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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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Thermostat wiring with external transformer

So I am trying to wire a Honeywell lyric thermostat and I tried following videos but got a little stuck. So I have wires R, W ,Y , G coming to my original thermostat. I bought an 24V external ...
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Should I connect the white wire to the aux connection on my new thermostat?

I changed my old thermostat to a honeywell rth3100c. I was instructed to attach the white wire to the aux. connection. I do not have a heat pump. all electric system. Is this correct and if so for ...
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Putting a WiFi thermostat on a Milli volt system control of a fireplace.

I under stand that it can be done using a transformer and a relay along with a WiFi thermostat. I want to keep the present Milli volt thermostat functioning in case I loose electrical power and I ...
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Why does my non-vented gas fireplace turn off after a few minutes?

I have a non vented gas fireplace, brand new, it has a screen on the front and logs. The pilot light is strong and stays lit, however the main flames turn off after a few minutes even when the ...
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Honeywell TH6110D1005 Thermostat keeps resetting itself

I have a Honeywell TH6110D1005 thermostat. I do not use the program mode, I keep my temp set to 71° at all times when it is on the Cool setting. Sometimes, it resets itself to 65° for no reason ...
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How to wire new Honeywell smart wifi thermostate( RTH9590WF) to replace older Honeywell thermostat using only 3 wires

Old thermostat was only using 3 wires, connected to W, G and R-Rc jumper. no C wire. Does have extra wires not being used at each end. Big question is what to I connect to at the furnace for a power ...
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Why Does My Heil Furnace Start When It Should Be Off?

My Heil furnace starts with the thermostat set to off. I disconnected the thermostat wires at the thermostat and it still starts randomly. I disconnected the heating wire at the board and it still ...
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C Wire in HVAC Unit

I am looking to install a new style thermostat in my apartment and it requires a C wire. I do have an extra wire run from my HVAC unit to where my thermostat is. But when tracing it back to my HVAC ...
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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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Nest thermostat - combi boiler and UFH set up question

We recently had some work done, a new open plan room, a new boiler and underfloor heating (UFH) put in. We had some confusion, a lot of which comes from not having a basic understanding of how the ...
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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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AC Compressor outside is not running with new thermostat

my old thermostat stopped working, so I purchased a new one to replace that. The old one was powered by two AA batteries. A green wire connected to G, a white wire connected to W, a blue wire ...
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Changing Trane Baystat240a to another thermostat

I want to change my current thermostat to a programmable electric one (no batteries). Could someone verify if it does have a common wire and if all wiring could fit modern thermostats? Looking at the ...
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How can I tell if C wire is active and connected to Thermostats?

We are trying to install a smart thermostat (Ecobee 3) so we are in need of a C wire from our boiler. We see a green wire in the wall, but it's not connected to our thermostat currently since it ...
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Thermostat needs to be set very high to work

Our home thermostat is behaving strangely. Let say it shows that the current room temperature is 60F. If we set it to 63F it will start the Fan (ventilation) but will not actually start the heating so ...
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Keep finding thermostat on heat

On multiple occasions now, I have noticed odd things going on with my HVAC system, only to go to the thermostat and find that it has been set to heat! This happened once in the middle of summer, when ...
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Thermostat replacement

My old thermostat is a carrier t-stat and has a jumper wire between o/w2* and L I am upgrading to a honeywell wifi t-stat, should I install the same jumper wire on the new thermostat? I have an ...
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Master-Slave type Thermostat?

I have 4 thermostats located in four different zones and a separate AC thermostat. I want to get some programmable thermostats for each location. I could buy 4 individual programmable thermostats ...
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why does my heat pump wiring diagram show 7 wires going to the thermostat but the thermostat only says it needs 5?

Here is a link to the wiring diagram for my heat pump. The thermostat that I am planning on buying has the following terminals C, G, Y, O/B, RC, R, Aux, E, and L. The instructions say to jump the RC ...
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982 views

How can I add a C-wire to a Venstar T5800 thermostat?

I am trying to replace my existing thermostat. My old thermostat has: Rh, W (coming from the heating unit). Rc, Y, G (coming from the AC unit). On the Venstar T5800, I can map as follows: Rh+Rc -...
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Why isn't water running through our radiators?

We had a plumber in today to bleed our rads. He also changed the batteries on the thermostat and fiddled around with the boiler. Since he left the temperature has dropped dramatically and he's refused ...
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1answer
207 views

Furnace came on when it shouldn't have

I happened to be down in the basement a short while ago and heard the furnace turn on and off after just a few seconds. About a minute later it came on and this time it stayed on for about 15 seconds ...
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I changed my thermostat, not my heat does not work… help!

I know I made a mistake, but here's the storey. When I was hooking up the new thermostat I did it with live wires, and I used metal pliers (metal touching metal). The wires may have also touched ...
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I want fan ON 24/7, NEVER turn off. How to force fan on even when furnace turns on?

I HATE that EVERY time the furnace toggles on, it turns OFF my fan and no fan for about 3 minutes. EVERY NIGHT this WAKES ME UP throughout the night. It is so bad that I decided to turn the HEAT OFF ...