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

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0
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1answer
80 views

central A/C Turns back on 30 seconds after shutting off

First of all, the a/c system is probably 30 yrs old. The outside unit stays running when the inside unit shuts off. After about 30 seconds, the inside unit turns back on again, and will sometimes only ...
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0answers
58 views

Smaller Footprint of new Furnace Base Cabinet

Replaced downdraft furnace in 1950's ranch house built on slab. Base cabinet of new furnace has a smaller footprint than the original resulting in a 4in. gap between the edge of the cabinet and the ...
0
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1answer
33 views

How can I plug a hole cut in a window pane for a portable A/C unit?

I just moved into a room where there is a portable A/C unit. To create a vent for the unit, a hole was cut in the glass of one of the window panes that spans about 13.5 cm. I was told that the unit ...
1
vote
1answer
38 views

HVAC tripping breaker - things to check before replacing?

HVAC system (we're in Houston, it's still hot here) stopped working Tuesday. A/C guy came out, determined it was tripping breaker. Would trip immediately after resetting, but after a couple of ...
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0answers
31 views

Can my A/C unit knock out my whole trailer or is it coming from the main box outside causing the problem?

I'm confused. Do you know if my air conditioner unit would blow out the main power in my whole trailer if the box inside my house isn't tripping? It keeps making a very loud popping noise under my ...
2
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2answers
2k views

AC unit won't turn on: both inside blower fan and outside fan unit won't turn on

AC unit won't turn on: both inside blower fan and outside fan unit won't turn on. It is as if I had gone to the circuit breaker and cut the power to the whole HVAC system, but I didn't. I've been ...
1
vote
2answers
115 views

Window AC not cooling

I've GE window AC 0.75 ton it has stopped cooling I cleaned the nylon net properly with old tooth brush,it was totally blocked Then I combed the metallic horizontal fin like structures which were ...
4
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3answers
519 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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5answers
4k 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 ...
1
vote
1answer
66 views

What is causing this air-conditioning unit to cool on cold days?

This is a temperature log from a reverse cycle air conditioning system that has run fine for getting on for 30 years. It has suddenly started to blast out cold air on days when it should be heating. ...
8
votes
5answers
1k views

What type of regular maintenance should I be doing on my central air conditioning unit?

I have not done any maintenance on my central air conditioning system since I bought my house five years ago. Everything seems to be running fine but is there some sort of maintenance I should be ...
4
votes
4answers
224 views

Is transitioning to all electric heating smart?

I am in the process of overhauling my home heating and plumbing. I bought a 2600sq/ft 1980s Cape Cod in southern Maine on the coast. I've reinsulated the walls and roof and am continuing to make ...
3
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4answers
4k views

How “freely” should a central A/C condenser fan spin

Last year my home's central air condenser fan motor stopped working. When I noticed the house wasn't cooling down I went outside to investigate and found there was a humming sound coming from the ...
2
votes
1answer
53 views

How to manually control HVAC without thermostat?

I would like to create a solution (Probably with Arduino) to control my AC remotelly. Opening my thermostat and doing some tests I got these values bellow: Blue (C) - Neutral (AC) Red (R) - Phase ...
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2answers
58 views

HVAC breaker issue

My HVAC (Tempstar 5300XL) comes on automatically at the preset temperature. It may run cold for 45 minutes to an hour, then trips the breaker. What is the most logical problem, and solution?
0
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1answer
34 views

Are there testers for thermostats?

One of my A/C units was struggling to keep the temp. down to 85 three weeks ago. The pipe outside was slightly frosted so I already knew the unit was a little low of refrigerant. Called repair company ...
0
votes
1answer
68 views

Upstairs/downstairs cooling- leave it on or off?

It's 100+ here in Texas. My house has separate air conditioners for upstairs and downstairs. We rarely go upstairs, but I'm told that we have to account for air flow "chimney effect" up the stairway ...
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2answers
4k views

Air handler condensation draining problem

For the life of me, I cannot figure this out. My air handler and heat pump were installed in 2006 and work great. For the first summer since I've owned the home, condensation started to not drain ...
0
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1answer
282 views

Help installing new thermostat

disclaimer, this is my first attempt at doing any type of electrical work, so apologies in advance for any wrong terminology :) I attempted to install a new Honeywell programmable thermostat. When I ...
0
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1answer
103 views

How can I prevent a secondary condensation drain line from dripping down the side of my house?

I have 2 central AC units in my 2 story house. From what I was told by the last AC repair man that visited, each of my ac units in the crawl space/attic has a main drain line that drains directly ...
1
vote
1answer
67 views

Can dehumidification be achieved in a typical US residential forced-air system without dedicated components?

We have a very typical forced-air HVAC system with a medium-efficiency gas furnace and split-system central air conditioner in our house; however, latent load buildup (i.e. stickiness) is a problem ...
0
votes
3answers
85 views

Problem- air condition- compressor and fan outside not on

I'm new to hvac. My ac was working fine but it decided to die one day. I've been able to fix my ac, but it continues to happen(the same problem), and it is not easy to get to the ac (it's on the ...
0
votes
1answer
86 views

Furnace is Sweating an Abnormal Amount

I noticed my furnace sweating a couple days ago. It's hot and humid where I live so I was only mildly concerned. It was a high of 74F today with humidity around 70% which is, relatively, nothing. ...
2
votes
4answers
12k views

How can I calculate the power consumption of an A/C unit?

I have an AC unit with the following specs: Cooling Capacity: 1260 kcal/h, 1.47kW, 5000 Btu/h Fan Motor Power: 0.034 kW Current: 0.155 A My question is how much power does this unit actually ...
2
votes
3answers
331 views

HVAC system that pulls-in cold air from outside?

My house has an existing forced-air heating system and I'm looking at getting central AC added in a few weeks' time (indeed, I've booked contractors for estimates next week). An AC system would keep ...
0
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0answers
37 views

Ac running but my blower will not

My ac unit stopped feed cold air from the unit outside. The main fan on top is spinning fine and my lines are freezing but the blower in the unit is just barely turning. Can someone tell me what would ...
8
votes
2answers
10k views

What could be causing an orange flame on all appliances?

I have an orange flame in all my gas appliances (gas furnace, gas water heater, and gas stove) and cannot seem to determine the cause. Background So far, I have had the gas company come out. I had ...
0
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0answers
55 views

Older home with no AC plenum…replace our entire AC system as suggested?

We have an older home that has a large living-area/fireplace room; the AC unit sits over it in the attic. Earlier this year, in that room, we noticed a crack beginning to form in the ceiling sheet ...
0
votes
1answer
49 views

HVAC leaking cold air at unit: seal with tape?

I was in my crawlspace today and noticed that there was cold air leaking from a grouping of three round openings in my unit (pictured in the middle of the photo below). The outer two holes had rubber ...
1
vote
1answer
148 views

How can I determine the start up amps on a 3 phase 5 ton A/C unit?

I am trying to properly size a home generator and my concern is the start up amps on a 5 ton AC unit (15 years old R22 Goodwin type). My home power is unique because we have 3 phase (the AC is on 3 ...
1
vote
1answer
84 views

Why would my house be so humid even when the A/C is running?

I live in Florida which this year has been particularly hot and humid. However, a while back I noticed mold in my closet and a very musty smell in my living room. Actually I even found mold growing on ...
0
votes
1answer
64 views

Should I add a return or another supply to a large room with only one supply?

I just moved into a new house and I have that one room that always seems to be hot. It's on the 2nd floor of the house with the attic over it. The other 2 rooms on the 2nd floor are always a nice ...
1
vote
1answer
84 views

Why would the condensing unit fan shut off but not the compressor?

We have an allegiance 12 unit circa 2001, model 7a2024a100a3, the fan starts up and runs for about 5 minutes then shuts off, the compressor is still on and seems to build up a bit the "flush" or so it ...
1
vote
1answer
38 views

Can using a new evap coil on top of an older furnace cause problems?

I am getting quotes for a new R410A condenser unit/evaporator coil from several HVAC contractors. A salesperson refused to give me a quote unless I purchase a new furnace as well. He said that he has ...
0
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0answers
29 views

Goodman A/C unit sparks at high pressure line on furnace. Blows breaker

Got a 10 year old A/C unit and notice breaker blown. Flipped breaker and noticed a spark where the high side line goes into the plenum of the furnace and the breaker blew again. A/C repairman checked ...
0
votes
1answer
120 views

Water Heater Gas B-Vent Install

I installed a new water heater and want to vent it right. The old water heater used ABS pipe since it had a blower. Basically I have a 3" b gas vent pipe coming in and connecting to a flex gas pip ...
0
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0answers
48 views

What could cause a 5 ton Goodman packaged unit on the roof to turn on and off randomly?

With the thermostat on cool and manual the unit (fan + compressor) will turn on sometimes right away, and sometimes after hours. Then it'll run for either minutes or hours before turning off, either ...
0
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0answers
53 views

Furnace not working

I came home to my furnace having no power even to show trouble codes. I turned off my breaker opened the blower door and it had a blown 5 amp fuse on the curcuit board. I replaced the fuse turned the ...
0
votes
2answers
72 views

2 PVC Pipes running from unit to basement

I have two 2" PVC pipes running from outside (AC unit) to the inside set up (furnace?). I need to cut these pipes and re run them since they are blocking the water heater which I need to take out. I ...
4
votes
3answers
6k views

Why is my gas furnace vibrating when blowing hot air but not when blowing cold air?

I have a gas furnace. I recently replaced a bad blower motor. At that time I also cleaned out the blower housing and squirrel cage. The AC runs fine with no vibrations or any symptoms of an off ...
1
vote
2answers
198 views

lennox AC condenser Fan running backwards

I have been trying to figure this out for a little while and about to check into the nutty house!! The Condenser fan went bad in my AC Unit. It was a 3 wire motor. I got a Universal replacment motor ...
0
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0answers
38 views

Why does my furnace blower motor stop working after 20 minutes?

The furnace blower motor stops working after 20 minutes, but the central air unit outside continues to run. The blower motor will not start again until after it has cooled off or unless I assist the ...
5
votes
1answer
4k views

Where should carbon monoxide detector be located?

How many carbon monoxide detector is need in house and where it's more strategic to place it? Is it better to place it low close to the ground or high close to the ceiling?
5
votes
2answers
3k views

What is the maximum angle I can set my window AC unit?

We know an AC unit must be angled to allow runoff. But what is the maximum angle and what is the issue with having to large of an angle? I've seen people say the angle is "5/16" or "3/16" but this is ...
0
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0answers
42 views

AC fan not turning on. It's silent

Replaced the capacitor 2 weeks ago because AC (Lennox) outside fan was not running, blowing in warm air. And the unit started working. Then again yesterday (95F outside) same thing. Replaced the ...
2
votes
2answers
511 views

Is there a way to turn on the air conditioning only on certain days?

We're looking for a way to turn on the air conditioning at our camp, say on a Thursday night, so that it will be cool when we arrive on Friday evening, but to shut it off if we don't go to the camp ...
0
votes
1answer
82 views

Closet where AC/Heater fan is located is very cold

I noticed that the closet where my heating unit/AC fan lives is super cold. I measured the temp using a black and decker IR thermal leak detector and the temp in the closet is about the same temp as ...
0
votes
1answer
874 views

Blower fan works w/ heat “auto”, not with a/c “auto” or on “on”

I've read the posts with the opposite issue, which have been helpful (you guys are amazing!) but still no solution. Problem is that the blower fan does not come on when system is on "Cool" and fan is ...
7
votes
8answers
13k views

Where should my furnace filter go in a Lennox G40UHX series furnace?

I have a Lennox G40UH(X) series furnace, which is installed in our attic (We have a single-story house on a slab). Because the furnace is installed in the attic, it is "laying down" on its side, and ...
1
vote
2answers
189 views

Foil tape failure in HVAC unit

On a recent trip up into my attic, I found out that the air conditioner was blowing cold air into the attic. In several places at the AC unit, the foil tape had become unsealed. In the interest of not ...