Home Improvement Stack Exchange
Home Improvement Stack Exchange

Questions tagged [furnace]

The furnace is part of an HVAC or central heating system used to generate heat. Typically this is done with gas, a heat pump, or an electric element. For hot water and radiator based heating, use the boiler tag.

For more general questions, see , , and

Related components include:

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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 there such a think as thermostat-controlled,…
Vebjorn Ljosa
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What is causing the pilot light to go out with a loud clunk?

On particularly windy days like today, the pilot light in my furnace likes to go out. To try to confirm it is the wind blowing out the pilot light through the flue, I set up a camera and recorded this footage: Pilot light going out with a clunk The…
Resorath
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Why is this pipe in my garage filled with concrete?

Any idea why this water pipe going into the ground in my garage next to the furnace and water boiler tank is filled at the upper end? What's its intended use? If I want to use it in a effective way, how to re-open it?
qazwsx
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How do I identify the C terminal on my HVAC?

How do I identify the C terminal on an HVAC, furnace, or boiler? If the terminals don't have a screw labeled C what should I look for on the wiring diagram? What steps should I take if a wiring diagram cannot be found or if it indicates that a C…
BMitch
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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: Pictured below, an Aprilaire humidifier control unit…
The Other Steven
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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 efficiency of the unit?
Dave
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Is it possible to upgrade A/C to a heat pump by only replacing outside unit?

I have a standard southern California tract home that was built in 2010. It has a Carrier gas-fired furnace, Carrier 5-ton A/C, and a smart thermostat. I'm slowly upgrading the major systems and replacing gas with electric wherever…
ThisOneGoesToEleven
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How many wires can be connected to the C terminal at the furnace?

I'd like install a new Wi-Fi thermostat. The old one didn't have a C-wire but luckily there is an unused wire on both sides (one coming out of the wall and one at the furnace not connected yet), so I am going to use this unused wire as the C-wire.…
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How can I audit my furnace?

I want to keep track of when my furnace is on, with an eye to reducing how much energy I use to heat my house. I could compare it with weather data (temperature, wind speed, precipitation). I could see what it saves to turn the heat down when we're…
Jay Bazuzi
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Should I insulate steam pipes in the basement?

I have a steam-radiator heating system. The furnace is in the (unfinished) basement, and the steam-carrying steel pipes spread out across the basement ceiling before going up into the rest of the house. Should I insulate these pipes in order to…
Vebjorn Ljosa
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How much energy will continuously running a furnace fan use?

We have a bi-level (tri-level? There's a small entry way and utility room, then an upstairs living area and master bedroom and a downstairs living area with bedrooms) in mid-Michigan. The downstairs is naturally quite cooler than the upstairs, but…
Peter Tirrell
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What does this device on my new furnace do?

Can someone please tell me what this is? I had a 35-year old oil furnace replaced recently and the new furnace is obviously more complex and has many safety features the old one didn't. I've looked it over and understand what all the new devices…
Carey Gregory
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Why are furnace/central AC blowers so inefficient?

I can buy a ceiling fan from Home Depot capable of moving 5,000 CFM of air for about $50, and it uses a mere 50-60 watts while doing it. By contrast, most furnaces seem to have blowers that operate in a much lower CFM range but use humongous 1/2 or…
iLikeDirt
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What kind of drain pipe appears to be clay?

The photo below shows a venting stack that was disconnected. The stack runs from the basement to the attic and out through the roof. Which means it's perfect to pull new water, gas, and vent lines up through it. It was probably part of a gravity…
MFMauceri
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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 is an additional cost to this relocation, of…
Cathy
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