1977 (Old) Lennox Gas Furnace Overview [G8D2-82-3] 

We bought a house now from 1965, still the original furnace in it, also from Lennox. We plan on keeping it so long we can. Just do proper maintenance on it. That's built to last.

Solid old furnace. As a licensed gasfitter in alberta i am a huge proponent of the old standard efficient furnaces, they are way more reliable than the newer ones and their efficiency is great. The parts are affordable and that offsets any cost of replacement parts for the higher efficiency units. Whats going on with all those blocks of wood under the blower assembly? Looks like someone used the wrong blower and shimmed it. Heat exchanger looks good but the best indication of a cracked heat exchanger is done through combustion analysis. Keep that old beast till shes not safe to run. Itll never let you down on a cold winters day

We really appreciate this video! We recently purchased a home with two 1979 lennox units and pilot lights were out entirely. Of course we had no idea what to do. Thanks to your video we learned how to start the pilot light! We have heat!

I remember my childhood home having one of these until 2002. It started banging and making horrible noises but lasted over 20 years and was great. Replaced with a high efficiency Carrier Infinity two-stage variable that is still going strong 20 years later and has never needed any work other than regular maintenance. A great product is a great product.

The fire looks fine. Like Google User said, the flashes of yellow are little bits of dust and dirt burning off. You see a similar effect on other gas appliances such as a range or water heater. What you don’t want is a “lazy” yellow flame. It is bright yellow and flickery like a candle flame.

I've got one just like this but bigger. Yours is definitely cleaner than mine!

I got you beat! Mines a working 1959 Lennox furnace!

We got a house built in 1888 that was remodeled in the 70s with a Rheem gas furnace. I cleaned and checked it with an inspection camera. I repaired leaky supply and return ducts in the crawlspace and put in a smart thermostat. There is a floor vent for combustion air, but this old house is leaky, which is especially evident on windy days. I put smoke and CO detectors in every room and will maintain the furnace as we remodel and improve the efficiency of the building It does produce great heat at 80 percent 80,000 BTUs output with two burners, made in Fort Smith, Arkansas. I plan on replacing the gas system with a new blower and hydronic heat exchanger in the crawlspace heated with an air to water heat pump with a solar thermal water tank, and a separate split system in that attic exhausting outside to heat the upstairs.

Simple and reliable,great furnace ,my is39 yrs old and still work great.

These style of Lennox furnaces are actually still quite efficient even today have a 1972 rheem furnace thats very similar and it works just fine why replace when the current unit is still good enjoyed the video

I've got the same one, and it's just needed routine maintenance and filters. No issues yet after all these years in service.

I had the same furnace in my home. The heat exchanger was cracked so I had to replace it. Note: the filter on my furnace was called a hammock style filter and wrapped around the blower and motor oddly enough It was in the shape of a big U. I replaced my furnace with a two stage 96.9% efficient (non modulating) carrier furnace.

Thanks for the memorys. We used one like this ourselves for 25+ years. I remember it being noisy when the fan kicked in. We called the heater the USS Titanic Boilers. You could just see all the gas it took to fire that thing up and it would run that way for many hours. $$$ We replaced it with a hybrid heater with AC. Heater runs on gas or electricity and with the solar panels we can save huge amounts of money. You program heater with your local prices for energy and the system will pick the source of power based on what source is cheapest. You really don't know when its working in that you can bearly hear it running. It was a big jump in technology between the different heaters. Like 1920's compared to 2018, just saying. Old heater was like yours a 1976 model. When you change yours out don't skimp, just go for it and get the best one you can afford and you will not be sorry. Great video.

Had the same furnace. Reliable as hell. Problem with these is the pilot uses a lot of gas (~10%) and the furnace uses ambient air which causes negative air pressure which sucks in cold outside air that must be heated. Overall efficiency is then 49%. The 90%+ unit will have direct air vents in and out, no pilot and a 2nd heat exchanger. I've had mine 15+ years no issues at all. I've saved almost 10k in that time. Install was 2600. Air seal your house, upgrade poor insulation, replace windows. These 3 upgrades alone reduced my heating energy requirements by almost 1/2.

I remember having one similar but had 4 burners that was original to my parents house in 1966.. Was a beast and all it ever needed was the draft diverter hood replaced. When it got replaced it found a second home and continued service in a garage somewhere.

Mine's from 1967 and it still works perfect

Best indication of a cracked heat exchanger is seeing the Crack. In this furnace the Crack is in the back of the heat exchanger where the chamber narrows. We use mirrors, lights, scopes, and combustion analysis. A pro is worth the money if skilled.

The flames look better than on your other video. The left burner looks misaligned - crossover tubes should line up and stay that way. If it gets worse you may get delayed ignition. You can't tell if a furnace is properly tuned by looking at the flames; yellow can just be caused by dust and you can have perfectly blue flames but high co production or too much excess air. You would need to call a tech with the right tools to check fuel input and combustion. (the fuel input u can actually check by clocking the gas meter, but can't check combustion) You can't tell if the heat exchanger is cracked on this model by checking for disturbances. You need to get in there with a flashlight (or snake camera) and check back of every cell where it starts to curve for cracks.

This actually older....this is a G-8 model, which is designated by the type of vent hood, gas valve, pilot, and gas valve. It WAS built in May by the E designation.the 63 was the plant number.

You are a Man of Culture, I can tell. I have an old Singer Furnace (Yep, "Singer") that almost identical to yours. Work Horse. I have been studying and overhauling my furnace for a few years myself. Pro Tip - Your ribbon burners (I have 6) are missing the air adjust caps. I found that the tin lid off of Beeman Pellets .177 fit these ribbon burners perfectly. Cut out the same pattern hole and now you can adjust for the blue tip flame. Find three screws to hold the position and your Gold. Let Me Know if you want to sell that Honeywell V810A 1012 Gas Valve - I'm shopping for a spare. 🤣"Yup, in the old days things were better built, simpler, and planned obsolescence wasn’t a thing."

After re watching this video i also noticed your left most burner could use a little twist to the right so the flat flame spreader burners line up properly. Thatll help with it lighting off easier

I was expecting to see a Lennox whisper heat or a pulse lol glad its not!!!

I remember having a Trane furnace of this type prior to summer 2013. I was very young at the time but I remember it working very well when it was there. I could set the thermostat 5 degrees higher and it would bring it up in 15 minutes. The only reason it was ever replaced was because the compressor outside died and we had done an addition to the house so more capacity was needed

I can't speak for this model, but on newer ones if the exchanger is cracked it is usually evident by flames blowing backward over the tips of the burner. This can also happen if the passageways in the secondary exchanger get corroded shut (if you even have a secondary). The tubes are narrow and it happens with a condensing furnace. I know all this the hard way. The repair man wanted 5000$ to fix it, or 10,000$ to replace the whole furnace. Luckily I found out the whole thing is basically modular and comes apart with a single socket. The only pitfall being they used generic electric connectors in this furnace (a Hayes model) so you must carefully mark or photograph each connection. The rest was just a major unbolting/bolt back together operation and 1400$ in parts for both exchangers. Because you can't really tell if its a crack or clog till you take it apart, best to just replace both. Obviously do this at your own risk because if you mess up, you can flood your house with carbon-monoxide (the seal between the burners and exchangers is the crucial bit). After the repair, I replaced the batteries in all 3 of my CO detectors. A CO detector costs about 15$- your life is priceless so its a good idea to have them anyhow.

Nice ....my furnace is a 1975 Stewart Warner..... still going strong....😂

What is the life expectancy of a unit like this? I've got a Lennox furnace just about like this. My neighbor said not to let anyone sell me a new furnace and keep this one until it dies (the heat exchanger goes out for instance) as they are simple units and thus simpler to fix and more reliable. I know that it is 37 years old I know for sure and figure it's more like 49 years old and was put in the house when it was built in 1972. Works like a champ.

You might want to pull the slotted control valve out, under the main knob, and put some 'silicone' grease on the sides.. Remove the old stuff with a cloth and alcohol, and wipe a thin 'new' coat on the slotted cone.. The sticking was because the old Si grease was dried out..

My house has a Payne furnace from 1978 and she's still chugging along. They don't build things like they used to.

My friends that they live in Windsor Ontario they use to live in there old house on I think it is dot avenue but when I was in childhood I had saw there old furnace and it was a Lennox and it was pretty big and it sat in there basement after when the house was built there original house was built in 1973 before 1977 but the furnace that they had was made in 1973 to 1974 and the model to there furnace is VR800c-1190 and the pilot light in there furnace was glowing bright yellow and I had saw the pilot light glow in the heat exchanger when the light to the furnace room is off and completely pitch dark

I have almost the same one just a cousin model, i turned it off for the summer at the breaker box and went to turn it back on and nothing happens..any tips? The motor on the fan is ice cold so im thinking its not getting power..i got the pilot light lit and nothong

These are best

Built to last

What if the pilot light went off, but gas valve keeps releasing gas? Is there any flame sensor that can shut off the gas valve when there is no flame detected?

i remember as a kid ours would bang as the fan would start up and bang again a little while after the fan turned off, forget what my dad said it was so im at a loss as to what was going on

Hi my client just purchased a house and the furnace was working prior to the electric cut off. When we got the electric back on and the furnace pilot and fan turns on but not the burner. Any suggestions

Don’t replace this furnace unless you have too. Too many idiots in the comments wanting to get you a replacement because they are tree huggers

I have one of these also in Calgary. Mine is slightly different. I can’t for the life of me find the air filter to change.

I have one made 1975 .i shut the gas and electricity and clean it from dust..when i opened the gas and electricity it didn't work ..i didn't see flam from the gad ..how i ignited ?

Are you still running this unit? Mine is a bit newer, 1979 model with electronic hot surface ignition - no pilot light. Also I have some thoughts of replacing it. But with "ain't broke, don't fix it" mentality, I still keep it running. I just do basic maintenance on mine - cleaning dust and flame sensor rod every season to keep it running. Very simple & super reliable unit, I doubt it if the newer ones are as good..

Does anyone know how to get the top front panel back on fully? I put the bottom one on first that has the filter access but can't get the top panel to snap closed at the top.

we have the same furnace is it really doesn't have a filter in the return air intake area? I just move from this house I don't know nothing about the furnace I leave in an apartment for so long. and do I need to oil it , one more question do I need to turn off the flame in summer time cause I wonder if they cost me while I turn off the furnace but the flame is still there

I have a very similar one, the pilot is lit but the furnace won't light, and suggestions where I can go for help.

My house has a similar OLD Lennox furnace. The city inspector approval date was April 1978. I clean it every year using compressed air to get the loose rust particles out of the heat exchanger. I will replace my windows and add more insulation to the attic instead of replacing this 44 years old furnace. I am thinking to install a cold temperature heat pump for cooling the summer and heating in the winter down to -10°C. I know the the heat pump electrical heating element to supplement the heating at below -10°C. Any one have using a old gas furnace to supplement the heating instead of using electric heating elements.

Where is the filter located? You should have pointed that out. I need to change my filter

I am very stupid in furnace. Do you know how to replace the filter

You have a fan. :) Mine has a thermocouple powering the thermostat & main gas valve. No external power. Guess what just failed? Choice of 3 so I need to search more.

My daughter just bought an older home with this type of Lennox furnace. We not see where to put a filter in. There does not appear to currently have a filter. Do you have a video on how to change the filter?

How do you remove the burners to clean them?

A gas fitter monkeyed around with my wires any chance you can show the wires on the gas valve and in the box?

Can you please make a video of this furnace running a full cycle without commentary?

Where are the oil caps that need oiled once a year?

Is there a filter that needs to be changed?

A link to the other video would be nice?????

Wondering if you can make a video of its A/C unit part? I have almost thesame old style Lenox and hear dripping sound along the vents but cannot find where its coming from. HVAC person came and insulated the coils at the bottom part of the unit that we can see dripping and sealed it really good but we still hear dripping from the vents. I'm just a regular owner of an old gas furnace and I would still like to DIY this if its possible to save money. Any help would be very much appreciated. Thank you.

The high efficiency ones will not have the life that one did .

hello InternetDude ! i have a similar furnace like your (my model is GH6D-100M, IDENTIFIECATION NEMBER IS GH6D-100-M-2). It runs very reliable but now the burner and blower doesn't work ( no heat ) but i check the flame is still lighting as always, and last season the blower or fan makes sound clunk clunk every time the heat is on. The controller is show the heater is on but no sound of blower or heat come out. Do you know anything about it ? What wrong is that ? Thank you for your time.

These heat exchangers had S curved heat exchangers that would crack. Yours could be cracked and should be replaced to avoid carbon monoxide problems. You would have to cut the back of the furnace out to know. The gas valve you have does turn on slow. Looks like it is running ok.

Thanks of the video. I have almost like this one (G8Q3 model). Would you happen to know where the heat sensor is located? My furnace is short cycling and I think this may be the cause.

What is the gas valve brand name? and model number? thank you.. I am also looking for info for the G12Q3-137 lennox furnaces.

I need help with an Old Lennox furnace It is a G12Q3-110-1.. the pilot light is lit, but when the burners come on.. it all shuts off need some help here

Where is the heat/flame sensor located?

What thermocouple for a g8

Hi. I have a G8D2-82-2 (must be older lol) and the motor seized. I'd forgotten this always happens in the middle of night and throws smoke and stink throughout the house, never during the day. Got the motor out, bought a new compatible one from an engine rebuilder (they don't rebuild that type of model anymore) and of course the wiring colours are different. I have white, black, white with red stripes, white with yellow stripes, and the green ground of course. The new motor tells me what it's wires are for, do you have any idea what the furnace's colour coding is?

Do you have the link to the first video? I want to know where to place the flame of the pilot

Hi, I had a similar furnace, we replaced the motor and the bearing on the blower last year, but recently there's a shaking noise whenever the heat lit on, it looks like the noise came from the blower, the shaft that connects the bearing wobbled when it turns, would you know the problem? Could it be fixed? Thanks.

Hi I have the same furnece but not working when it is below 22 degree and when I set it up over 23 degree the burner cycle is more than an houre tnx

Why do u not show how to actually turn the pilot light dial? That's the whole issue with this type of furnace.. what's the point if filming if your not gonna show a step by step guide

Would you happen to know where I could find a complete wiring diagram for a Lennox G12q3-110-6. Not the logical schematic.

G8Q3-90-2S Lennox what’s the proper filter size for this old furnace 1980s

That inspection was from 1971 not 1977, if you look at the year it's a 1 not 7

we have a LENNOX furnace. I cannot locate the filter.The gas pipe is right in front of the whatever openable lids I find! The number on the furnace is PGH 32-855.Where do you think it would be located?

Help! I have thesame exact furnace. When we moved in a few moths ago, furnace still works but tonight the pilot is not even igniting, no fire at all and its cold tonight! any DIY that I can do until some I can get some help in the morning? thanks bunch!

I have something that almost looks the same as yours only mine is g8q3-120-1 and everytime the fan kicks on it makes a sound, but after a quick 5seconds it's gone. Base from my research i found out my blow motor is giving up? I'll appreciate your response.

I think I have exactly the same furnace. The blower seems not working, I changed the filter and the breaker is not tripped. What could be the problem? Please help.

Yeah, replace it soon. OK, I have a question. Why is it in the bathroom? Or why is there a toilet in the furnace room?

Where is the heat sensor on this model?

Hey man i have similar furnace and the flame is gone. How do i lit it?

I work in HVAC I don’t think the flames look great I would get someone to come and look at the unit. those were nice units! The oldest furnace I ever saw was a 1955 ge unit it had major cracks in the heat exchangers. I only replaced one of those 1977 Lennox units I have seen many live on.

How do I turn off the light? It's summer and still lit

A cracked heat exchanger on that unit would be a strong odor of burning dust type smell. I lived in an apartment with that same model number unit and one very cold winter month I went to use it and I noticed the odor. When I called maintenance they came out looked at it ran it and said everything was fine. Later that night I took the burners out And shown a flashlight up inside the part where the flame goes and sure enough I saw two cracks in the bottom and side of the heat exchanger

I got a 1972 Lennox just took a crap after 52 years

I have an old Lennox G12Q3-110-1. it is very old. I can light the pilot light, the furnace kicks on and runs for under a minute and it all shuts off!?.. why? it's getting cold

i have a 1973 lennox, i replaced the pilot burner and thermocouple with a new unit and afterwards the pilot light would stay on just fine , but the furnace will not turn on at all now, any advice would be appreciated. it was working a week prior but the pilot kept going out, so i replaced the pilot burner and the thermocoupler and now the pilot stays on just fine but it does not turn on all all. i checked the breakers, i switched out thermocouplers twice but now it doesnt click, doesnt turn on, it does nothing, only thing that works is the pilot, and its very strange to me because the only thing i touched on it was the pilot assembly, and now it wont turn on all all. id appreciate any advice you could give, thanks.

Why cause the gas dont blow out de pilot is good but the gas no come out the blowet is workin but the gas valve no open

you ever blow into the furnace and watch the flames go woosh?

Orange means incomplete combustion and a risk of higher carbon monoxide output. I'd recommend having a monoxide detector in the garage and near a vent in the house.

I'm having mine ripped out at this very minute.

How do you get at the filter to change or clean it? I have one of these and need to clean the filter

Mine works great but it needs to be oiled . It is squealing

6:46

Were you able to get your left hand burner properly situated in the notch in the heat exchanger? Thank you for deleting that john whatever the hell his last name is hateful comments. Obviously the guy doesnt know anything about furnaces. Plus he drives a crappy old nissan maxima and listens to charlie puth 😆🤣😂 lets keep your old furnace rockin for another heating season!!!

No offense, but you obviously have no real working knowledge of furnaces which can be very dangerous and should not be making these videos.