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

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2answers
47 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... ...
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1answer
58 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 ...
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0answers
48 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" ...
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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 ...
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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 ...
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2answers
37 views

What would make my ac unit hiss

I live in a mobile home and my central ac unit starting hissing pretty loud 3 days ago and tday it is blowing only warm air. There is no water or ice inside or out. The outside unit is running but it ...
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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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1answer
99 views

Less than 24 volts on the thermostat C wire

We have a brand new air handler at work, but the thermostat is mounted on a wall next to a server/computer room which is always warmer than the rest of the office. I want to install a thermostat that ...
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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 ...
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1answer
32 views

How long should a heat pump last before needing repairs?

We have a Goodman heatpump Model: SSZ140601 Model Desc.: 14 SEER HP, 5 TON Mfg Date: 6/3/2010 First of all, we did not register the unit so that cut our warranty in half. Two weeks ago, our ...
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2answers
44 views

A/C unit cycles on and off

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 ...
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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 ...
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1answer
320 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 ...
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1answer
128 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 ...
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0answers
32 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 ...
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3answers
143 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?
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3answers
47 views

Cooling radiators in summer?

How efficient would it be to use radiators circulating with cold water, to cool house in summer? Wondering if anyone has tried this, and how well it works? I was thinking about H/AC in general, and ...
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1answer
21 views

My home air conditioner that's inside the house, seems to be sputtering when coming on. What could this be?

My home air conditioner inside the house; when it's going thru its normal cycle of off and on, it seems to be sputtering and/or hesitating to come on. It's like or similar to a car that having a hard ...
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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 ...
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0answers
28 views

Cleaning of TempStar air conditioning parts

It's been 6 years since I bought the Tempstar 4 ton a/c. So far, it is running okay. But when the need arises, I want to be BOLO and do the repairs myself. So, how do I clean a TempStar a/c ...
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1answer
55 views

How long should it take to a 1.5 tons AC to cool down a 2000sqf house from 80F to 77F?

I know that it might depend on a lot of things like: -how air tight is the house -how old it is (insulation, windows etc) -what windows are installed -BTW I have casement window -outdoor temp (...
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1answer
25 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 ...
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0answers
34 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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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 ...
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0answers
41 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
50 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
127 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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1answer
27 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, ...
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0answers
97 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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1answer
46 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
192 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
52 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
26 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
31 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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3answers
99 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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2answers
72 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
238 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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1answer
131 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
38 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
56 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
7 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
17 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 ...
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1answer
81 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
19 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 ...
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0answers
76 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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0answers
112 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
23 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!
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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 ...
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3answers
30 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
27 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 ...