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

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0
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0answers
10 views

Need to find control valve for damper

There is no control valve attached to this damper: so I can't turn it to open/close the duct. It's currently closed :-(. It's smooth so I haven't found anything that can even grasp onto it tightly ...
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0answers
26 views

AC is freezing after one day of full use

I had my AC unit serviced two months ago. The unit is about three years old. This week is the first week we have had it turned on all day. Last Sunday I noticed that the AC was on, but no air was ...
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1answer
28 views

Should storm windows be removed if AC will be on and windows rarely opened?

We generally run our AC most of the day. I am wondering if it is a detriment to leave the storm windows on (b/c they create a pocket of hot air) or a potential benefit (by reducing the escape of cold ...
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0answers
41 views

AC Unit does not receive 24 volts on outside unit

My outside unit does not turn on itself, but it does work. I just did a quick repair just thinking it was the capacitor and it was only 15 dollars for a new one so I changed that out and still had the ...
0
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1answer
15 views

HVAC compressor turns on when calling for fan only

I just moved into a new apartment with HVAC, and I'm looking to control the thermostat with a few Phidgets (I had already invested in that ecosystem, so I just needed a couple of relays). Anyway, ...
3
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0answers
12 views

I would like to view answers and answer questions [migrated]

I would like to view answers (and answer) questions. I have years of experience in construction and HVAC, but little experience with computers. How can I get a few reputation points to do above?
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0answers
35 views

Removing stuck “through the wall” air conditioners

I have two through wall air conditioner units that cannot be removed. These were installed within sleeves in the 1970s and have been sitting there ever since. One budges a little and the other, not at ...
0
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1answer
11 views

Fan runs when in “on” mode, but not when in “auto” mode while in “cool” setting

I have a Rheem RHPL-HM2421JC air handler, a Rheem 1.5 ton heat pump condensing unit, and a comfort control thermostat. The heat and fan worked well over winter. I can also turn the fan mode to "on" ...
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0answers
28 views

Yellow wire connected to C terminal, blue wire connected to Y terminal at furnace

I'm trying to install a new smart thermostat the requires a C wire. My old thermostat operated on batteries. The pre-existing wiring system of the old thermostat looked normal (ie. red wire to Rc, ...
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1answer
26 views

How do I wire my old 3/4hp 115-120v 50-60Hz HVAC motor to make an exhaust fan?

My old HVAC blower motor has the following wires and I would like to know how to wire them to a typical 110v plug for use as a garage exhaust fan. yellow (N) black (L) yellow/green (ground) black (M1) ...
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0answers
13 views

Why does my hvac minisplit freeze up?

What would cause a mini split to freeze up? The Freon level is correct and the air flow is good. This is a multi head system (2) one is working properly the other is freezing up.
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0answers
12 views

Can I increase the “constant on” speed of my air handler?

I have an American Standard TWE049E13CB air handler with a variable speed blower. The manual has a chart to adjust the dip switches for fan speeds for cooling, heating, fan off delay, and auxilary ...
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0answers
16 views

Outside 4 ton AC unit bad [closed]

I purchased an outside AC unit, 4 ton, from a person on Craigslist a couple of months ago. I was given a written one year warranty by the seller. When I had it installed yesterday we found that the ...
1
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3answers
85 views

Five Year Mystery - Unable to find source of burning smell from HVAC system

There is a burning smell that wafts out of the vents of my 15-year old, 3-level townhouse (top level is a full unfinished attic with no HVAC). The bottom level of the townhouse is the main level ...
0
votes
1answer
27 views

Run HVAC fan throughout the day for comfort

At my old house, we replaced the HVAC with a high efficiency unit that came with a thermostat that would blow, say, 50% to 70% of the time for air movement to increase comfort level. I'm not sure but ...
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0answers
49 views

How do I connect a honeywell wifi thermostat with no C wire at the furnace?

I purchased a Trane XV90 furnace in 2001 & I'm upgrading the thermostat to a Wi-Fi model. This thermostat needs a wire labeled C from the furnace & of the 4 wires coming from the furnace none ...
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0answers
19 views

A/C Insulation on Evaporator Unit [closed]

The issue is however the Lining of the A/C Unit inside was found to be Glued to the Sides and bottom which I believe is called the "Pan". The Apartment had an issue of Mold as the A/C was 3 ton unit ...
-1
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1answer
38 views

What is the difference between the coolness of different wall types in hot weather

Given a 30cmx30cm concrete beam and pier structure, with infill, and year-round (equatorial) daily temperatures of around 25C-33C, with around 80% humidity. What is the difference between these ...
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1answer
58 views

Central Air Unit not Sending Enough Power to Thermostat

Right now I don't have specifics on my central air unit (make, model, etc) but hopefully the info I provide will help. I have a Second Generation (and Third Generation) Nest Thermostat hooked up to ...
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0answers
24 views

Improving air flow using supply and return exhaust fan with split type air condition

I have slight issue with uneven temperatures between two rooms. Say we have two rooms, Room 1 (cold room with AC) and Room 2( without AC, hotter room). Room 2 is ventilated by Room 1 AC by opening ...
3
votes
2answers
29 views

Window unit lets in lots of outdoor noise. How to insulate?

I just moved to NYC and I have a window unit like this: The foldable frame around either side lets in a considerable amount of outside noise; it's just as if the window was open. In fact, I'd swear ...
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0answers
6 views

furnace blower not working off of thermastat

I replaced mother board of furnace and the fan blower turns on but my wires from thermastat are not plugged in.black wire on Hi red on low white on com if unplug hi it does not turn on
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0answers
12 views

Safe to install a 3 Ton HVAC with 8" ducting

I currently have a pretty old 2.5 ton HVAC installed and it broke down recently so I need to replace it. I've had a couple companies come out and give me bids and they both insist that I need to ...
0
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1answer
38 views

AC Condenser Fan Won't Spin and Overheats But Can Be Kickstarted

Symptoms: AC kicks on, but blows warm air Found issues: AC kicks on and AC condenser appears to turn on (makes noise), but the fan won't spin. A few seconds later, the condenser fan motor overheats ...
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0answers
17 views

Clean filters and dusty house

I have good airflow and a very dusty house and large dust balls. I have used all kinds of filters including the pleated. When filters are checked in 3-6 months they are as clean as the day they were ...
1
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0answers
40 views

AC capacitor testing with multimeter

When running through my check list to start the AC for the spring/summer I noticed the outdoor fan was not running, hence no cooling. I'm using a basic digital multimeter to test a capacitor with the ...
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vote
0answers
42 views

Thermostat will not power on with C wire, but it has voltage

I recently purchased a Honeywell wifi thermostat and tried to hook it up as a replacement for an existing battery powered unit. I have a typical forced air HVAC setup with gas furnace (no heat pump), ...
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0answers
14 views

Comfortmaker Run Capacitor Location?

Where is the blower run capacitor likely to be physically located within a Comfortmaker central HVAC unit? Access is tight in the attic space. Thanks!
0
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0answers
33 views

Theremostat indicates low battery even with new cells

I have a 3 story home with 3 different thermostats, one on each level. The first floor one says "lo batt", so I changed the batteries. That thermostat still reads "lo batt" and my system will not turn ...
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votes
3answers
26 views

Mount horizontal 6" metal exhaust pipe to wall economically?

I'm trying to add more ventilation to the back room of my garage. The only available outside air exit location is 25' horizontally along the front room of the garage's wall. I have 6" 30ga sheet ...
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0answers
24 views

5 year old Air handler fan not rotating or slow

5 year old Heil AC unit not cooling. It appears the air handler in the attic has a fan that is not turning when I turn on cooling from the stat. If I turn on the fan from the stat it turns but ...
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0answers
11 views

Replacing Flex Duct

I have few questions and need some advices. 1. can you tell me the size of my unit. It is Bryant, model 561CJX018000AEAA 2. The furnace is in crawl space and connects with 12" flex duct, 40 feet long, ...
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2answers
48 views

How do RH/RC/R and Y/W relate for HVAC?

I have the following notes for HVAC (that I've compiled from reading through here): Thermostat wiring: C low voltage power wire that brings power from heating/cooling equipment to thermostat ...
0
votes
1answer
45 views

Does it take long time to turn AC unit around?

I am wondering if it can take a full day of work to turn around AC unit like in this post . Must my new air conditioning unit be 3 feet from the wall (or positioned backward)?
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2answers
29 views

can I use AC top cover for Trane XR16

My contractor installed this system yesterday, at my property: "Trane T4TTR6060C1000A RX16 5 TON XR16 A/C 16 SEER rating R410A". ...
1
vote
1answer
86 views

Must my new air conditioning unit be 3 feet from the wall (or positioned backward)?

My contractor installed this system yesterday, at my property: "Trane T4TTR6060C1000A RX16 5 TON XR16 A/C 16 SEER rating R410A". Everything is working fine. I just do not like aesthetically how he ...
1
vote
1answer
34 views

What could be causing my Thermostat “R” wire to only be 8 VAC?

I am trying to install a Nest thermostat. It says Rh not powered. I checked with a meter and I get approx 8 VAC reading. What could be causing this? The furnace itself ain't pretty. Update: ...
1
vote
3answers
60 views

How is the Air Conditioning wiring supposed to connect to my furnace?

My dog has chewed through my wires on my unit that turn on my fan at the ac unit. This is not the first time. Its always been an easy fix until now. He actuall pulled the wire from the unit and I ...
0
votes
2answers
52 views

reclaiming exhaust from 'on demand water heater'

Is there some way to recover the heat which is lost through the exhaust system from a 'on demand water heater' ?
1
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1answer
28 views

What is 3" (750Pa) wg class?

According to Sheet Metal & Air Conditioning Contractors’ National Association (SMACNA) - leakage test manual, It is not recommended that duct system constructed to 3" (750Pa) wg class or lower be ...
0
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0answers
8 views

Need to clean permanent air filter

How do I access the permanent filter in a RUUD product ? The model number is either UBEA-14JO5SFFAI or RCGA-24A2GG14?
2
votes
1answer
28 views

Why doesn't AC equipment come with dehumidifier only option?

Every AC unit dehumidifies when cooling is on. I'm just wondering why dehumidification only is not an option, as is in standalone dehumidifiers? E.g. my basement stays pretty cool even in the summer ...
1
vote
3answers
53 views

Compressor/fan stays off when cooling turned on

Before I begin, I would like to request "call a technician" suggestions to stay off. I do know a nice guy who can look it up for me, for a variety or reasons, one of which being my general history of ...
3
votes
1answer
90 views

Mounting a window air conditioner on top of a sliding horizontal window

I need to install a window air conditioner in my master bedroom. However, the only suitable window there is a horizontal sliding window. To complicate things more, I need to place it on top, since my ...
4
votes
3answers
184 views

Why would Central AC, Fridge & Pool Pump All Fail Within 3 Days?

Could this be systemic? Something in the electrical system for instance? Or is it likely coincidental? HVAC repair says they can't find a leak but the freon is very low and was fully charged in ...
2
votes
0answers
27 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 ...
3
votes
3answers
81 views

Duct Cleaning: Is Duct Sealer Necessary, Non-Toxic?

A professional contractor is cleaning AC Ducts, and after he scrubs the ducts, he wants to apply an acrylic duct sealer and de-odorizer. The container of the duct sealer has minimal lableing and does ...
0
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0answers
93 views

Swapping out Nest for Ecobee - c-wire issues

We are trying to replace our nest with an Ecobee (with remote sensor capability). We have an existing Nest thermostat which was installed on our boiler/radiator system last year. Back then, we had ...
2
votes
3answers
106 views

Will a 2-stage heat pump cool my upstairs on low stage?

I am currently upgrading my furnace from an oil furnace/AC combination to all heat pump. I am considering two stage vs single stage heat pumps. I understand that two-stage will supposedly give me ...
2
votes
2answers
20 views

Zoned heating system very warm even without heat on upstairs?

I know heat rises, but our 1st story floorplan house gets pretty darn warm during the winter months. Other than turning on the AC or opening windows in the upper story zone, anything else that could ...