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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.

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2answers
188 views

Lennox G23Q3/4-100-2 And Ecobee4

**Pictures attached to go along with my rambling explanation I have my Lennox G23Q3/4-100-2 natural gas furnace and my central air system that has been working since 1995 on a basic programmable ...
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1answer
38 views

Why is my fan continuously running when A/C is selected?

I bought a home with a honeywell TB8220U1003 thermostat that automatically turns heat on and off with no issues if I have the setting (switch) on my furnace set to heat. In order for my cool to be ...
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1answer
39 views

Furnace Connect G Wire

I have a dual energy electric/oil furnace that is wired to a thermostat with 2 wires R and W. I don't have any AC. Inside the furnace there is a switch relay to control the fan but it is not connected ...
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0answers
14 views

Lennox Furnace Blower not working on AC In On or Auto

Please Help! I have a Lennox Furnace Model G60uhv(X) after years of working fine I switched the thermostat to AC and it failed to start the cooling cycle. I suspect some sort of problem with the ...
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2answers
432 views

Temperature of water in the shower fluctuates - will a cheap thermostatic tap help?

I recently moved to an apartment where temperature of water in the shower fluctuates and we called for a plumber. He either cleaned up or replaced one part (I think it was the mixer - nothing visually ...
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1answer
25 views

Can I safely jumper between either G or Y and RC at thermostat panel to troubleshoot AC problem?

I'm trying to troubleshoot a non-functioning AC. The fan does not come on and there is no cool air/condenser does not run. My thermostat is a Braeburn. Three things I'd like to try for ...
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1answer
39 views

Furnace with no “C” connection

I have a mobile home furnace. This furnace only has a 4 wire connection terminal, G,W,R,Y. I also have a condensing unit outside with the 24 volt 2 wires coming to the furnace. I know I connect one to ...
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0answers
34 views

Thermostat wiring for ac

I recently installed a nest thermostat for our AC system. Unfortunately I was short sighted and just assumed all the wires were the color I needed. Since installing the thermostat our system won’t ...
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2answers
337 views

Old furnace with no “C” terminal for wifi thermostat

I'm new to this forum and was wondering if I could get some help regarding installing a Honeywell WiFi thermostat that requires a "C" terminal. I currently have an older thermostat that has only 4 ...
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1answer
4k views

Honeywell RTH6500 WiFi Thermostat wiring questions for a heat pump

I'm trying to install a new Honeywell RTH6500 thermostat on an old heat pump system that has regular plus emergency heat and the closest matching diagram says to put both the white "W2" wire and black ...
1
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1answer
59 views

How to connect a new C wire

I have a 2 zone, single stage, heat only system with 2 wires running to each thermostat. I'm looking to install 2 Ecobee's; I have a second Honeywell AT72D1683 that I can install if needed and have ...
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1answer
39 views

Is my control board bad?

I have a Goodman evaporator/gas heating unit that runs the central fan motor constantly after it is powered up a couple of seconds. This happens regardless of what wires are hooked to the control ...
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1answer
34 views

Converting I+ I- thermostat to 'standard' wiring

I've been replacing my thermostats with the RadioThermostat CT50, which reports to my home-brew home control/alarm system. I have a 3-year old AireEase 4-ton unit in the shop that has a Comfort Sync ...
4
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1answer
178 views

Is it possible - setting thermostat based on a separate thermometer

I'm looking into building a solar water heater, but I'm wondering, is it possible (and what products should I be looking for) to turn on a pump when the water in the solar heating device is hotter ...
1
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1answer
35 views

Hook up new thermostat

Top brown picture is my old thermostat white is the new one , do I have it wired correct? On out side unit we have replaced motor, fuses, compassator ,cc contactor ,relay . We have a heat pump. But ...
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1answer
664 views

Need help adding a C wire for a wifi thermostat

With the increasing popularity of wifi thermostats I know this question has been asked many times, however I'll ask it again fr my specific situation. How do I add a "C" wire to my existing air ...
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0answers
17 views

Only blows hot air on both modes

I just installed a new Honeywell WiFi thermostat and my heat pump only blows hot air on heat and cool mode.
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1answer
141 views

How should the thermostat wires be connected to my furnace?

I have an Amana AMV90704CXBB furnace, and regular programmable thermostat. I took the furnace apart because I have to wash the blower motor wheel. It was covered in construction dust. In order to ...
2
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1answer
38 views

Do any home thermostats have an adjustable control range?

I am having trouble with AC and need to replace it soon ; so I have been listening to it cycle .I knew it only stayed on a short time but I just found it runs less the 2 minutes ; that is with ...
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0answers
13 views

Heat not kicking on

I live in an apartment with radiator baseboard heating and an old Honeywell round dial thermostat (no external switch). Heat has been working fine all winter. Weather has warmed up past few days- it'...
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1answer
41 views

Finding Common Wire on Laars JVT boiler

Replacing mercury thermostat with wifi. I have just a red and white wire connected to current thermostat and boiler. There is a green present, but it isn't hooked to anything on boiler. So I can ...
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1answer
35 views

C Wire in Air Handler

Can someone please help me find where to connect a C wire for my smart thermostat? Here are some pictures with descriptions. It is difficult to get to the 24v connection in the back. My schematic ...
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2answers
59 views

I have an unused C wire hooked up to thermostat and have no idea where to connect it to the furnace for power

I know this question gets asked all the time but I've spent hours staring at forums as well as my furnace and at this point I'm desperate. I just bought a nest thermostat that needs a C wire ...
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3answers
877 views

How many wires should be in a new thermostat cable?

When roughing in thermostat wire, how many pair wire would you use to cover most thermostats? I'm asking because keep seeing questions about C wire and wifi.
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0answers
16 views

Installed Honeywell R8285A 1048 control center combined with a Honeywell PRO 8000 thermostat

to operate an inline duct fan on a long run to a new addition. Thermostat in the new addition activates fan when the thermostat is set to cooling perfectly. I can use it to manually turn on the fan. ...
0
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1answer
40 views

Temperature monitoring for storage hot water system (RP-2 connection)

My HWS has a secondary outlet connection I don't use, and I'd like to use it to install a thermal probe I can monitor. HWS RP ¾ / 20 temp probe? Does anyone know of a practical way to install a ...
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0answers
27 views

Where to install C wire?

I need to run new thermostat wire since I don't have a C wire to power my smart thermostat, but need some guidance on where to hook it up. I have five wires at my thermostat, two going back to my ...
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2answers
2k views

Why might a thermostat refuse to switch from Heat mode to Cool mode?

I have this Honeywell RTHL2410C programmable thermostat and typical Florida electric AC system. Starting this Spring, it has started behaving strangely when switching from Heat to Cool mode. The ...
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1answer
49 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 ...
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1answer
49 views

Remove switch that controls thermostat

I recently bought a condominium in a large building, built in 2005. It has a single thermostat, and the thermostat works fine. But right next to the thermostat, there is a switch. It looks like an ...
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1answer
380 views

Connect Ecobee3 thermostat - no c wire but c terminal occupied

I am trying to install a new Ecobee3 wi-fi thermostat to replace my old mercury thermostat. When I pull off old thermostat there are only 4 wires (red, white, yellow, green and a blue tied around). ...
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0answers
25 views

Weathertron Xl1200 to Nest Thermostat

We have a Trane Weathertron Xl1200 heating pump with the thermostat pictured below and are trying to replace it with our new Nest thermostat. Our old system has a variable speed air handler and we ...
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2answers
114 views

Misbehaving/inaccurate thermostat?

I have a portable air conditioner/hvac and I'm having issues with it in heating mode. It's actually summer where I live but it was somewhat chilly as a storm passed over so I wanted to test heating on ...
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1answer
24 views

Old furnace with extra wire, but no c terminal Janitrol, 19 year old furnace

I've searched multiple threads regarding this, but I didn't manage to find any that seemed to match my use case. My board doesnt have a C terminal, and it doesn't have the other terminals connect to ...
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1answer
565 views

Wiring a C (common) wire to a Triangle Tube Prestige Excellence 110?

Wiring noob here. Can someone give me step-by-step instructions for where and how I should attach a C (common) wire to a Triangle Tube Prestige Excellence 110 boiler for a ecobee3 thermostat? I think ...
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1answer
59 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.
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1answer
36 views

Complete power loss in over-the-range microwave

The over-the-range microwave in my kitchen (GE, 1500W) has completely lost power. The power loss was intermittent for a day, but then at some point it never came back. I have checked all fuses that I ...
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0answers
46 views

Can I use this White Wire for a thermostat C wire?

An AC-only machine cools a storage facility: no heat. The 30 year old thermostat is to be replaced with a wifi thermostat, which requires a C-wire to power the electronics. There are 4 wires: Red (...
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2answers
2k views

Can I shorten my in floor heating cable?

Just wiring up an in floor heating thermostat. I have two separate two wires going into my flooring as well as another coming from the panel. I am wondering about the two wires going down to the ...
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1answer
173 views

Ecobee3 Setup and furnace only has W G R

My existing thermostat has 4 wires (missing C) so I'm attempting to use the Power Extender Kit (PEK) at the furnace control board. Only problem is, I only have 3 wires that are obviously labelled at ...
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2answers
1k views

Why does hot air from my fan heater stop after 4 to 7 seconds?

Product: Challenge fan heater: model E9907R-N -- 230-240V -- 50 Hz -- 2750-3000W. While off, something fell through the grid. I opened the fan heater to remove it. It now doesn't blow hot air (...
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0answers
31 views

AC unit not turning on

My A/C doesn't come on when I set the temperature on the Braeburn thermostat very low. Also, the recirculation fan doesn't come on when I set the thermostats fan setting to 'on', as though the indoor ...
1
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1answer
26 views

Switching from a Mercury Switch Thermostat to a XT500C Thermostat

I only have a white, red, green and yellow wires, from my old thermostat. I see multiple Red wires... where does a single red wire go... to the R connection...
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0answers
22 views

Ecobee 4 not recognizing PEK

I have four wires going to the thermostat. So I installed the PEK 5 wires out of the PEK to color matching terminals in the furnace block. Going into the PEK were the four wires from the thermostat, R,...
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1answer
101 views

Ecobee3 lite connected to Lennox Pulse G14Q Heat/Air Condition

I have read a similar wifi thermo connection feed here and they had success hooking the C wire to the T terminal on the furnace. I can get power to run the thermo from the T terminal, but when I do, ...
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3answers
79 views

Updating old Lennox thermostat - wiring confusion

I am trying to update my old Lennox thermostat to a Sensi smart thermostat. I checked the compatibility on the Sensi website and it appears to be a match except for this cluster of wires on the left ...
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1answer
2k views

Thermostat won't always start heater on its own

I have a gas furnace that seems to work fine; it keeps the house warm when things are running as expected. Sometimes, however, we'll notice the house is getting cold. The temperature on the ...
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1answer
174 views

Adding a C wire to older 3 wire

How do I use the green wire as a C wire as suggested in most installation instructions for the newer wi-fi thermostats? They all reference terminal strips at the furnace, all I have is the 3 wire ...
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2answers
2k views

Nest thermostat gen 2 won’t turn off furnace

I’m struggling to find a solution for my furnace. It’s an older Lennox furnace and runs fine. The problem I’m having is that it keeps burning up my thermostats and once it does it won’t let the ...
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2answers
683 views

Replacement thermostat wiring

I have an American Standard heat pump AC. I'm replacing a White-Rodgers manual thermostat (where I move a switch from cold to heat) with a Honeywell RTH7600 (which will automatically switch from cold ...