Why is Furnace Maintenance Important? | Ask This Old House

foreign [Music] what have you done now well I thought I would make a really solid case on getting heating appliances service you know it's a crazy idea once a year right yeah in this case it's a gas-fired furnace this is the Baseline in America how most people Heat their houses and it's pretty simple to look at as a device it has a return air right here and a blower that pushes air up through the unit up into the duct work and goes out to heat or cool the air in the building now inside that air is also the combustion side so if you look right here on the front side there's gas burners right a gas valve and a fan in this case and what it does is it burns into a thing called a heat exchanger this is a sealed unit that takes all those flu products heats up that heat exchanger the exhaust that is Caustic and filled with bad stuff carbon monoxide carbon dioxide will go out either to a chimney or to outside right and that air passes by the Heat changer touches it but doesn't mix with that bad air and gets heated up and that gets pushed throughout the house and we're good to go so a proper service call that will happen with any decent company it'll come that you'll as a checklist and what they'll do is they will check the gas pressure coming in from the supply the gas pressure at the gas valve itself and that determines how much gas mixes down here at the burners these burners will ignite into the heat exchanger they'll also check the safety devices wherever they are here here and elsewhere to be sure they're all operational they'll do a combustion test with an analyzer and that'll go in and it'll see temperature carbon monoxide carbon dioxide knocks and you can read a lot into that you can see if it's dialed in right if they don't they'll dial it in right they don't want it burning too hot they don't want to absolutely clean right and there's plenty to be learned from this you really can't do without some sort of combustion you can't just go yeah I think it's fine yeah it's an important device in the building particularly if it goes out but it's also can be dangerous if you don't take care of it and do you suggest people have this done once a year on I do I do this is one thing that you really want to run so this is heating only right there could be a heating cooling combo right so this is one this is a this is the Baseline furnace this is the basic furnace this is the more elaborate furnace but I've shown you the coil on top of you know this is air conditioning same thing happens fan comes back wait let me just hit you up for a second you're telling me that the gas and heat all happens down on this everything everything the same is over here and you just put this box but on top is this air conditioning section okay so now what should also be done on every service call is to change the filter even homeowners should be changing the filter you'd be amazed the number of people that say ah oh that filled this clogged and they take it off and leave that naked to let air come in and guess what happens that air comes in it doesn't probably bother the heat exchanger too much but look inside this this is the cooling coil see how fine these fins are okay so now what happens is if you're blowing cat hair and dust and lint up in the back side what's going to happen is going to clog the air conditioning coil gotcha and all of a sudden you can impede the airflow not only for the cooling but for the heating as well and if this gets clogged up if then it's you got to take it apart because it's blowing from the back side and there's you got to take carefully where the vacuum brush you got to get in there without bending the fins and make a coil cleaner that can do something but it's not going to clean it if it's completely clogged with grease and everything else it means you're going to have to really take it apart clean it like crazy you really can't have enough filtration the more filtration the better you know this is not enough I don't think this is what you should have as a baseline ounce of prevention gotcha and if I don't do this what's the risk I lose efficiency it doesn't turn on when I want you certainly lose efficiency but I brought this one along because I just I just went to a an HVAC contractor's yard and I said hey you got any friends we just took this one out yesterday look at this so this is a furnace that had never been serviced they wasn't their customer and so if you look down carefully right here there's cracks on every one of these sections which means that the carbon monoxide every time the gas burner was on that was supposed to be coming out here correct was leaking into the living space the only reason they actually discovered is they were so hot this summer they decided to call this company to have them add air conditioning they finally had a combustion analysis and they literally had saved their life that could have been deadly could have been it's important it really is important so had they done a regular service call I noticed that you you know you checked fluid I would have picked it up I would have picked it up I would have picked it up in the Airstream do they test that sure you go in here and you make sure it should be absolutely this clean beautiful where you see any Co you know something's cross-contaminating between it well if they're not all convinced now that should convince right there call a pro this one's we you don't do it yourself you need the devices call a pro get it all right thank you Richard thanks for watching this whole house has got a video for just about every Home Improvement project so be sure to check out the others and if you like what you see click on the Subscribe button to make sure that you get our newest videos right in your feed

Channel: This Old House

Views: 63,208

Keywords: This Old House, Home Improvement, DIY, Construction, Ask This Old House, Building, heating, Richard Trethewey, Kevin O'Connor

Id: 1MiO4e3qbSk

Length: 5min 0sec (300 seconds)

Published: Sat Mar 25 2023