm trying to save some money by doing simple projects, on my own. I just purchased a smart thermostat and I am trying to follow the directions, for installation. The ...
2
votes
1answer
1k views

Wiring Fresh Air Damper to New Ecobee Thermostat

Ok, here's the deal. I currently have a zoned system with a fresh air "ventilator" (actually just a fresh air damper) and I want to install an ecobee thermostat. The can either be 1 wire (requires ...
2
votes
3answers
6k views

Do I have one or two 24V transformers in HVAC control circuit

I have two old thermostats (one for heating, the other for cooling) that I would like to replace with a single Nest E unit. I have central air and gas heating. Cooling thermostat has the following ...
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2answers
2k views

Replacing old for New Honeywell thermostat

Old thermostat had a jumper between RH And RC, iam replacing that with a Honeywell Programmable thermostat, but idk if I should replace this jumper on new ther mostat ? And if so, should I remove ...
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1answer
144 views

VT1001 talking thermostat has started saying “two sixty four”

I have a energy star rated VT1001 talking thermostat installed sometime in the early to mid 2000s. This morning it began to periodicall speak the words “two sixty four” (264). I cannot find anything ...
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1answer
50 views

Can I safely reconnect thermostat wire on furnace controller?

Furnace (oil) wouldn't come on at any setting (fan works). Tried reset button on controller, no noise, nothing. Then noticed the white wire to one of the thermostat terminals was hanging loose, ...
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2answers
1k views

Installing double-pole line-voltage thermostat

I'm trying to replace a mechanical double pole thermostat with a programmable electronic one. Existing setup: The old thermostat model is 859M and it's wiring is pictured below. There's 2 pairs of ...
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1answer
1k views

Locating HVAC Breaker To Replace Thermostat

I'm looking to install a smart thermostat in a single family home built in 1997 (southern California). My issue is that I cant seem to locate the breaker for the HVAC equipment. I was only able to ...
2
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2answers
265 views

Please help me understand my HVAC wiring

I'm trying to replace an old thermostat with a WiFi one that requires a C wire to power it. When I opened the panel on the air handler 1 (where I'd like to connect the thermostat to), there's no wire ...
2
votes
1answer
99 views

New thermostat: How to wire it?

My old air conditioner thermostat broke down, so I bought a new one. But when it arrived, I was horrified to discover that the terminal of the wires were not named the same. Both thermostats have ...
2
votes
1answer
769 views

Using 15-amp thermostat on a 20 amp circuit

I live in Washington state. I have a 20 amp circuit breaker on a circuit that drives two fan-forced heaters, connected through a single line voltage "dumb" thermostat, unknown rating. I would like to ...
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0answers
398 views

Voltage Drop between W1 and Rc wires

I recently converted from Oil to Gas. One of my zones is no longer working post conversion (it was working, then nothing worked, and then after they replaced a defective unit on the boiler it didn't ...
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0answers
32 views

WIFI “C” terminal

I recently purchased a WIFI thermostat that requires the use of the "C" terminal. I do have an extra wire available to use on the C terminal that runs from the wall unit to the furnace. However, ...
0
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1answer
172 views

wobbly thermostat on plaster wall

Just replaced the old honeywell thermostat to a Nest. But the thermostat hole is a bit more emptier than it's supposed to be. Some small rocks fell out. Now the new thermostat is a bit wobbly. I ...
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2answers
377 views

Max Current Supplied by Thermostat Wire

So I want to run a Raspberry Pi 3 off of thermostat wire. My question is, will the thermostat wire supply enough current for the raspberry pi (2.5 amps)?
3
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2answers
290 views

C wire thermostat assistance

I am trying to install a new wifi stat. The wiring seems to all be there but apparently not connected correctly. So far I have tried using the green wire from the furnace, the blue and the white from ...
0
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0answers
450 views

Need help going from single pole to double pole thermostat

I am trying to replace single pole thermostats with double pole in two adjacent rooms. In each outlet there are three black, three red and three grounding wires. When I removed the single pole ...
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1answer
319 views

Is the control wiring for my boiler reversed?

I've been diagramming my boiler wiring so that I can understand it before installing a Tekmar 256 external reset. What's been throwing me for a loop is that it looks as if the 24v common is being fed ...
0
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1answer
642 views

Can I buy a 24v transformer with a dedicated common c-wire feed?

I have an oil furnace that feeds hot water to baseboard in four zones in my house and also to a hot water tank for tap water. There is a 24vac transformer with two output wires that feed power to the ...
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0answers
62 views

Thermostat Wiring [closed]

I am trying to set up a simple thermostat demonstration to very simply show my parents what a internet connected thermostat could do for them! I have a CT110 thermostat and an old computer fan ...
2
votes
3answers
2k views

Removing old thermostat when replacing electric baseboard heaters

We're renovating a 30 year old home in the US and replacing three 240 volt electric baseboard heaters with new, modern heaters. Currently, each of the three 15+ year old heaters are wired into their ...
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0answers
334 views

3 wire heating system, has 3 unused wires with 16v, can any be used as a common wire?

I hopefully have a quick question. I am thinking of getting a Ecobee or Nest smart thermostat, but doing my checks/research before getting one for this house. I rent, so I can only do minimal changes. ...
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1answer
2k views

Where to connect c wire in furnace

I have 5 wires running to the thermostat from the furnace. The blue wire is not connected on either side. I'd like to connect it as my c wire for a smart thermostat. On the furnace I see W R Y G and ...
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1answer
70 views

Looking for combination of temperature sensor and thermostat - any hints?

After reading a lot, I am still very confused... Maybe you could give me some hint? I am looking for: a temperature sensor in my room a thermostat on my radiator It is important to me that these ...