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

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5
votes
6answers
22k views

How can I prevent my HVAC condensate drain line from freezing?

Last night, my heat (forced air) suddenly stopped. Today, a plumber figured out that my heater is 90% efficient, produces lots of condensate, and the drain line had frozen. We went outside and saw ...
0
votes
2answers
66 views

What could cause the blower in my furnace to come on?

Ok my blower just turned on, my propane furnace and it's not in operation due it being summer. My thermostat is set at 65 and the room temp is 78. The heater never actually fired it was only the ...
1
vote
2answers
1k views

What are my options for venting my oil boiler?

I have a small New Yorker AP-U (480?) boiler that is currently vented to a large flu in my house's chimney. I want to install a wood stove in my house and I'd like to use the chimney to vent it, which ...
3
votes
3answers
18k views

How much less power does a three-phase A\C unit use as apposed to a 220v 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 ...
4
votes
4answers
4k 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
1answer
464 views

Why is my furnace blower running at low speed?

My Payne gas furnace (PG8UAA 42091) automatically shuts down after it lights and burns for two minutes. It then gives a 33 fault code. I've done some research and some testing and have narrowed the ...
0
votes
1answer
24 views

Fan coil wiring problem with new thermostat

I'm trying to upgrade to a new line voltage thermostat. The new thermostat has many more connections, including three fan speeds. My current system has a manual fan switch on the wall so all I need ...
0
votes
2answers
114 views

What are the possible reasons I am not getting cold air from my air conditioner?

my heat pump outside is working but my central air conditioning/heating unit in the garage makes a hissing sound or faint sound of water running. There is air coming from the vents. The very last time ...
7
votes
2answers
3k 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
votes
0answers
33 views

Estimated cost to add dual zone A/C units that have been ripped out of a foreclosure? [on hold]

In regards to a 3300 sq ft 2-story foreclosure in FL. Built 2005... They ripped out both A/C units, one was in the garage and one was in a closet upstairs. The house has all the duct work, only the ...
1
vote
2answers
129 views

HVAC Duct options in floor joists

I will explain what I would "Ideally" want. I would like the HVAC in the basement ceiling to Not require a soffit. Plumbing seems possible because the holes for the most part will be small enough to ...
4
votes
4answers
5k views

Why would my Goodman gas furnace start but not stay on for more than 2-3 minutes?

I've got a problem with my 15 year old Goodman furnace. It starts w/o problem, inductor begins working, hot surface ignitor lights up and ignites the gas. Then the main blower starts working and the ...
3
votes
2answers
79 views

What is the smell coming through my HVAC system?

If I leave the furnace fan always running for an extended period of time (to circulate and filter the air), when the central AC turns on there is a not-so-fresh smell that is emitted through the ...
1
vote
1answer
33 views

Is my HVAC system unbalanced?

I bought a home back in August and the previous owner had a new 3-ton HVAC system installed. Basically right now the HVAC is located in the upstairs hallway, and the way the duct is set up is there ...
1
vote
1answer
34 views

alternative to packaged unit downstairs

House built in 1922. Never had central air. Heated with hot water boiler and rads. 2 stories, 1569 sq ft. Salesman recommended split sys upstairs and packaged sys down. Only appx 22 inch clearance in ...
1
vote
4answers
83 views

My house has electric heat, built in 1969. How can I save $. Are solar panels the way to go, or is there something better out there?

I'm not sure which way to go . My electric bill is nuts. I have a fireplace and it helps, but it only heats one room. Are there any good solar panels on the market? I thought about geothermal but I ...
0
votes
0answers
32 views

What if my Trane 3 ton 13 seer heat pump is unable to generate enough heat to reach the set point on the thermostat?

The unit turns on when thermostat temperature is set higher than room temp. It blows cool air for several minutes and then the emergency heat kicks on and warmer air comes from vent. This lasts for ...
0
votes
1answer
521 views

Can I have a separate thermostat for a wood boiler?

I want to wire a separate thermostat for my outdoor wood boiler so that just the furnace fan will come on without the propane kicking on. This is a Coleman furnace. Is this possible and if so, how ...
5
votes
3answers
127 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 ...
13
votes
2answers
1k views

Can I run a central air conditioner in the winter?

What happens if you run a central air conditioner when it's below freezing outside? Is this expected to work? I know, it sounds crazy, but that's because you don't live in an overheated New York ...
1
vote
3answers
757 views

How can I heat up my apartment to kill bedbugs in Southeast Asia?

I have a bedbug problem in my apartment and I want to fix it myself with heat. (I do not want chemicals sprayed around.) Apparently, getting a room to 140 degrees for two hours is sufficient to kill ...
2
votes
1answer
2k views

How can I prevent heat loss through heater/air conditioner wall units?

HVAC experts out there... I live in Wisconsin and it gets mighty cold here! I have a condo with 2 wall units that are used for both air conditioning and heat. My heat bill in the cold winter months ...
1
vote
1answer
80 views

Why does my shower run out of hot water quickly?

My shower runs out of hot water quickly. Initially the water is perfectly hot, then it starts cooling after a minute or so and we need to adjust the lever to maintain the temperature. Somewhere around ...
0
votes
0answers
14 views

Why does the A/C come on downstairs when heat is on?

I just moved in to a 2-story house. It is zoned upstairs and downstairs. If I turn the downstairs thermostat to OFF and the upstairs to COOL, the HVAC in the attic comes on, the outside compressor ...
0
votes
1answer
36 views

What could be causing a moth ball like smell?

We have a smell like moth balls in bedroom of condo. Moth balls and camphor smell coming from heating unit in bedroom.
1
vote
3answers
97 views

Transfer Grille Baffle

I just finished building a new home and as part of the Energy Star rating transfer grilles were installed above each of the bedroom doors to allow air exchange when the doors are closed. The problem ...
3
votes
3answers
9k views

Why is my furnace blower noisy when it starts?

The blower of my furnace makes a loud noise every time it starts. I understand that a large fan and the movement of large amounts of air will produce some noise. What I am puzzled by is the noise that ...
3
votes
3answers
323 views

What material is allowed for a furnace room ceiling material?

What types of material, other than drywall, are acceptable by Ohio HVAC Code for the ceiling of a small furnace room which will: Have return air ducts (only) passing through it to attic space. Butt ...
0
votes
2answers
144 views

How can I move hot air from a cathedral ceiling to colder bedrooms?

My main living room has a 25 foot cathedral ceiling with a ceiling fan including a staircase going to the second story bedrooms. The thermostat is situated in this space. There is space to install a ...
0
votes
2answers
440 views

No electricity going to thermostat

Our old thermostat is working but I want to change to a new one (nest thermostat). I have two exact HVAC unit at home. I change one it works but when I change the second one it doesn't work because ...
0
votes
2answers
997 views

Installing Honeywell WiFi Thermostat

I am trying to upgrade to a programmable thermostat. I bought the Honeywell RTH9580 with WiFi. I can get power to the new thermostat and get the fan running. However, it will not work when the fan ...
0
votes
0answers
14 views

What could be causing my goodman furnance to not work?

My furnace starts, than the blower motor runs constantly, but trips out on roll out limit switch. The air inlet and outlet lines appear to be unobstructed, but when it shuts down there seems to be ...
1
vote
0answers
34 views

Can't find the circuit board of my HVAC system

I'm trying to install a wireless thermostat for my church building's HVAC system. Currently there is no C wire, so I tried to see where the circuit board was so I could install one. I couldn't find ...
4
votes
0answers
33 views

Is it possible to install a whole house humidifier away from the furnace?

My building is essentially a single extremely large room. It's a 25'W x 45'L x 20' H concrete box, with an open mezzanine over the back 1/3 of the box. The HVAC system is gas-fired forced air, ...
2
votes
2answers
55 views

Can I replace a high limit switch myself?

Thank you for the answer, can I change this myself or do I need to get the HVAC company to do this? I have turned off the breaker in the panel box so that it does not come back on. What is the purpose ...
2
votes
3answers
494 views

Does my crawl space need venting

I have a crawl space under my main entrance of the house. It's about 3' tall. I added a heat duct because the floor at the entrance was always cold. So my question is do I need to vent the crawl space ...
0
votes
1answer
476 views

How can I add a C-wire to a Venstar T5800 thermostat?

I am trying to replace my existing thermostat. My old thermostat has: Rh, W (coming from the heating unit). Rc, Y, G (coming from the AC unit). On the Venstar T5800, I can map as follows: Rh+Rc ...
1
vote
1answer
12k views

Should I add a return air vent in a refinished basement?

We are refinishing our basement, and are nearing competition. The walls are drywalled, and the ceiling is dropped. There will be about 500 sq ft of finished space, including a full bathroom, and ...
0
votes
1answer
776 views

why does my heat pump wiring diagram show 7 wires going to the thermostat but the thermostat only says it needs 5?

Here is a link to the wiring diagram for my heat pump. The thermostat that I am planning on buying has the following terminals C, G, Y, O/B, RC, R, Aux, E, and L. The instructions say to jump the RC ...
0
votes
0answers
41 views

Baseboard heat not keeping up

This is my first winter in my house which was built in 1991. A Navien CH-240 that provides both hydronic baseboard heat and hot water was already installed. We have two zones, upstairs and downstairs. ...
0
votes
1answer
74 views

How can I determine what grade air filter is appropriate?

I'm trying to figure out what kind of air filter is appropriate for my house. My local home warehouse store stocks over a dozen options. The primary difference between them seems to be Microparticle ...
0
votes
2answers
38 views

Can I remove a furnace compartment vent that's obstructing roof repair?

There are two vents going up to our roof, one is the normal vent from the furnace exhaust straight up to the roof. But right next to it there's a second vent pipe, a little larger and single wall. ...
0
votes
1answer
493 views

What could be causing my Lennox furnace to blow cool air?

My Lennox outside furnace is blowing cool air, not hot even when the burner is lit. It takes 3 times longer to heat the house than it should. I just had the draft motor replace about a month ago and ...
2
votes
2answers
391 views

Can I cap the air return in my unfinished basement?

I noticed today that there is a massive air return in my unfinished basement. The opening is about 2 meters from the blower, and as large in diameter as the return duct coming from the upstairs. This ...
1
vote
1answer
3k views

How to diagnose a broken Aprilaire humidifier (Model 600)?

I have an Aprilaire Humidifier Model 600 (or maybe 600M) mounted on my furnace. The humidifier is not turning on (i.e. letting water flow over the filter) when the furnace is on. The below images ...
0
votes
2answers
133 views

Gap between 6“ dia wall thimble & 6” hvac pipe

I bought a 6" dia aluminum wall thimble to vent my 6" dia hvac steel exhaust pipe through to the outside. However, the diameter of the 6" thimble is actually 6 3/4". How do I effectively insulate the ...
2
votes
2answers
2k 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 ...
1
vote
1answer
36 views

Damper close to main supply vs damper close to the register end: what is the difference between the two positions?

For the air duct that feeds a room, what is the difference between installing a damper at the register end and installing a damper close to the main supply duct?
13
votes
9answers
15k views

Do thermostat-controlled, auto-adjust HVAC vents exist?

The residential forced-air HVAC systems I have seen are controlled by a single thermostat in one room. One has to manually adjust the vents in order to adjust the temperature in other rooms. Is ...
0
votes
2answers
51 views

HVAC system setup

I have a builder building me a home right now and we had agreed to set up two separate heating and cooling systems for the first floor and second floor of the house. I raised the issue the other day ...