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

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1answer
285 views

Air Conditioner woes: water pooling in basement, condensation on ducts, frost on outdoor copper pipe

Can someone help diagnose what's wrong with my air conditioner? The symptoms are: the air that it is blowing is not very cold It's colder than the ambient air, but not cold enough to cool the ...
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0answers
73 views

Can changing the fan speed on a forced air heating system reduce the sound heard in each room?

We recently converted to gas heat. Now, when the heat turns on, there is very loud blowing in almost every room. My Carrier Infinity fan speed is set to "Auto." I was told there is nothing to do ...
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0answers
35 views

Why did my central heat shut down?

I did maintenance and turned on the electric heater switch on thermostat to Central Unit. It came on just fine and warmed up the house and shut off automatically. But it never came on again. The a/c ...
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0answers
31 views

Should my Trane dual zone XB14 be short cycling?

I have a 2 yr old Trane zone dual system and it is short cycling whenever I run the ac side, I called the HVAC installer and he said that is noraml due to the fact that the temperatur is 72 degrees ...
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1answer
253 views

Can I install a humidifier on a horizontal duct?

I have a Honeywell whole-house humidifier (HE360A1075). Can this be installed on the horizontal ducting here on the left? It feels like it's an aluminum box under the tape. This is both gas heat and ...
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3answers
1k views

Why is my power flickering across multiple circuits?

I woke up this morning and went downstairs to find that none of the lights would come on (lights were working fine upstairs). My first instinct was thinking that a breaker had tripped, so I went to ...
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5answers
14k 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 ...
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0answers
27 views

Why is my hydro kinetics system blowing out cold air?

I have a hydro kinetics system that is blowing out cool air when set to heat. Thermostat was replaced when I bought the house a year ago so I don't think that's the issue. Toggle switch is set to ...
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2answers
596 views

At what temperature should an unoccupied house be kept at in winter?

We are moving to a new house and unfortunately we don't have our house sold yet. I was wanting a recommendation as to what temperature to keep the furnace going @. I found a good recommendation to ...
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0answers
60 views

What could cause the heat side of our split pack heating/air unit to stop working?

Our heat side of our split pack unit (runs on propane) come on and will runs little bit but then won't come on again. We can turn it off for a while and then it will run again. What could be the ...
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1answer
146 views

Which is better indirect or tankless hotwater heater

I am in the process of getting my boiler and hot water heater replaced. One company gave me a quote for a Weil McLain boiler and indirect hot water heater. Another company gave me a quote for a bosh ...
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2answers
2k views

Can you terminate more than one common on the furnace C terminal?

TL;DR: Can you terminate more than one common on the furnace C terminal? Background: I've linked a diagram of how my non-programmable thermostat is currently hooked up. I want to replace it with a ...
2
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1answer
272 views

What could cause the furnace blower to come on constantly and no fire in gas burner?

When thermostat is turned up on my hot air furnace, the blower immediately comes on, blowing no heat, had it checked and with some luck the burner fired after about 10 tries of switching on and off. ...
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2answers
122 views

Can a furnace with a variable speed blower be used in a multistory house?

I just had an HVAC guy out to give me an estimate on a new Carrier Infinity series furnace and he said the second floor rooms will always be colder because the thermostat is on the first floor and not ...
2
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1answer
341 views

Could a high limit switch cause the furnace blower to run continuously?

My furnace was running fine. The I noticed that the unit was blowing cold air. Checked the furnace burners and they were off. I turned off the unit on the thermostat and the blower continued to run. ...
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1answer
61 views

How do I connect a 24v air purifier to hvac?

I have a MicroPure MX4 that the previous homeowner left behind new in the box. This is a 24v unit and needs to be hardwired. My question is can I connect the two wires to the terminal where the ...
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3answers
5k views

How can I cut a cinder block wall to run large round duct through it?

When an addition was put onto the house that I own, the previous owner just ran the duct work into the crawl space through an old basement window. I want to re-route the duct work by actually cutting ...
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2answers
60 views

Is it possible to create a better temperature controlling system?

I have a two story 2.5k sq ft house with a varying degree of temperature throughout the house. The main problem is that the air coming out of vents are very weak if almost nil. Only the living room ...
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1answer
68 views

Is this HVAC capacitor dead?

HVAC system stopped blowing cold air today. Last time it did this, we gave it a 2-3 hour break, in case it was over-heated, and it came back. Today, same deal, but no cold air after a few hours. I ...
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0answers
169 views

possible HVAC Selector Wiring Solution?

I moved into my current home last winter. This house has an old zone controller MasterTrol Mark V model Mabs-V-3. UPDATE: just found that all wires connected to M? end nowhere. So I remove all the ...
4
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2answers
994 views

Connection for C wire on Mastertrol Mark V zone control panel

I have spent hours searching the web for information on this 20+ year old zone control panel, which supports 3 zones of Heat and A/C. The thermostat I'm replacing (on Zone 3) connects to T4/T5/T6 as ...
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0answers
25 views

Electric HVAC unit runs and stops randomly

I just turned on my heating unit for the season and it seems to be running and stopping intermittently. I'm not sure if this something to be concerned. This happened last season as well and I called ...
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2answers
103 views

Can I remove the insulation from flex duct

I am trying to fit a 7" flex duct between some floor joists and it would fit better without the insulation. Can I remove the insuluation and just use the plastic part?
2
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1answer
5k views

Why won't my Heil 7000 natural gas furnace ignite?

I have a Heil 7000 gas furnace Model: NUGK100DH12 Serial: L933050100 When we turn it on at the thermostat, the exhaust blower will kick on. We checked to be sure the gas is reaching the unit and ...
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1answer
91 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 ...
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1answer
78 views

Should my A/C compressor come on when I turn only the fan on?

I have a bog standard HVAC system with a Nest thermostat. When I tell the theromostat to turn the fan on for 15 minutes the A/C compressor also kicks on. Is this normal?
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4answers
187 views

Running air handler condensate drain into sump?

The condensate drain from our air handler now runs across the wall and into the laundry sink. This is stopping us from attaching shelving to the wall. I noticed that the sump pump pit is right next to ...
1
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1answer
156 views

How do I reinstall round 6" duct pipe in my basement?

The 6" duct pipe was removed in my basement. I am trying to put it back up, but the pieces will not go together. The pipe is no longer round, and even when i try putting pieces together that have the ...
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3answers
1k views

Is there a trick to getting round HVAC duct pieces to fit together

I have been doing some basic HVAC duct work as part of a remodeling project and I can never get the pieces to fit together without massive amounts of elbow grease and mangling the ends. Is there some ...
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0answers
57 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?
1
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1answer
245 views

Replacement thermostat wiring

I have an American Standard heat pump AC. I'm replacing a White-Rodgers manual thermostat (where I move a switch from cold to heat) with a Honeywell RTH7600 (which will automatically switch from cold ...
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0answers
34 views

Why is my A/C's breaker tripping all the others?

I noticed the A/C wasn't coming on - even the outside compressor - so I checked the breaker and the two switches that the A/C is on were tripped. At this point no other breaker was affected. I went to ...
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0answers
255 views

Furnace not working properly with digital thermostat

I have been attempting to use several different types of digital thermostats to replace my old mercury thermostat, however none of them are able to control the furnace properly. All of them are able ...
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1answer
155 views

New condenser fan motor burned out

AC technician replaced my condenser fan (through a home warranty service). The new fan worked for 5 min and stopped working after that. the fan motor was extremely hot (180F or more) The old fan motor ...
0
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1answer
52 views

Should I add an escape register for added ventilation in A/C duct to reduce condensation?

I have a condensation and drippage problem where my 8" exposed circular AC duct comes out of the ceiling. Above the ceiling is the attic, meaning it gets pretty hot. The pipe comes out of the ceiling ...
2
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1answer
96 views

Is there a reason for an exterior vent not connected to anything?

I have an exterior vent on the side of my house not connected to any piping within. You can look inside and see wood/concrete/insulation into the cavity between the basement ceiling and main floor. ...
2
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1answer
110 views

Can a problem with heater stack liner cause outside chimney mortar to crack and fall out

I had "high-efficiency" furnace installed in 2009. In 2011 chimney required full grind-out and repoint job, and chimney saver solution was applied to prevent water damage. Service lasted only 18 ...
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0answers
63 views

Which should I do first? replacing furnace or resurfacing concrete floor?

I'm going to get two things done in my basement soon (by hiring professionals), but I'm wondering what the right order of operations is. One task is to replace the gas furnace that sits near the ...
18
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1answer
12k views

Humidity Levels

What is a healthy and safe humidity level that I should try to keep my house at?
-1
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1answer
44 views

What is wrong with my air conditioner

I have been using my air conditioner on and off all summer. The weather hasn't been really that bad this year. But now that the weather is reaching high 80s, my air conditioner decides to die on me. ...
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5answers
14k 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 ...
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3answers
1k views

Electric panel distance from windows and/or gas service entry

I can't find anything specific anywhere else, but what is the minimum distance a main electrical panel can be from a window when the panel is mounted on the outside of the house? Additionally, is ...
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2answers
112 views

Home inspection requires exhaust to attic exterior

We have sold our 1995 built home. One item that needs to be addressed is "Bathroom fans vent to attic and need to exhaust to the exterior of the attic to prevent moisture condensation in attic." I ...
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1answer
622 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
264 views

Furnace filter inserted backwards, will this cause permanent damage?

Just found out that my wife changed the last furnace filter and inserted it backwards. This was noticed after the ac was not cooling the house very well. I went outside and noticed that the coil ...
0
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1answer
158 views

How to connect a DIY thermostat to the HVAC System

I am building a DIY thermostat similar to this blog. I want to connect it to the HVAC system of my home. How do I do that? I found this post which is very informative but doesn't completely answer my ...
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0answers
22 views

Need to run a “C” wire to thermostat but control board has no “C” [duplicate]

I am looking to replace a thermostat with one that needs a C wire... which my current thermostat does not. I have some extra wires in the thermostat wiring that are unused... so I went down to the ...
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1answer
105 views

A/C Unit Has Leaking, Has Ice Buildup

Came home yesterday to find that the house was burning up and the thermostat had automatically switched itself to heat... in the summer! We didn't know what was going on, and assumed some sort of ...
1
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1answer
170 views

What could cause a heat pumps line sets to be the same temperature when running?

The symptom I'm dealing with is that the heat pump system isn't cooling as much as it should. Tested it today, was about 79°F inside and outside; system was blowing air at about 73°F. ...
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6answers
19k views

How often should I run a bleach and water solution through condensate lines?

How often do you need to run a bleach and water solution through the condensate drain lines (of a heat pump) to keep the bacteria away? What are the recommended parts (e.g. 1 part bleach, 10 part ...