Questions tagged [hvac]

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

406 questions with no upvoted or accepted answers
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2k views

Difference Between Take Off and Starting Collar - Which One Should I Use?

I am in the process of installing a whole house humidifier. I am planning to mount it to the supply side and need to connect the bypass to the return. I'm not sure if I should be using a take-off or ...
3
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1answer
35 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 ...
3
votes
1answer
371 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 ...
3
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0answers
55 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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2answers
109 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 ...
3
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1answer
371 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 ...
3
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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
votes
2answers
270 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 ...
2
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0answers
20 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
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0answers
31 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 ...
2
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0answers
26 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
51 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-...
2
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1answer
36 views

How to handle air condenser with garage addition

I'm planning a garage addition onto my house and want to know what the best way to handle existing A/C condenser units that are there is. The current setup is as follows (with the C's being the ...
2
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0answers
34 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 (...
2
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0answers
18 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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2answers
210 views

wiring furnace blower to turn on when make up air damper is powered to open

I have a make up air damper that is opened to supply make up air to the system return air duct when the kitchen range hood is operating. There is a pressure sensor in the range hood vent duct that ...
2
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0answers
31 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 ...
2
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0answers
36 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
20 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
votes
1answer
154 views

Another “How do I add ”c" wire to boiler for Nest

I have tried searching this forum and others, but I could not find anyone with a situation like mine. I thought it better to ask here, rather than damage something. I have a Lennox wall mounted ...
2
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0answers
129 views

Junction Box Blank Cover in HVAC Duct

I am starting a bathroom remodel second story that requires a length of NM wire to be lengthened by a few feet. I realize I can't do this hidden in a wall or floor and need this done in accessible ...
2
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2answers
3k 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
votes
1answer
93 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(...
2
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0answers
72 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
votes
2answers
279 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
votes
1answer
657 views

Can I install a heat-recovery ventilator (HRV) in a garage?

I am building a high efficiency home in N. Minnesota, 2x6 construction, slab heat, spray foam insulation etc. Need to install an heat-recovery ventilator (HRV) unit, but only have space for it in the ...
2
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0answers
559 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
votes
1answer
154 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
votes
2answers
139 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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0answers
7k 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
73 views

Air handler for an AC in the attic collect about 1 cm of water in it before it is high enough to drain… problem?

My air handler in my attic won't drain water(because the hole is 1cm above the pan) until the water reaches that hole. Why is this setup this way. From what I have read, NO water should be in the ...
2
votes
1answer
583 views

New Thermostat installed but compressor comes on immediately

I have a new Insteon Thermostat that I'm using to replace my prior Honeywell t-stat. This is installed to a relatively new HVAC system (both AC and Heat) that DOES have a "c" wire. I've attached the ...
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
612 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 ...
1
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1answer
45 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 ...
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0answers
23 views

Ecobee3 Wiring With Heat Pump

I have an eEcobee3 I've been trying to get working with my HVAC. The HVAC is a heat pump, with the air handler in the attic. The current thermostat is a RiteTemp 6025. It's currently wired up at ...
1
vote
1answer
25 views

Installing new heat pump, should I have the return line replaced or not?

I have a 2000 sqft. house and need to replace a 4-ton R-22 system that uses a 1-1/8" return and has a short line run with the condenser 8 feet lower than the evaporator. I have received quotes ...
1
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0answers
19 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". ...
1
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0answers
45 views

Cooling a Room with No Windows

I am trying to determine the most effective way to cool my bedroom which runs about 5 degrees warmer than the rest of the living space: Questions: What is the most effective way to bring the bedroom ...
1
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0answers
59 views

Need help connecting “C” wire, unknown red and white wire from one unit to the other

We are replacing our old thermostats (installed in 2006) with two smart thermostats. We have 2 separate units and thermostats. We have an unused blue wire (c wire) at both thermostats. We thought we ...
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0answers
24 views

HVAC Wiring Help

A little backstory should help... my parents built the house in 1996 with no central air. They added central air in 1999 and it was fine till three years ago. We had a programmable thermostat ...
1
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0answers
28 views

How do I design an ice house?

Where can I find how to design a cold room storage building? I have a 12x12 shed that I use as cold storage for tree seedlings for about a month each spring. The present construction is 2x4 walls ...
1
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1answer
18 views

Replacing swamp cooler pads

I have a AercoCool Pro 4800 swamp cooler roof unit and need to get new rigid pads for it. Do the pads need be specific to the brand according to the cooler's spec sheet, or can I use any pad that is ...
1
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0answers
23 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
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0answers
17 views

DIY Solarium / Four Seasons Room - Project Planning Advice

I am located in Columbus, Ohio. I currently rent, but I am planning on buying a house in the next two years, and I want to get started on planning for this project. My wife is a houseplant enthusiast, ...
1
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0answers
18 views

How to connect different HVAC components each with a blower

If there are multiple HVAC components, each has its own blower; for example: Furnace/heater with blower : for heating Air handler with blower : for cooling and dehumidifying, and (optional and if the ...
1
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0answers
48 views

Can I install an electrical outlet on furnace closet wall?

I'm remodeling my unfinished basement. I'm building a closet to enclose the gas furnace and water heater. Can I install an electrical outlet on one of the walls? This would be facing outward ...
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0answers
15 views

Drafts coming from all floor Heating system ducts. Gaps between sheetmetal and floor have been sealed

I had my heating system, crawl space furnace and leaky poorly insulated sheet metal duct work, replaced a couple years ago with a 96% efficient system. The system was independently tested and ...
1
vote
1answer
66 views

wiring hrv in a confusing house

some beautiful pictures first time posting apologies if my placement is off Buying HRV. I am debating between two units, venmar evo5-700 which doesn’t support furnace interlock or lifebreath rnc205, ...

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