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

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1answer
14 views

Can I move an attic furnace downstairs

I love the single unit HVACs. I hate the unit in the attic - it has leaked so many times. Now that I am ready to replace the attic unit, I was wondering if I could have the same setup as my 1st floor ...
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0answers
18 views

HVAC 3A fuse shorting on cool

I recently came back from a trip, and the thermostat was still working. On turning the AC on, the wall-powered thermostat decided to die. Upon investigating in the attic, I noticed the 3A fuse had ...
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1answer
26 views

A/C Air Handler Leaking Water Everywhere

I have a relatively old air handler that has worked fine for many years. Just recently, it started leaking water everywhere, and it seems to be seeping from inside the base of the air handler itself ...
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2answers
49 views

Can I pump down an Air Conditioner myself?

We are planning on having a new concrete patio poured in a couple of weeks and need to move our AC unit to make way for the slab. Is it possible for a layman to pump down the coolant and move the ...
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0answers
11 views

Can I add another heat run to my furnace?

I'm looking to add a bedroom to the basement and would like to add a heat run to the new room (return air will occur through an opening between the ceiling joists). This seems easy enough, but I ...
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0answers
15 views

How to fill / seal in-slab hvac ductwork?

My house is built on a slab. Within the slab are "channels" which act as ducts for the HVAC system. I assume it is partially lined with metal but based on photos from an HVAC-cleaner, it's hard to ...
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0answers
7 views

How to fix uneven central heating and air?

My central heating and air conditioning system does not heat my home evenly. Half of the house gets significantly warmer / cooler than the other half. I have tried adjusting the registers, but to no ...
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0answers
12 views

Will a Carrier heat pump generate hot air in the heat mode if the compressor is bad?

The heat pump works ok in putting out heat, but puts out hot air in ac mode as well. Had an hvac tech look at it. He replaced the capacitor and said the compressor was bad. Can the heat pump put ...
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0answers
20 views

Adding dual zone capability to an existing HVAC system in a house with existing 2 zone manual ducting

I have a house that has existing dual zone ductwork in place (separate ductwork for the upstairs and downstairs) that has manual dampers. I recently replaced the HVAC system with a new geothermal unit ...
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1answer
40 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 started ...
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0answers
19 views

Where does the C wire connect in a dual transformer system?

When wiring a common ground (C wire) for a dual transformer system, does it matter which transformer you connect the ground too? I'd assume that the ground on either transformer would serve as a ...
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0answers
16 views

Troubleshooting pressure error code for Trane XV80

I have a ~7 year old Trane XV80. Recently, it started throwing up the pressure error code (3 flashes). Inducer fan would start, but the burners wouldn't light. Being lazy, I would basically power ...
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1answer
79 views

Can I connect two wires to a single screw terminal in my HVAC system?

I am installing a new honeywell WiFi thermostat but the old battery operated thermostat had batteries and no "C" wire. I look at both the thermostat and the air handler and found an extra un-used blue ...
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0answers
5 views

No “C” terminal on Trane air handler [duplicate]

I am installing a new honeywell WiFi thermostat but the old battery operated thermostat had batteries and no "C" wire. I look at both the thermostat and the air handler and found an extra un-used blue ...
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0answers
25 views

Can I remove HVAC pipes after exposing the ceiling?

I recently removed the drywall ceiling from my basement and have two related questions about removing the HVAC ducts/pipes. Pictures attached here: http://imgur.com/a/qep4w 1. Is it OK to remove the ...
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3answers
30 views

Why does the outside fan stop but the blower fan continues to run?

We can have the thermostat set on 76 but wont stay 76 in house. Will come on when temperature is 79 in the house.
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0answers
33 views

Central AC Tripping Circuit Breaker (sometimes)

When my AC first turns on, it will typically trip the circuit breaker shortly after the compressor and fan start up. If I reset the breaker, and turn the AC back on, it will usually run just fine and ...
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0answers
45 views

heat pump/air conditioning wiring to thermostat

We decided to change the thermostat of our heat pump/air conditionnning unit. First 3 images are the old unit. The first 3 wires(1 and 2 picture) yellow red orange were not connected to anything, just ...
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1answer
41 views

Allergies and an economizer

I had an economizer added to my HVAC system last fall, which is fantastic for cooling my second floor down in the evenings during the shoulder seasons where the weather is cool in the late afternoon ...
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0answers
19 views

How to Change Chinese HVAC Thermostat

I am looking to put Nest thermostats in the house, I have now found out my entire house (one in each room, 6 of them) has been wired with HVAC Chinese U12A UNIVERSAL A/C CONTROL SYSTEM urrgh – they ...
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2answers
114 views

Should I convert from a rooftop to a split HVAC system?

We have a packaged HVAC on the roof and the AC needs to be replaced. It's 23 years old and dying/dead. We were considering buying just an AC and keeping the package unit running for heat. We feel ...
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2answers
35 views

Is having a branch off the end of main heating HVAC duct bad and if so, why?

Question: Is having a branch off the end of main heating HVAC duct bad and if so, why? Background: A heating and cooling contractor sales representative came to my home today. He saw the situation ...
3
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1answer
76 views

Should I be worried if my A/C ran with the cover on?

My wife accidentally switched on the "cool " mode and the a/c was activated, however the cover was still on the unit outside. Ran like this for about 2 hours. I noticed it and turned it off and went ...
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3answers
65 views

How to hide AC lines up against brick siding

I had this AC system installed, and didn't realize when asked about what location i'd prefer the compressor that it would look so ugly having it off the corner of the building instead of in the middle ...
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1answer
33 views

Smart Thermostat - No C-Wire - No Controller Board

This one seems to be a little different from previous questions on the subject. Here is the dilemma, I don't see a transformer. I have included a few pics. There are Three wire bundles. For ease ...
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1answer
25 views

How can I add a C wire with this unusual installation?

I recently got a new Honeywell WiFi thermostat, which requires a C-wire. I have 5-wires going to my current thermostat, with only 4 being used. So I thought adding the 5th as my C-wire was going to ...
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2answers
71 views

HVAC contactor sparks when AC kicks?

The HVAC and control board is a McQuay Mark IV. I'm not sure if I would like to try and fix this myself yet. Just trying to figure out the issue before deciding where to go. Here's the scenario: ...
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1answer
40 views

What should I do after a low-voltage wire was cut putting the furnace door back on?

I have the basic Honeywell thermostat that a lot of people have. All the thermostat wires go to the blower in the attic (for the central air). They are spliced with wires that then go to the furnace. ...
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0answers
40 views

Why would my AC turn on and off randomly?

My AC unit turns on and off randomly regardless of whether the thermostat is set on or off. I've even tried removing the batteries. Does anyone know why this might happen?
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0answers
48 views

How can I use a portable A/C unit to cool my clean room?

So, I have built a room inside my shop, a clean room for finish and airbrushing. I want to cool this room as I spend more time in it than the rest of my shop (garage) So, I get a portable unit. ...
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1answer
45 views

Appropriate register for duct size?

So I asked a long-winded version of this question in another thread, but haven't really received any good responses yet. I'm going to condense and try again... There is an 8" duct feeding a 6x12 ...
3
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1answer
35 views

Can I replace my draft inducer blower with a model of a slightly different speed?

My furnaces draft inducer blower sounds like a snow blower running, so I set out to replace it. Finding a replacement part proved difficult, but I found a site advertising a compatible part and ...
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0answers
63 views

Would increasing the size of the A/C duct for my kitchen improve cooling?

As part of an ongoing kitchen project, I'd like to relocate the existing a/c register in the ceiling (which is located next to an interior wall) to the center of the room and upsize the duct (and ...
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2answers
96 views

On a thermostat, are “R” and “Rh” terminals the same thing?

I have an older thermostat controlling an old ass Trane furnace with A/C. It has an "R" terminal and an "Rc" terminal (they are jumpered - see photo). I see references to an "Rh" terminal online. Are ...
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1answer
55 views

AC not cooling using heat pump

I just bought a house and this is my first experience with using a heat pump. I have put in several hours of research and understand how it works but I need someone that has experience to give me some ...
2
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2answers
59 views

Are there optimal positions for A/C and heat register grills to be facing?

I noticed a while ago that some of my A/C and heat register grills are facing the walls and not the room (the insides of the curves on the grills face the walls) in some rooms but not in others. My ...
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1answer
112 views

Connected C-Wire to new Smart Thermostat and Furnace board and still no power

I need help. I've been surfing the internet and have had no luck finding answers to my situation so am hoping for some guidance. I've seen other questions here answered but none that suit my ...
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2answers
66 views

Why do I have to start my furnace manually every morning?

The oil furnace works fine all day and evening, then overnight I have the programmable thermostat lower the temperature at 11pm. But every morning at 5am when the thermostat tries to turn the ...
3
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1answer
50 views

Why would my boiler expel steam when it's set at 180F

So, I have recently had some issues with my boiler (hot water - not steam) system. After hiring some guys to stop by and take a look at it, they told me that the boiler pressure reducing valve, ...
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1answer
213 views

Adding a C/Common wire to HVAC system

So I'm looking for some help in identifying where I can attach a C/Common Wire to my HVAC system, but unfortunately my system doesn't have a control board that I can easily attach a powerkit to. For ...
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1answer
44 views

Why is it taking so long for my A/C to start?

When I turn my AC thermostat to cool, I can hear it click but the outside unit does not start and no air blows inside. Several hours later everything turns on and it works fine. If it turns off, ...
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1answer
27 views

Good replacement actuator?

I have 2 Belimo actuators that control dampers for A/C ducts in my house that the motor has gone bad on. I can't find much info about the model "LM24-T US" so I think it has been discontinued. I ...
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1answer
39 views

Sound proofing HVAC ducts

We have an HVAC system in our house where the duct work is all sheet metal with no insulation on the interior of the ducts as all of it is buried under inches of foam roofing insulation. Works great. ...
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1answer
62 views

HVAC replacement

we just recently purchased an older home- 1978 - 2200 sqft, 2 stories, 2 14x20 returns - one downstairs, one upstairs, 5 ton 10 seer system, 10yr old goodman air handler but the condensor is unkown ...
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2answers
19 views

How can I install Air condiitoning timer

want to install a timer on split air conditoning unit to accomadate my energy plan hours, too many people change the thermostat. could another thermostat be used at the pump, controlling one of the ...
2
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2answers
117 views

How should I wire a Trane air handler & heat strips?

Looking for validation or correction on my understanding of requirements for wiring 5 ton Trane air handler with 20kw heat strips. Of course, I read the label and identified that there are (2) 240v ...
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2answers
78 views

How can I use a WeMo controller on a non-standard outlet?

I have an older A/C unit that uses a 6-15p plug. I want to be able to remotely control the unit with a WeMo, but it uses a 5-15r receptacle and plug. The A/C unit says its rated for 208V, and I ...
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1answer
60 views

Is there a wireless way to cut off the HVAC y wire from my generator transfer switch?

I recently had a Generac Synergy generator installed, which went smoothly, however there was no good way to get the Y wire from my thermostat to the transfer switch and back in order to allow the ...
3
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5answers
166 views

How can I vent a portable air conditioner when there's no window?

My shop does not have central air and does not have operable windows. There is a steel door in the back and cinderblock walls. My landlord is against me cutting a venting hole in either the steel ...
2
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1answer
35 views

Can I use a power gable fan and ceiling louver vents to pull cool air into my house?

I live in L.A. We only have really hot weather 5-10 days a year and it usually cools off at night (outside). I also have a large Gable vent in my attic. (recently added with addition) I would like ...