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

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0
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1answer
24 views

Are HVAC Transformers Interchangable (if their power ratings match)

I'm troubleshooting the blower not starting in a friend's HVAC system. We think the issue is either a) a blown transformer, or b) the relay that controls the blower has blown. The next step is to ...
0
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0answers
27 views

Both A/C air handler and outside unit won't turn on

I went to turn on my A/C for the first time this year, and nothing happened. I checked power to both the air handler and outside unit...both at getting 220v going into the boards on each. I then ...
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0answers
95 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 ...
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0answers
37 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 ...
1
vote
1answer
41 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 ...
1
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3answers
97 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 (...
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0answers
61 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 ...
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0answers
122 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, ...
0
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1answer
46 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
17 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
23 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 ...
0
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1answer
93 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 ...
13
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5answers
11k views

Ethernet cable instead of Thermostat wire?

I need to pull new wire from my furnace to my thermostat and was wondering if there would be any problems in using an Ethernet cable instead of standard thermostat wiring. The reason being is I have ...
3
votes
3answers
3k views

How can I heat up my apartment to kill bedbugs in Southeast Asia?

I have a bedbug problem in my apartment and I want to fix it myself with heat. (I do not want chemicals sprayed around.) Apparently, getting a room to 140 degrees for two hours is sufficient to kill ...
0
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0answers
33 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
1answer
133 views

Should I install the jumper on my new limit control?

I needed to replace fan and limit control (White-Rodgers, model 5D51-35), because the fan switch was broken (fan would constantly run) and heat would not stay on. I took a picture of the control, ...
3
votes
2answers
39 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
15 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
votes
1answer
60 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 (...
1
vote
2answers
324 views

Gap between 6“ dia wall thimble & 6” hvac pipe

I bought a 6" dia aluminum wall thimble to vent my 6" dia hvac steel exhaust pipe through to the outside. However, the diameter of the 6" thimble is actually 6 3/4". How do I effectively insulate the ...
5
votes
4answers
22k views

Can I using a 3-phase connection to power 1-phase AC unit?

I have preparation for an AC connection with 3-phase 220V 3X16A breaker. I want to install a 220V 1-phase unit, which also needs a 16A breaker. The physical connection has screw-on terminals, so there ...
1
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0answers
18 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
56 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 ...
1
vote
1answer
76 views

How to power Honeywell wifi thermostat with external transformer

I want to install A Honeywell RTH 6580 WF thermostat in my garage for heat only . My heater is a simple LP gas, hanging unit heater; heat only and my thermostat has two wires labeled W and R . I ...
0
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0answers
34 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 ...
1
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0answers
95 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), ...
1
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0answers
21 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!
2
votes
2answers
13k views

How should I evaluate my central A/C to see if it's working properly?

I was once told by a service tech that they evaluate how well the system is performing based on temperature difference between the the return and supply sides. On our first really warm day (80F+), I ...
1
vote
1answer
4k views

How do I connect my whole house humidifier to my furnace?

Connecting Desert spring Humidifier to the furnace: Do I eliminate the 24V transformer that came with it? The furnace Keeprite has the the electronic board says Humidifier W1 and C. where can I ...
0
votes
3answers
27 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 ...
3
votes
6answers
48k views

What could be causing an A/C blower motor to turn off randomly?

The Blower motor on my AC unit turns off at random times while the outside unit continues to run which is causing the coil to freeze up. The blower won't come on for 30-45 minutes after the AC has ...
4
votes
4answers
16k views

How can I connect two indoor ductless A/C's to one compressor?

I have one Hitachi i-clean split AC 2ton unit installed in my home. I want to connect another indoor ductless unit to the already installed outdoor compressor. I only need to use one indoor unit at a ...
0
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0answers
26 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 ...
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:
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votes
0answers
12 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, ...
0
votes
2answers
58 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
50 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)?
1
vote
1answer
91 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 ...
0
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2answers
46 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". https://drive.google.com/folderview?id=0B7uO-n40pIiESGJBdmhlUnFkbDQ&...
1
vote
3answers
78 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 ...
3
votes
1answer
194 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 ...
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
vote
1answer
33 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
10 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?
1
vote
3answers
98 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 ...
2
votes
1answer
36 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 ...
3
votes
2answers
130 views

What could cause my Carrier furnace fan to sometimes stop running?

I have a Carrier system: FURNACE 58UVB080; AC 24APA530, CONTROLLER SYSTXCCUIDO1-B, approximately 7 years old. New filter, impeccable condition. I was initially told by the licensed installers that ...
11
votes
5answers
17k views

How can I calculate how large an airconditioner my house needs?

I know there are a lot of possible factors that go into determining the size of the air-conditioning system a house needs. Is there a standard way of calculating what is needed, or do A/C companies ...