(Heating, Ventilating, and Air Conditioning) For questions about installing, repairing, and troubleshooting HVAC systems.
1
vote
1answer
13 views
How to find areas where heat/coolness are lost?
I live in a 2-story rental townhome (basically an apartment with 2 stories). Our central air/heat system isn't really the best at keeping the upstairs and downstairs the same temperature whether in ...
1
vote
2answers
67 views
Should we use A\C in the unused second story of our home?
We don't use the second story of our home. Is it better to shut off the air conditioning completely upstairs to save money, or keep it set but at a higher temperature, such as 78-80 °F?
1
vote
1answer
51 views
What is a quieter alternative to gas forced air heating?
My small 1BR apartment has an old gas furnace that works great, but costs my landlord too much to insure. He plans to install gas forced air, an in-unit upright furnace. I'd love to suggest a ...
1
vote
3answers
153 views
Would a normal ethernet cable survive the conditions in an air conditioning vent? [duplicate]
I am currently renting a flat, which prevents me from making modification to the walls. However, I still would like to run ethernet cables between rooms. Between all the rooms, there are AC vents ...
1
vote
2answers
59 views
Should I insulate air conditioner coolant pipes?
I recently replaced some rotted insulation on the coolant pipe that runs out of my AC unit and into the evaporator in my house. When cleaning inside the actual AC unit itself I noticed that the ...
0
votes
2answers
111 views
What could be causing this leaky evaporator problem?
My apologizes if I do not know the correct terminology for some of the parts. I will try my best though.
We have a Trane A/C system that is causing us a headache. It is causing water damage in our ...
2
votes
1answer
43 views
Does outside air conditioning compressor fan run all the time?
Had some electrical issues with an air conditioner and after I rewired it, I noticed that the fan was stopping every 30 seconds or so. Is this fan supposed to shut off when unit is running?
0
votes
1answer
97 views
How can I get my thermostat C wire connected? [duplicate]
I have an older furnace, on the switch block I have Y,C.W,R and an unlabeled screw that connects to the shut off it looks like. I need to hook up a thermostat that needs the C wire. I have a spare ...
2
votes
1answer
55 views
How do we replace an old 3-wire thermostat with a 4-wire one?
How do we replace an old 3 wire thermostat with a 4 wire one? We have an AC/heating unit, but the wiring for the thermostat does not have a yellow wire.
What can we do?
0
votes
1answer
87 views
What to look for in a new furnace
I've recently been told that my furnace, which is about 20 years old, is on it's last stretch and that I should consider replacing it now rather than waiting for it to fail - potentially at a very ...
0
votes
1answer
52 views
How effective is a heat pump for AC and a heat pump/furnace for heating in New England?
We currently have a central AC unit and oil furnace. The AC is broken and the furnace is old, so we are thinking of replacing both sometime in the next year.
We are considering replacing the AC with ...
3
votes
3answers
127 views
How can I repair these rusty electrical connections?
When I turn on my air conditioner at the thermostat the vents kick on but nothing outside. Also the last time that it worked it took a few minutes to get going and was pretty loud. I checked the ...
3
votes
0answers
43 views
Why won't the fan run independently of the air conditioner?
I have central air and heat, with a Nest thermostat. My system has Y, G, R, C and W wires coming out of it:
which are wired into my Nest like so:
In between, there is a splice where the C wire is ...
1
vote
4answers
167 views
What could be wrong with my air conditioner?
My outside fan (compressor?) will not turn on. I have a week or two before the weather gets warm so thought I would try fixing it before I hire someone.
Symptoms - I turn on the air. The blower ...
0
votes
2answers
231 views
What could be wrong with my A/C unit?
I just installed a new compressor fan on my outdoor A/C unit. Before the fan went bad, it was working fine and had just had its annual service check (the service guy said the freon was fine, ...
0
votes
1answer
49 views
Exhaust venting into air return?
In the condo (2 story semi-detached townhouse built in 2004) I rent, the main bathroom has an interesting vent system.
When turned on, 2 fans are activated. One is a booster of some type and ...
3
votes
2answers
324 views
Why does the pilot light go out when the furnace is running?
Every time the furnace fires up, it blows out the pilot light. Sometimes it will run a full cycle and blow out when it shuts down, and sometimes it will blow out about a minute into the cycle.
We ...
8
votes
8answers
4k 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 ...
2
votes
2answers
209 views
Does a whole house humidifier go on the intake or outlet of the furnace?
On what side of the furnace do I install the tank of the humidifier (the warm side or the return air side)?
8
votes
1answer
146 views
Should I relocate the HVAC unit in my attic?
I have had a couple of estimates to replace our HVAC system and one contractor says he would relocate the system to a more central location in the attic. One says there is no need to relocate. There ...
1
vote
1answer
79 views
Why won't my propane boiler's pilot stay lit after replacing the thermocouple?
The pilot on my propane boiler won't stay lit for more than 30 minutes even after replacing the thermocouple and outside gas valves. The inside gas valve was replaced two years ago. Service people ...
1
vote
3answers
104 views
I need a multiple-switch light switch which can't all be turned off at once
I have a 4 switch (I think it's called "4-gang"?) light switch on the wall.
It's not connecting to lights though, but to AC vent doors. Now, these AC vents must never all be closed at once. Meaning, ...
1
vote
1answer
40 views
Plug HRV (Constructo 2.0 ES) into power bar?
Would there be any issues if I plugged this HRV into a power bar? I have this unit (says 200 watts of power) which is in the closet of the master bedroom and plugged directly into a wall socket.
I ...
6
votes
4answers
731 views
Heating/cooling system recommendations for this small house?
I will soon build my first house and I need to choose what type of heating/cooling system I'll have installed. I know very little about this and I'm seeking recommendations, ideas, suggestions, etc.
...
1
vote
3answers
136 views
How can I add ventilation to my basement office?
I have a finished basement with an office, guest bedroom and bathroom. All about 700 sq ft.
I work 12+ hours in the office and really need to get some fresh air circulating by extracting stale air. ...
2
votes
1answer
503 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 ...
3
votes
1answer
71 views
How do I install a bathroom exhaust system?
We are set to close on our house in about three weeks and one of the problems that the inspector noted was that the vent in the guest bath vents into the attic (never going outside) and the master ...
0
votes
1answer
40 views
How can I add a relay to the manual control for my HVAC unit?
I have a self standing HVAC unit that has a control panel with manual buttons. There is no thermostat. Eventually my goal is to create a relay that can be controlled via IR/RF so I can install a Nest ...
0
votes
1answer
40 views
Why isn't my thermostat working?
I have an old Lennox (gas heat only) thermostat. There are 3 wires coming from the wall. Black, yellow and a light blue color (could be a faded green or an old dirty white).
The thermostat wouldn't ...
5
votes
2answers
224 views
Is it safe to install a sconce light box inside a return air space?
In my finished basement, the space between one section of studs is being used as a return air duct for my furnace and central air.
Here is a picture, looking up from the vent at the floor level:
...
1
vote
2answers
99 views
Why is my furnace blower coming on so early in the ignition process?
Alright, I installed a new furnace a few months ago and have begun to notice an issue with the blowers. When the furnace first starts up, the exhaust blower should turn on to expel gas, then the ...
1
vote
0answers
60 views
How do I size a wall sleeve for a through-the-wall air conditioner?
We are shopping for a through-the-wall air conditioner. We do not currently have a hole in the wall with a sleeve in it. We are trying to figure out what sleeve to buy.
The air conditioner we like ...
3
votes
1answer
57 views
Does code require the gas line to be replaced when replacing a furnace?
I replaced my 45 year old (still working) original furnace with an American Standard furnace about 5 1/2 years ago. Now I have a gas leak; the Nicor technician sealed a connection in the gas pipe ...
6
votes
7answers
1k views
Should I apply car wax to the outside of my air conditioning unit?
Through different conversations with family members and friends, I have been told that it is good to apply a coat of car wax to the outside of the air conditioning unit frame. I assume that this is to ...
2
votes
2answers
53 views
Why does the pilot light on my Vermont Castings stove keep blowing out?
I bought a house with a sunroom heated by a Vermont Castings gas stove with a problem the HVAC/stove repair person hasn't solved by replacing the thermocouple, valve($$$) and taking apart and ...
3
votes
1answer
76 views
How do I provide proper fire protection in this situation?
HVAC guys are running a vertical duct (supply and return) from my basement to my 2nd floor attic. It will run adjacent to an exterior wall and will eventually be enclosed in a drywalled-in vertical ...
4
votes
1answer
71 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 ...
2
votes
1answer
2k views
How can I connect two indoor ductless A/C's to one compressor?
I have one Hitachi i-clean split AC 2ton unit installed in my home. I want to connect another indoor ductless unit to the already installed outdoor compressor. I only need to use one indoor unit at a ...
1
vote
2answers
85 views
Is it safe to install a heating duct register in the ceiling directly above a home entertainment center?
We're in the process of getting bids for central heating and one of the conundrums is where to position the registers. Due to the layout of our living room (and style preferences of my significant ...
7
votes
1answer
1k views
Why are almost all of my house's HVAC floor registers placed near exterior windows?
My current house is a single story built over a crawlspace and all the HVAC registers are in the floor. In all of the larger rooms, at least one (and usually more) register was placed near an exterior ...
10
votes
3answers
3k views
Is running ethernet cable through an air return allowed under US code?
I'm looking to wire up the second floor of my house and the cold air return provides a convenient, straight run from the office to the utility room. Is it safe and within code to run ethernet cable in ...
9
votes
4answers
6k views
Does lowering the blower speed of a forced-air furnace lower its efficiency?
My gas furnace has two options for the blower speed: MED, and MED-HI. It had been set on the higher speed, but that was too harsh, so I lowered it to the slower speed. Does that have any impact on the ...
2
votes
0answers
64 views
Does each zone in a two-zone heating system have its own pilot light?
I have two zone heating, in the basement and upstairs where we really live. The pilot light is lit downstairs, but the heat isn't working upstairs (the air is not getting hot). Is there also a pilot ...
2
votes
1answer
80 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?
1
vote
1answer
122 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 ...
8
votes
2answers
470 views
What does a Summer/Winter switch on furnace air ducts do?
On some of our furnace ducts, there is a switch/valve for Summer/Winter or S/W.
What does changing this switch/lever accomplish?
Can bad things happen if I forget to switch it?
Bonus question: ...
0
votes
1answer
152 views
How can I use a separate transformer to provide a C wire to my thermostat?
I Purchased the Honeywell WiFi Prog Thermostat to replace my Round Digital Honeywell Thermostat.
I have separate Heating and Cooling (Heating is a Weil McLain Boiler for Hot water baseboard and Hot ...
2
votes
0answers
31 views
Should I install the jumper on my new limit control?
I needed to replace fan and limit control (White-Rodgers, model 5D51-35), because the fan switch was broken (fan would constantly run) and heat would not stay on.
I took a picture of the control, ...
10
votes
11answers
4k views
How can I increase the heating efficiency of a forced air system?
What are some DIY ways to increase the efficiency of a forced air heating system?
Please answer in Community wiki fashion: 1 tip per answer.
Edit:
As @Jay Bazuzi pointed out, tips can also include ...
0
votes
0answers
89 views
Why isn't water running through our radiators?
We had a plumber in today to bleed our rads. He also changed the batteries on the thermostat and fiddled around with the boiler. Since he left the temperature has dropped dramatically and he's refused ...
