Questions tagged [hvac]

(Heating, Ventilating, and Air Conditioning) For questions about installing, repairing, and troubleshooting HVAC systems.

456 questions with no upvoted or accepted answers
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45 views

Replacing my Honeywell thermostat with a Nest heatlink in the UK

Can someone help with this. Trying to pick the C wire and the NO wire from here. Please note I am in the UK [![enter image description here][1]][1] [1]: https://i.stack.imgur.com/EPkJh.jpg![enter ...
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1answer
40 views

4yr old heat pump doesn't label 24v C wire

I'm used to the gas furnaces, and I still want to swap out this 4 year old heat pump, but it would be too expensive. I recently bought a smart thermostat to try and help with the utility bills, but it ...
3
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0answers
98 views

How is an air handler's fan controlled if its control board doesn't have a G terminal?

Background I have a 2-stage cooling heat pump unit from Bryant, installed ~2006 (central Florida): Condenser model 698BNX048-B Handler model FE4ANB006 Shortly after moving in ~5 years ago, our evap ...
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1answer
156 views

Could clogged exhaust cause codes 13/33 on my furnace, and how do I check and clear?

My Carrier Performance 96 series furnace (similar to the 59TP6 currently shown on Carrier's website, but I don't have the exact model number in front of me) has been showing codes 13 ("Limit Circuit ...
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1answer
1k 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
59 views

Why isn't my furnace igniting?

I noticed cold air from my Carrier 58SS furnace. The main burners were not lighting. The pilot flame was strong, but yellow. When I tapped on the gas valve, the pilot shut off. I removed the pilot ...
3
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1answer
562 views

Can a motorized damper be installed inside existing ductwork?

My HVAC system consists of a fan, furnace, compressor-driven AC, and evaporative cooler. The problem is that there is a large air volume used only by the evaporative cooler that is generating a lot of ...
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0answers
2k views

Trane Weathertron Stat to Honeywell RTH2510

I have a Trane Weathertron thermostat thst I am replacing with a New Honeywell RTH2510. This is a heat pump with auxiliary electric heat. The wires on the Tran thermostat are. R, T, O, G, Y, B, X2 ...
3
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2answers
298 views

A/C unit cycles on and off during cooling phase

My outside compressor / condenser is cycling on and off, even though the thermostat is calling for A/C. The blower in the house still runs, and the thermostat is working properly. (I opened up the ...
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0answers
33 views

Home Heater Ignition Failure

My house’s heater uses a hot surface ignitor. The ignitor won’t come on. All I hear is the motor running and no attempt at ignition. A professional checked it out and said electronics are good. This ...
2
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3answers
43 views

Heat/AC Unit Cover

I'm living in co-op building in northeastern part of Queens, New York and have heat/AC unit in the apartment. Two questions: Do you know what's the technical term for such unit? It's not just ...
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25 views

Should I expect a whole-home humidifier to provide consistent humidity throughout a 3-story townhouse?

I'm looking to install a whole-home humidifier in my 3-story townhouse in northern Virginia. I already have trouble keeping a consistent temperature throughout the 3 stories - should I expect similar ...
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32 views

Replacement HVAC blower motor fails within 24 hours?

My unit is a Carrier Infinity (FE4ANF003T00ABAA) with an ECM 3.0 blower motor. To start, the thermostat reported a “Code 41 - Blower Motor Fault”. I ordered a refurbished motor + control module online ...
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0answers
103 views

Will a backdraft damper in a air return duct cause issues with the gas furnace?

In our attic is a gas furnace for the 2nd floor. The attic is not insulated (except for the attic floor which is the 2nd floor ceiling). The air return for this furnance is in the 2nd floor ceiling on ...
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117 views

How does this wiring work?

I have a Trane XV90 and XL 14i. The wiring looks a little strange as in the picture bellow. _____________ | | BK W2 W1 R G Y B/C YLO O |___||...
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0answers
20 views

Inconsistent damper control and ventilation control settings

While changing my dual-zone HVAC system's filters I noticed a lack of consistency in damper control and ventilation control settings. There are two of each type of control. The first damper control ...
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0answers
24 views

trying to add honeywell wifi thermostat to old furnace

I see there are lots of post asking about the "C" wire and wifi thermostats so I apologize in advance for another one. I'm trying to install a new Honeywell T5 thermostat for my not so ...
2
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0answers
54 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 ...
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0answers
32 views

Why would a wall-mounted AC unit with a digital thermostat seem to be reading outside temperature when the fan isn't running?

My apartment has a wall-mounted AC unit with a digital temperature setting, which works great, but it has a consistent problem where its thermostat appears to read much differently than the actual ...
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0answers
60 views

Rheem RGDG unit turns on w/thermostat off, blower come on and inducer motor switches off and on

I've having a problem with my rheem model rgdg-10nbrjr The air conditioning works, turning it on at night it blows cold air and the house indeed gets cold. However the furnace unit itself ...
2
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0answers
274 views

Trane HVAC condenser fan runs backwards

I installed a new fan motor on my Trane condenser. It's 240V three-wire Genteq motor that's described as clockwise shaft-up rotation https://www.northamericahvac.com/trane-american-standard-...
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0answers
84 views

How to wire Aprilaire 600a to older furnace

I need help wiring an Aprilaire 600a humidifier yo my older oil furnace (from 1998). I thought I had followed the wiring instructions properly, but the digital humidistat is giving me an error code (...
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0answers
40 views

Water not circulating through baseboards

2 zone (1 radiant floor, 1 baseboards) hot water heating system. Radiant floor (t’d off main feed) seems to be working fine. None of the baseboard loops are hot, and the pipe was hot before the ...
2
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0answers
45 views

New thermostat turns fan off when set to on, never turns off on auto

My oil heat furnace was functioning normally on an old mercury switch thermostat, but I wanted to replace it with a programmable Honeywell 5+2 one. There were Y, W, G, R, and B wires screwed in on the ...
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0answers
37 views

New Unit with Blocked Condensate Lines

A little over 30 days ago a new HVAC unit was installed at my home. Saturday night I had a buckled ceiling and a BIG problem. The installer told me both primary and secondary lines were clogged—-the ...
2
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0answers
25 views

Trane HVAC in horizontal position - why does evaporator throw condensation?

I appreciate assistance from anyone who has had or understands the problem. I have a Trane HVAC system in a horizontal "left" flow configuration in the attic. Ambient temperature is about 95 ...
2
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2answers
9k views

Dripping sound emanating from interior wall space

I've seen some other questions about dripping sounds but wasn't sure if my situation fills the same circumstances or not. I have a 2-story home and only a partial understanding of where the ...
2
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2answers
145 views

Thermostat White-Rodgers 1F82-261 switches to stage 2 heat for no apparent reason

I am running a central heat system that uses a heat pump as stage 1 and a gas furnace as stage 2. The thermostat used is the White-Rodgers 1F82-261 which supports 2 stages of heat. When using regular ...
2
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1answer
127 views

Mini-split HVAC in new build?

Next few weeks I will be in the process of getting quotes for mini-split HVAC system. Curious, if anyone has gone ductless and if so, how is that working out? The house will be a a two story build(...
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0answers
95 views

Replacing a motherboard on a Carrier 8000VS Furnace

Hi guys, I am trying to finalize the wiring of my new carrier motherboard. I have about four more wires to connect and the new motherboard is slightly different than the old one. The pictures I’ve ...
2
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2answers
336 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 ...
2
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0answers
715 views

Installing Ecobee3 with Trane Furance

I am installing an Ecobee3 and have found that, while the common wire exists, it is not connect to the furnace. The wiring schematic for my specific furnace can be found in this PDF There is no ...
2
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1answer
171 views

HVAC turning off below 30 degrees

A bit of a long post but I've tried to be as specific as possible I had a new Goodman HVAC put in Dec 2016 (model GPG1430060M41AB). For the last nine weeks the system has been cutting out when the ...
2
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2answers
145 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 ...
2
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1answer
10k views

Goodman gas furnace limit switch opening, blower only runs with a/c

I apologize in advance for some of my incorrect terminology. My father has a 2004 Goodman GMH80904BN gas furnace with a/c. The a/c has functioned properly all summer here in Ohio, we have recently had ...
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0answers
9k views

Increasing gas pipe size from 1/2“ to 3/4” at appliance

I'm planning to purchase and install a new condensing tankless water heater (Takagi T-H3J-DV-N) that will supply both domestic hot water and space heating (radiant via heat exchanger, separate closed ...
2
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0answers
3k views

Reducing air conditioner compressor vibration noise

I have a two year old Carrier air conditioner with an outdoor condenser. The condenser sits on a plastic pad on the side of my house, and I have two--one for downstairs and one for upstairs. ...
2
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0answers
681 views

How can I insulate and elevate an A/C line set on a flat rubber roof?

The Scenario An apartment building with a flat black rubber roof. The A/C condenser is on a platform on the roof with an air handler inside the unit. The line set runs across the roof for about 20 ...
2
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0answers
860 views

What are good Relative Humidity and Temperature settings on an MHRV and are the settings related?

I need to configure the threshold Relative Humidity and Temperature settings on an whole house MHRV system. The way the system works is that if the RH threshold is exceeded the system increases the ...
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1answer
38 views

can you combine a regular return filter if you have a electrostatic hvac filter system

can you combine a regular return filter if you have a electrostatic hvac filter system as the house? we moved into a house that has this system but my kids have allergies and i understand that the ...
1
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1answer
59 views

Nest thermostat and old HVAC

Last year the Nest (used only for cooling) was working after connecting the blue C wire to the HVAC. Last year I made it work only after I put the green wire for the fan in ob. Now, when the green ...
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0answers
38 views

AC Replacement Proposal

Can someone please help to review if the following AC replacement proposal makes sense and sounds reasonable? Installation Remove and disposal of existing equipment, disassemble systems so they can be ...
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2answers
52 views

issue with closed loop hot water heating

So I have an 1880s Victorian in Boston that is proving to be quite the adventure. I'm new to this, so hopefully I am using the right words. I have a four zone hot water heating system with radiators ...
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0answers
41 views

Brand new Fujitsu Halcyon split system unable to keep temperature

We had a Fujitsu split system installed, with 4 indoor units. The issue I'm seeing is that the system is behaving in a way that I can only describe as "erratic". We're observing a couple of ...
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0answers
49 views

Opportunity to relocated HVAC system from attic to basement

Our >10-year old HVAC system (heat pump and 3-ton air handler) need to be replaced. The heat pump is need of new parts, but we were advised given the age of the entire system that it would be more ...
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0answers
56 views

C Wire - Williamson Furnace/Honeywell Thermostat

I'm trying to install a new wifi thermostat, but am a little confused. I have 5 wires, but none are connected to the C in the thermostat, as seen below: Additionally, when I trace the thermostat to ...
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0answers
18 views

Diagnosing CH 05 (communications failure) in LG mini-split system?

I installed a mini-split system in my shop (it's the second mini-split I've put in; the first went great). Everything appears fine, except that after a few minutes, the system shuts down and the ...
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0answers
36 views

Furnace setup switches seem to be in the wrong position

My furnace (Bryant 926TA) has to arrays of setup switches. I am particularly concerned with SW1-3 (off in my picture) and SW1-4 (on in my picture). The manual calls SW1-3 Low Heat Rise Adjustment and ...
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0answers
31 views

How to balance pressure in a multi-zone damper hvac with an always on bypass valve

Background I'm the new owner of a multi-family home where the previous owner was a large corporation that made money by overspending on renovations. Thus, they tended to renovate with top-tier ...
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0answers
46 views

Carrier Weathermaker 9200 Humidifier Ecobee blows 3amp fuse

I have a Carrier weathermaker 9200 with a bypass humidifier attached. I just moved into this house a year ago and the humidifier never worked with the humidistat. I tested the solenoid by putting a ...

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