Questions tagged [thermostat]

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

Filter by
Sorted by
Tagged with
2
votes
0answers
40 views

HVAC is heating when thermostat is off

I seem to have a problem with my thermostat. I have tested the wiring of my HVAC system by wire nutting the the power (R, red wire) to the AC (Y, black wire), heat (W, white wire), and fan (G, green ...
2
votes
1answer
75 views

Is this wiring dangerous? Smart Thermostat C-wire AC adapter twisted together

Is this wiring scenario dangerous? Is it likely produce sparks or damage my HVAC system? Please read the description and see the image below. Description I didn't have a C-wire for my Emerson Sensi ...
0
votes
1answer
29 views

Air Conditioning Thermostat Wiring

A set of three air-conditioners cool a storage building in an American sub-tropical environment. There is no heat: AC only. Cooling is signaled by switching the RED (24V) to: Yellow wire (cooling ...
4
votes
4answers
4k views

Connection for C wire on Mastertrol Mark V zone control panel

I have spent hours searching the web for information on this 20+ year old zone control panel, which supports 3 zones of Heat and A/C. The thermostat I'm replacing (on Zone 3) connects to T4/T5/T6 as ...
0
votes
1answer
2k views

Honeywell Mercury Themostat 3 Wire, replace with Digital/Programmable?

Have an old Honeywell thermostat (house is 17 years old). Wondering if I can replace it with a newer Digital or Programmable one? Here are some pictures of it.
0
votes
1answer
2k views

C wire - thermostat - not providing power

I'm replacing my old Honeywell thermostat with a new Wifi thermostat. My old/current one is battery powered and doesn't use the C wire. I found the C wire behind the plate. I connected the c wire to ...
0
votes
1answer
44 views

Can an SPST switch be used instead of a thermostat for a gas stove?

We have a gas stove that can be either on or off. It has two wires going to a thermostat that has more capability than the stove, such as control of non-existent air conditioning and fan. The wires ...
1
vote
1answer
256 views

Can't get wifi thermostat to work with gas boiler

I bought a Sensi WiFi thermostat and I have been trying to install it. I can't quite figure out how this wiring should work. Here is a link to pictures of the boiler and the current thermostat. The ...
0
votes
1answer
64 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 ...
1
vote
1answer
79 views

Swapping to Hive thermostat. 4 wire communicator has 2 wires per post

I'd previously asked if I could swap my wires from the 4 wire communicator to the larger board and was told I could. I finally found time to do it. However, as I was preparing to move the wires, I ...
0
votes
0answers
25 views

My thermostat will not start my air conditioner

I remember the same thing last summer where occasionally it would take a number of hours for the ac to kick on after I switched to cool and the temperature was above the threshold. The funny thing is ...
1
vote
1answer
107 views

Wiring for 2-stage thermostat and 2-stage furnace with single stage cooling

I got my furnace and A/C unit replaced last summer. The new furnace has 2-stage heating, the A/C unit is single stage. The installers put in a single stage thermostat, so as far as I could tell it was ...
0
votes
1answer
4k views

Where to connect my “c” wire on the boiler side. Weil mclain gas boiler

Im just curious if the “c” terminal on the plug in relay is where im suppose to connect my “c” wire on the boiler side. I have 18/5 wire ran already. Just need to find out where to terminate. To the ...
0
votes
0answers
12 views

Heater does not start without a power reset

I have a Bonaire MB3-20I and it won't turn on unless I go in the roof and turn the socket off and then on again. When this is done, it stays on for as long as needed, but when we turn the heating off ...
4
votes
2answers
18k views

Can I use the T terminal in my furnace as the C for a Wifi Thermostat?

I've read many posts on this, and believe I know what to do, but want to make sure. My furnace (a Lennox G14 Series) does not have a C terminal which needs to be connected to the C terminal in my new ...
1
vote
0answers
20 views

Programmable Thermostat wiring Question

Existing thermostat is a Honeywell and has a separate connections for Aux (white wire) and E (Emergency black wire) The proposed Honeywell T'stat only has a single terminal labeled "Aux E". ...
0
votes
1answer
59 views

Main burner in NG fireplace goes out

What could be the reason of main burner going out intermittently. The pilot stays on. The voltage of the thermopile is 638mv when burner is off. The thermostat is a manual heat only. When I short out ...
0
votes
1answer
155 views

how to connect C wire for ecobee lite to Weil-McLain EG Series-5 gas steam boiler

I want to upgrade from a battery powered Honeywell thermostat to an ecobee3 lite. This is for heat only. My current Honeywell has two wires: Red and White. Missing is the C cable. There are enough ...
1
vote
1answer
133 views

Old thermostat to Hive thermostat

My wife decided we needed a smart thermostat... which means I need to install said thermostat... Currently a Bryant Evolution series is mounted. She purchased the Hive with Hub when it was on sale. ...
0
votes
1answer
42 views

multiple thermostat boiler connection

I have a boiler system with thermostats and valves for three floors. before i changed the boiler what ever thermostat called for heat worked for that floor. Now all thermostats have to be on or ...
2
votes
1answer
47 views

Thermostat not getting power and won't turn on fan or AC. Does have power with batteries, still no cooling

So first things first, I live in a condo. I don't have a lot of easy access to my AC (and I would imagine my furnace? I'm only guessing where that is though it might be near the water heater instead). ...
3
votes
0answers
52 views

Can someone assess my original thermostat's wiring setup?

This is a new world for me, I haven't messed with circuits since physics 101. When I watched a quick youtube tutorial on setting up my Nest E, I thought it'd be a simple "move wire in old C, to new C ...
4
votes
2answers
2k views

How do I make a 110V fan turn on when the thermostat turns the AC on?

I have installed a new a/c with thermostat...easy enough, but thought to add a fan to the mix. Basically, I'd like to add a fan to increase ventilation into a second room that would turn on whenever ...
1
vote
1answer
59 views

Replacing old 3-wire line voltage single-pole thermostat with a 2-wire one

I'm trying to replace an old Mears M21 SP thermostat controlling the baseboard heater with a new one (Honeywell RLV3120A to be specific). Problem is, the old thermostat has 3 wires (Black, Red, and ...
0
votes
2answers
535 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 ...
0
votes
2answers
404 views

Connect Wifi Thermostat to Goodman GMP050-3?

I'm trying to connect up a wifi thermostat to Goodman furnace, specifically the GMP050-3. I've done some reading on this but I'm still not quite sure how to go about it. Specifically, I'm not sure ...
0
votes
0answers
77 views

Rewiring for Nest Thermostat - Current ABCD Configuration Carrier

So I would like to use a Nest thermostat on my carrier system. I have the ABCD wiring configuration from current thermostat to the board on the furnace. On the attached image, you'll see three brown ...
1
vote
1answer
73 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 ...
1
vote
1answer
133 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 ...
2
votes
2answers
3k 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 ...
1
vote
0answers
80 views

Nest Thermostat E wiring with a C-wire adapter

I wanted to get a Nest Thermostat E, but my current thermostat doesn't have a C wire. From what I read online, it's better to use a C wire, so I was considering adding a Venstar Acc0410 adapter. ...
2
votes
0answers
429 views

Thermostat not getting power (Nest E74)

I replaced an old Honeywell thermostat about a month ago with a Nest thermostat. Friday Nest started displaying an E74 error. I have two furnaces and two outdoor units, one for upstairs and for ...
0
votes
0answers
27 views

central heating comes on at night

we have had this problem for over a year on & off, we have an ideal logic+ 30w combi boiler 8 years old, in fairness has been great , but the central heating sometimes comes on in the night (full ...
3
votes
1answer
70 views

Can I Effectively Jump my Furnace Wiring for A Long Time Safely

So I live in an rental with a forced air furnace. The thermostat that controls it is an old honey well that uses ancient analog components. It works well during the winter for heating, but ...
1
vote
0answers
25 views

Upstairs is getting frigid at night during cool nights

I have a dual zone Lennox system, and it cools well, but for the past few weeks it seems to run away at random cooling the upstairs to several degrees lower than requested. We have EcoBee thermostats ...
1
vote
0answers
54 views

C Wire doesn’t work

Trying to swap an old Honeywell thermostat for new with Wi-Fi. Old thermostat doesn’t need C wire, but I have an unused blue wire in the wall. I installed the new thermostat correctly with the C wire, ...
3
votes
2answers
56 views

Help connecting unused C wire for Smart Thermostat

Looking to connect a newer WiFi thermostat which requires the connection of a c wire. My old thermostat didn’t use a c wire however there is a c wire present in the bundle of wires ( unconnected at ...
1
vote
1answer
121 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 ...
2
votes
2answers
31k views

What could be damaged if I shorted the R wire to the C wire at my thermostat?

OK... so in trying to install a thermostat (and testing to see if the old thermostat was bad) I inadvertently jumped the R and C... (I actually jumped the R and G terminals but the G terminal was ...
1
vote
0answers
33 views

Are 8-Zone Wiring Centers Compatible With Smart Thermostats?

I'm looking at various wiring centers for gas boiler heating and I'm wondering if they're compatible with the major smart thermostats, such as Nest, Hive, and Honeywell. Wiring Centers: Reliance:...
1
vote
1answer
44 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...
1
vote
2answers
2k 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 (...
2
votes
2answers
2k views

Can I install two thermostats on one furnace/act unit? I will be using one in living room, the other in a hallway

The reason is that there is a gas fireplace(stove) in the living room that has the pilot on all year. Currently the thermostat is in the hall keeping the back of the house cool. The heat from the ...
2
votes
1answer
37 views

Why does my furnace have a yellow termainal?

I don't have the manual for my furnace, and the terminals are labeled C W R G and Y. The internet generally refers to Y as Cooling or Compressor. So what does Y do on my furnace?
1
vote
2answers
5k 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 ...
2
votes
1answer
61 views

Old Rheem rhqa 1000 to thermostat wiring help

I cannot figure out how to wire my 30+ year old AC to my lux dmh110a thermostat, I do not have the old thermostat to reference. It seems to be 4 wires coming out of the air handler and to the ...
1
vote
1answer
59 views

Can someone please explain this gas water heater thermostat marking

What I don't understand is the box with a slash through it located counter clockwise from the larger solid bar. I'm sure it is less warm than the large box, but does it have a special meaning? I ...
1
vote
1answer
121 views

installing ecobee SmartThermostat with Voice Control on older home

I recently purchased the most recent ecobee Smart Thermostat with Voice Control. The existing thermostat needs to be updated. However, I'm not sure if I'm able to install this without installing the ...
2
votes
0answers
39 views

Connect “C” wire on boiler model number 1135-601

I've read several threads here and on the other websites but still can't figure out how to add C wire to my boiler wiring. I would like to replace my old mercury thermostat with Nest E or any other ...
0
votes
0answers
309 views

Condo fan coil thermostat fan never turns off, cooling is humid

My thermostat in my condo is a honeywell thermostat and it the only options it has are System and Fan. Fan is set to auto (other option is Lo Med Hi) and the System is set to Cool (or Auto or Off). ...

1 2
3
4 5
18