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

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1answer
60 views

My master bedroom is hot! Should I install a return in my master bedroom?

Thanks for taking the time to read my question. I have a house where the master bedroom was added in during an expansion. The master sits half above unfinished basement and half above crawlspace and ...
0
votes
1answer
286 views

Central AC is Icing up, but not cooling my house

My central air conditioner isn't cooling like it used to. I noticed that the refrigerant lines entering the evaporator coil in the plenum were icing up. What might the problem be?
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5answers
59k views

How much cooling can I expect from a central air conditioner?

Yesterday's high was 106.0F, low of 79.2F, full sun all day. AC set at 78F, indoor temperature reached about 85F. Today's high was 105.4F, low of 81.1F, full sun all day, now about 102 at 7pm. AC ...
1
vote
1answer
44 views

help with improving HVAC performance on the second floor of an old house

I'm hoping some of you can offer some advice on how best to add a second AC in our home -- or on whether we should look for a different solution. I should say upfront that I've done a lot of reading ...
1
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0answers
58 views

High Power Bills Related to Air Conditioner

So I seem to be having trouble with my power bills (they've often been near $400 while other people in my area with a similar sized house usually get around $140), and I've isolated the issue to my ...
1
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1answer
46 views

Replace insulation in a Trane HVAC? (TWE030C140B0)

I found a little mold on the foil covering the insulation in my TWE030C140B0 air handler/ AC/Heater. I am 95% sure I have the moisture problem resolved and now I need to replace the insulation. Does ...
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1answer
88 views

HVAC - Circuit Board Fuse blows on AC Switch

I have a Honeywell System. Back in November of 2014, I replaced the Circuit Board with one by Honeywell from Amazon (1014460). The blower motor was replaced over 2 years ago. Last month, I have ...
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1answer
40 views

My AC unit won't blow cold

So, I was changing a light switch and flipping circuit breakers to find the correct one. I accidentally flipped my AC circuit breaker off and then back on. After this I noticed the AC wasn't blowing ...
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2answers
35 views

Does the air temperature outside at the time of spring inspection matter when the tech comes to inspect and clean the inside and outside units?

I have semi annual inspections done on my A/C units both inside and outside. Will the temperature outside effect the tech's ability to properly clean and evaluate the operation of the units? The ...
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0answers
26 views

Should drip pan be replaced with install of new furnace?

We just purchased our first home; part of the agreement of purchase was that the previous owners had to install a new furnace which was done by a professional installer from a reputable company in the ...
4
votes
1answer
88 views

Is it necessary to discharge the capacitors on an AC condensor?

I intend to replace the capacitors on my house air conditioner condenser. This video claims that discharging the capacitors is not necessary, because the circuitry will discharge through the fan ...
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6answers
8k views

How do outdoor mist-cooling A\C units fare in real-world usage?

I live in Phoenix where summer outdoor temperatures regularly exceed 110°F and humidity around 15% or lower is not uncommon. In this environment a mist system can easily pull the temperature down ...
0
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1answer
77 views

Water dripping out of small pvc pipe in soffit of house

Yesterday was an extremely hot day here in SoCal with temperatures around 100F. The AC unit had been turned off during the daytime and at nighttime we turned it on to cool down the house. A few ...
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0answers
245 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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3answers
10k views

Is it possible to use my window A/C unit without actually installing it in the wall?

So, here's the dilemma. I want to install a window unit in my garage. I know how to do this, but my wife isn't supportive of the idea because we are trying to sell the house currently. Anyways, ...
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3answers
491 views

How to recharge a window unit air conditioner?

Can I recharge my window unit air conditioner or do I have to send it to a specialist? The AC unit that I have is about 15 years old (nothing lasts forever)... and I happen to have about 20 lbs of ...
1
vote
1answer
28 views

Air handler blower, motor, or something else?

My blower just stopped working. I have 240 volts to the motor but it won't spin. It will turn an inch or so but that's it and it tries repeatedly. Could it be something besides the blower or the motor?...
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1answer
25 views

HVAC thermostat current

What is the typical current (in mA) carried by the 24v thermostat HVAC wire bundle in a typical low voltage application? I'm using 18/7 wire.
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0answers
41 views

Carrier Central Air Conditioner Model 38CKC042-340 with 35/5 instead of 40/5

I have this unit Carrier Central Air Conditioner Model 38CKC042-340 I was looking at http://www.repairclinic.com/Shop-For-Parts/a41b370d1182307/Model-38CKC042340-Carrier-Central-Air-Conditioner-...
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2answers
89 views

How to move from RH/RC thermostat to C thermostat in AC only system?

I see this is a pretty common question, but the answer seems like it might be dependent on your thermostat and air handler, so I'm posting with my specific questions. I'm upgrading from a White ...
0
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1answer
29 views

Moving from R22 to R410a

Outside Unit Carrier Central Air Conditioner Model 38CKC042-340 Inside Unit Carrier Furnace M/N : 58STA090-10116 I am very newb, i have no idea if there are other parts involved besides the ...
0
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1answer
109 views

How long does it take to add 1 lb. of refrigerant to an air conditioning unit?

My HVAC unit was running but not cooling properly. I called an HVAC guy who came to check. He came without a scale and told me he can fill the refrigerant and tell me how much he filled by just ...
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0answers
40 views

Window air conditioner fan slows to a stop in about 2 minutes

I just bought a window A/C unit and turned it to "low fan" setting. Within I think a few seconds after it started, I could hear it slowing down, which it continued to do until it came to stop, which ...
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1answer
44 views

Repairing Leak in Refrigerant Lines

We recently found and pinpointed a leak in my copper refrigerant line (the non-insulated line) and was wondering if there was anyway to repair and replace that one spot on the line (like if there were ...
0
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1answer
18 views

Trane Air Handler GAT2A0C48S41SAA Create “C” Wire

Can someone please Tell me the Best way to Create a "C" Wire for a WiFi thermostat Honeywell Wi-Fi Smart Thermostat (RTH9580WF). I currently have a Trane thermostat TCONT602AF22MA. Please... Thanks ...
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0answers
18 views

Forced air heater filter. Pros and Cons of reusable/washable filter?

When the gas service person came by to turn on the gas after termite tenting they saw that our air intake filter for the forced air system was dirty. He offered some advice and said that there are ...
1
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2answers
56 views

Feasibility of replacing cracked AC condenser fan blades

A few minutes ago the fan blade in my AC condenser split down the middle. I'm assuming it's been cracked/split for a while now and it finally just gave up. It looks simple enough to replace... ...
2
votes
2answers
12k views

Does a compressor with a short to ground really require a complete system replacement?

My 24 year old home A\C went out some time Sunday morning. I had a tech come out and look at it, and was told that the compressor is shorted to ground, and that this means I have to replace the entire ...
6
votes
4answers
28k views

How can I improve second floor HVAC performance?

I have a forced air heating and air conditioning system that performs poorly on the second floor: It is way too warm in the summer and a little too cold in the winter. I live in a 1920s masonry row ...
1
vote
1answer
60 views

HVAC making sound even when off

At Thermostat Fan was on Auto Cooling was On Outside Unit was making noise. Outside Unit Fan not coming on at all Next to the compressor on the Wall there was On Off Switch, I turned off power ...
5
votes
7answers
37k views

How much less power does a three-phase air conditioning unit use than a one phase unit?

I'm planning to install a 5 ton central AC. I'm deciding between a condensing unit that runs on 220V and a costlier unit that runs on 207Y three-phase. My understanding is that three-phase motors use ...
0
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0answers
51 views

Smart Thermostat C-Wire wrong voltage

I'm looking to upgrade the thermostats in my apartment to ones which I can control programmatically over WiFi. I opened up one of the old thermostats and discovered I have the classic "C-wire" ...
0
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1answer
172 views

How can I adjust a whole-house ventilation bathroom exhaust timer?

We have a home built in 2008 in west-central Minnesota. As a cost-saving (I perceive it as such, and may be mistaken) measure to fulfill air quality and venting code, the builder set up an upstairs ...
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0answers
14 views

Furnace added to second Floor

I am ripping my entire house apart and will be making almost an entire wall out of windows and doors,(glass). I will be changing all of the floor plans, (walls), so at the moment I am adding HVAC to ...
3
votes
2answers
174 views

Can't get my AC to turn on at all

Recently our AC stopped working. The thermostat is working properly, but the unit just started blowing hot air. I've never worked on a AC before, but I was trying to save some money. Anyway: I ...
0
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0answers
11 views

ac unit and thermostat

I replaced the fan motor and the capicators and the thermostat but the fan still don't shut off and continues to run after the thermostat has stopped and the fan gets very hot and l have to shut it ...
0
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2answers
208 views

Issues after capacitor replaced on AC unit

Had a checkup on my AC/ furnace a couple weeks ago. The technician said the capacitor leaking oil and not pulling enough amps. He recommended me getting a whole new system. (My house was built 6 yrs ...
4
votes
1answer
57 views

What inspections/maintenance should be done before first air conditioning of summer?

I'm a typically handy guy who knows his limits. I recently moved into a new house so am unfamiliar with the history of the equipment. Before I switch the thermostat to A/C for the first time this ...
0
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0answers
16 views

Reducing AC vent/diffuser

I want to add some smart vents to my home control system. The thing is, the largest size that they come is 12x6, and my current ceiling vent/diffuser is 12x12. I would prefer not to have to go into ...
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0answers
26 views

Random Outages on only 5 of my breakers. Open/ Bad Neutral?

Every morning when dawn comes around (5:30 - 6:30 am) the power on 5 breakers in my house seem to kick on and off with power. The breakers are my water heater (electrical/ no gas), my a/c, my kitchen ...
2
votes
1answer
143 views

What components need to be changed when upgrading from R22 to R410a?

What equipment will change when I convert from R-22 to R-410A? I don't want to get rid of my current heater as it's a hydro-thermal unit that uses free heated/recycled hot water. Can I get away with ...
1
vote
1answer
42 views

Limit switch doesn't function on oil furnace

my limit switch on my oil furnace does not shut off the burner when it hits the limit.I replaced the limit twice maybe I had a bad one still no luck . While furnace was running I took the thermostat ...
4
votes
6answers
6k views

Do I need to level the outdoor AC cooling unit?

I've read somewhere that the outdoor AC unit needs to be leveled. My outdoor unit is a bit slanted due to the floor not being completely flat (pic below). However, I don't see any obvious structural ...
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vote
3answers
71 views

Duct sizing impact on flow

We have a ranch with a wood fireplace in the living room. It's fantastic at heating the main living area, but the bedrooms down the hall get left in the cold. I'm going to install insulated flexible ...
0
votes
3answers
186 views

One portable air conditioner - want to use it in two rooms

I have a Kenmore portable air conditioner model - 408.72012. this particular model can be housed on the outside of the building and the A/C air is vented into the inside space (normally through a ...
0
votes
1answer
29 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 ...
0
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1answer
37 views

Does a central A/C with copper lines that are too small cause compressor and diaphragm failure?

I have a 3 ton R410A A/C unit that is 8 years old and is using copper lines that are too small. Does this cause leaks, diaphragm failure, and compressor failure? The air was not blowing cold, so I ...
1
vote
1answer
324 views

Anyway to hack a portable AC unit to cool 2 rooms [duplicate]

I am looking to take a portable AC unit and hopefully run a tube through a wall in another room while still cooling the room the unit is located. I have searched to attachments that could help but ...
0
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0answers
33 views

Should I have a ceiling fan whose blades extend to the register?

Currently, the ceiling fan fixture and the 10x6 register are spaced by about 32" (~2 stud lengths). The room is about 350 sqft. Should we purchase a 70" ceiling fan so the blades extend out past the ...
0
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3answers
159 views

In what circumstances would an AC produce no condensate but still cool the air?

In what circumstances would an AC produce no condensate but still cool the air?