Tagged Questions

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
47 views

Is the Nest thermostat smart enough to turn itself on BEFORE you get home?

I'm wondering if in "Away" mode, is Nest smart enough to learn about when you come home, and kick on approximately 30-40 minutes BEFORE then? Or does it only kick on when it senses you've come home? ...
0
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0answers
48 views

Honeywell WiFi Smart Thermostat Wiring

The Honeywell WiFi Smart thermostat was operating fine when on AC until the heat went on this fall. Now, each time the fan goes on, the thermostat loses the connection, turns blank, then reboots ...
0
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1answer
39 views

Where do I connect the C wire in my furnace?

I am upgrading my thermostat to a Nest, and would like to add a common wire. My current furnace controller doesn't have a C terminal, but the current thermostat wire has 2 unused wires (black and ...
0
votes
1answer
63 views

My attic unit already has a wire connected to C, can I still connect a wifi thermostat? [duplicate]

I have an extra wire I can use for the C wire on both ends but in my attic the main unit has a wire already attached to the C spot and going away from the unit to something else. Can I attach two ...
0
votes
1answer
134 views

Where to add C wire on this air handler?

Thanks for helping me here. I am adding a new wifi thermostat to my system but need to add a C wire directly to the air handler (system is a First Co air handler with hot water boiler for heat and ...
0
votes
2answers
166 views

Where is my common wire on the unit?

I have 2 systems in my house, my heat is gas hot water radiator heating and A/C is a separate newer system. I'm trying to figure out if I can run a C wire off air handler from the A/C system to run ...
0
votes
1answer
53 views

Why did I have to change the wiring to use a smart WiFi thermostat?

I just installed a Emerson Sensi wifi thermostat.It works, and I ran a separate C wire. I had a 24 volt 5 wire Robertshaw programable thermostat that ran my boiler, air handler and AC. It is all ...
1
vote
1answer
121 views

Can I connect an additional wire to HVAC system where all the terminals are full?

I'm installing a new thermostat (ecobee Smart Si) and it requires "C" wire. I checked before I bought, and saw an unused blue wire behind my current thermostat. However after connecting everything the ...
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0answers
14 views

Updating thermostats to single system

I have a three floors in my house, each controlled by it's own thermostat (separate air handlers and mechanical valves on furnace). Baseboard heat. The three thermostats are controlled separately, ...
-1
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1answer
50 views

Deactivate thermostat [closed]

I have a roommate that constantly turns the thermostat down to 65 during the winter months. Is there a way I can deactivate it, while maintaining a comfortable 72?
2
votes
0answers
118 views

How do I install a WiFi thermostat with a Well-McLain steam boiler?

I have a Weil-Mclain 150000 BTU steam boiler, and have only 2 wires connected to my thermostat, but would like to add a new Honeywell WiFi thermostat. I have no C wire, no A/C, or any other type of ...
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0answers
24 views

How can I install a Honeywell Linevolt Pro 8000 in a multiple thermostat situation?

My roommate who just moved out installed a Honeywell Linevolt Pro 8000 in his room several months ago (replacing an M602 with no brand name that I can find) and it seems to have worked fine - it had a ...
0
votes
1answer
202 views

How can I install a Honeywell RTH65800WF Wifi thermostat?

I am having some difficulty figuring out the correct wiring for my new wifi thermostat. Before I bring out the A/C technician, I was wondering if anyone here might be able to help? Searched other ...
2
votes
1answer
110 views

How do I connect a C wire to an Utica PEG112CDE steam boiler?

I want to upgrade my old mercury thermostat that I currently have to a newer programmable thermostat. This little DIY project is for my first late 1920's home that I recently purchased. I currently ...
0
votes
2answers
294 views

Where to attach the “C” wire to my furnace?

I am upgrading to a new thermostat which requires a "c" wire to power it. I have an unused blue wire running from my thermostat to my furnace that I plan to use as the common wire. However, I am ...
0
votes
1answer
77 views

How can I replace an old dial thermostat on an oil furnace with Hydrostat 3250 Plus?

I recently bought a home with an oil fired Biasi furnace that has a Hydrostat 3250-Plus attached. It uses an old analog round dial thermostat, and I'd like to replace it with a new digital (wifi) ...
0
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2answers
38 views

Is it possible to create a better temperature controlling system?

I have a two story 2.5k sq ft house with a varying degree of temperature throughout the house. The main problem is that the air coming out of vents are very weak if almost nil. Only the living room ...
0
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0answers
320 views

Where to connect a c-wire on a furnace with existing two wire mercury thermostat

My existing thermostat is an old mercury two wire device, heat only. Looking to upgrade to a better model, but I need to run a c-wire. I don't know where to connect the wire at at the furnace, any ...
3
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2answers
64 views

Can a furnace with a variable speed blower be used in a multistory house?

I just had an HVAC guy out to give me an estimate on a new Carrier Infinity series furnace and he said the second floor rooms will always be colder because the thermostat is on the first floor and not ...
1
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0answers
31 views

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 ...
0
votes
1answer
34 views

Should my A/C compressor come on when I turn only the fan on?

I have a bog standard HVAC system with a Nest thermostat. When I tell the theromostat to turn the fan on for 15 minutes the A/C compressor also kicks on. Is this normal?
0
votes
1answer
25 views

choosing a programmable thermostat: wiring and power

I want to replace my non-programmable RobertShaw 9500 thermostat with a programmable thermostat. The current wiring uses these terminals: RH, W, Y, G. With that set of wires, can I get a ...
0
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0answers
13 views

Why does adding 2nd Wifi thermostat not work in 3 zone home?

Our home has 3 zones for forced air heating by oil and central AC. I replaced a Robert Shaw thermostat with a Honeywell Wifi unit and it worked fine. I then replaced another Robert Shaw thermostat ...
0
votes
1answer
25 views

thermostats for high desert climate

We live in Spokane, WA, a high-desert climate. We don't need a programmable thermostat, but we do need one to keep an constant ambient temperature range. This may mean A/C during the day, and heat at ...
2
votes
1answer
38 views

How do I determine/control which heat source is used (heat pump, oil)

I have a heat pump and an oil furnace for backup. How does the HVAC system know when to use the heat pump and when to use the oil furnace? Specifics: I have a Honeywell TH8320U1008 thermostat ...
0
votes
1answer
408 views

Which terminal should be used for a “C” wire when none are labeled “C”? Older electric furnace/heat pump

I have an all electric air handler/furnace connected to a separate AC unit and it is also a heat pump. I've purchased the latest and greatest Honeywell WiFi "Smart" Thermostat and it needs a C wire. ...
2
votes
1answer
367 views

Where do I connect my C wire from my thermostat when there are two transformers?

I have a Laars gas boiler that has 3 heating zones. I want to replace the old mercury honeywell tstat on the 1st floor (heat only) with a newer honeywell RTH9580 wifi model. I've taken pictures of my ...
0
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0answers
154 views

Furnace not working properly with digital thermostat

I have been attempting to use several different types of digital thermostats to replace my old mercury thermostat, however none of them are able to control the furnace properly. All of them are able ...
1
vote
2answers
76 views

thermostat batteries replaced, AC unit won't start

Came home from work to find no AC. I checked the thermostat and the display was blank. After replacing the batteries and resetting the program, my AC unit never started up. I checked: - The AC unit ...
0
votes
1answer
69 views

How to connect a DIY thermostat to the HVAC System

I am building a DIY thermostat similar to this blog. I want to connect it to the HVAC system of my home. How do I do that? I found this post which is very informative but doesn't completely answer my ...
0
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0answers
21 views

Need to run a “C” wire to thermostat but control board has no “C” [duplicate]

I am looking to replace a thermostat with one that needs a C wire... which my current thermostat does not. I have some extra wires in the thermostat wiring that are unused... so I went down to the ...
1
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3answers
93 views

A/c makes the lights turn on and off! No Joke!

The lights on the first floor, upstairs bathroom and upstairs Laundry room won't work. The breakers did NOT pop The air conditioning was running this morning but is not working now. When the ...
1
vote
1answer
339 views

Where can I connect the C wire on the A/C side?

I’m trying to replace my thermostat with the Honeywell Smart-WiFi thermostat. Quick summary, I have an extra yellow wire which I’m making the C wire, but its not connected at the other end and I’m not ...
0
votes
0answers
65 views

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 ...
0
votes
2answers
594 views

Can I install a Honeywell WIFI Thermostat?

I have done quite a bit of research and have not been able to find an answer I am looking for. I currently have a manual digital thermostat that is not programmable made by Braeburn. My system is a ...
0
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0answers
39 views

Connect Taco Radiator system to a new Honeywell wireless thermostat

I have a Taco model 572 valve connected to an existing wired Honeywell TH8110 thermostat for my oil fueled radiator system. I'm getting a new Honeywell TH6320 wireless thermostat for a new A/C ...
1
vote
1answer
91 views

Zoned oil furnace and AC thermostat question

I recently moved into a new home and wanted to replace the old thermostats with digital Honeywell ones. From what I understand the home has a Rheem 10 Seer (1996) compressor and a Williams oil furnace ...
0
votes
1answer
61 views

air conditioning system stays on even when we turn off our thermostat

Our A/C system stays on even when we turn off our thermostat. What should we do to try to fix it?
2
votes
1answer
66 views

Is it a problem that I have two of each color wires on my Honeywell thermostat?

I am thinking about upgrading my Honeywell thermostat. Every thing I have seen describes / shows a single wire for each color. My current thermostat has two wires connected to each terminal (two green ...
0
votes
1answer
116 views

Is my thermostat transformer voltage too low?

I measured the voltage at the thermostat Rc to G and Rc to Y terminals, and they read 16.2V and 16.34V respectively. Shouldn't I be measuring 24V+/-? I purchased a Nest thermostat and it will not ...
0
votes
1answer
75 views

Which wire is the C wire?

Model: Goodman AWB30-08C Electric AC/Heat I'm hoping someone can help me identify the 24V C wire. Fortunately the thermostat line has a spare wire already run, so I just need to find the C wire in ...
1
vote
2answers
102 views

Honeywell home ventilation system with no c wire for thermostat. How can I substitute the g for the c without blowing a fuse?

I'm hoping to get some help with my thermostat problem. We bought our home brand new and it came with a very basic thermostat (non programmable and runs on batteries). I want to upgrade it to a wifi ...
0
votes
0answers
168 views

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 ...
2
votes
1answer
128 views

Can I insulate between a brick chimney and drywall?

Can I insulate the space between a brick chimney and the drywall inside my home? I am getting heat transfer from the brick to the drywall in the summer from the sun heating the brick. My thermostat ...
1
vote
1answer
152 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 ...
0
votes
4answers
5k views

HoneyWell Wifi Thermostat and C wire

I just bought the HoneyWell Wifi thermostat and so wanna use it. However my old Thermostat was battery powered and does not use the "C" wire. I opened up my panel and found that there were three ...
1
vote
1answer
94 views

Can I change my standard thermostat to a Wifi one?

I have a (quite standard) TR-010X T6360A thermostat that looks like this: And this is the wiring diagram: Can I install the Heatmiser PRT-TS WiFi Touchscreen Programmable Thermostat? This is the ...
0
votes
1answer
980 views

Is it possible to use add-a-wire with my current configuration to add a C-Wire? [duplicate]

I only have four wires: Red, Blue, Yellow, and Green. My old thermostat jumps the R to RC and leaves C empty. I have a new thermostat that wants 5 wires, but I don't have C. I am not sure what the ...
1
vote
0answers
97 views

Using a second thermostat to balance temperatures thru fan-only control

Like many others, temperatures between the two levels of my house are uneven. This is particularly noticeable as spring arrives and the upper floor (above ground) enjoys solar heating (so the heater ...
1
vote
3answers
8k views

Adding a C wire to a new Honeywell WIfi Thermostat

I am trying to install a new Honeywell touchscreen WIFI thermostat and need to add a C wire to my terminal inside the furnace (using the help found at How can I add a "C" wire to my ...