good afternoon youtube so this is the inside of the gas furnace in my house so this is the
combined gas valve so you've got your knob here off there's the pilot setting and then on and then
here's the control module on top there and so you've got the two th terminals here and then
there's two tr terminals and i'll cut in a picture showing how this valve was hooked up before
before it had one thermostat wire on this side like this one and then the other thermostat
wire was hooked up to the other side this red wire that comes off of the transformer
was just floating right here it wasn't hooked to anything and likewise the
other black wire here was just hanging off to the side as well it wasn't hooked to anything
and the black wire comes from the high limit switch it's a two conductor wire this wire
is hooked to the 24 volt transformer and then it goes up over here to the high limit
and then the other wire comes down from the high limit and like i said this wire was just hanging
and this red wire was hanging and then the thermostat was hooked up across the terminals
on the gas valve so i found a little diagram online that shows how it should be hooked up
so over on the right side there is your 24 volt transformer and then one leg of the transformer
should hook to the tr right down here and then the other side of the thermostat should hook to the th
and then the thermostat should hook here to the high limit and then the my s valve doesn't have
this connection it doesn't have a thtr connection point there so i put in a lego lever nut here to
connect those but so yeah the way this was hooked up this wire here was just hanging
it wasn't connected to anything so let me show you how i've changed that around here see i left
this thermostat wire hooked in here this is in one of the th terminals and then i have the red wire
which comes off of the transformer plugged into the tr terminal and then right here i added a lego
lever nut connecting the high limit wire over here to the thermostat wire so basically you have 24
volts coming in from the transformer goes through the high limit comes back here goes through the
thermostat and then into the gas valve and then back to the transformer and now the furnace works
so like i said i don't use this furnace this is the first time it's been turned on since 2011
and the reason i was turning it on is because i signed up for one of those utility energy audit
programs they're coming out next week to check the furnace make sure it works and i guess they want
to fire it up and then check the carbon monoxide values and make sure all that's good like i said
this hasn't been turned on since the last time they were out the last time i opened this up was
when we opened it up in 2011 to light the pilot light down below there and run it through all
its paces so somehow these wires got all chewed up one of the thermostat wires was broken and
then this wire and the red wire were just hanging out in space they weren't hooked up to anything
the utility guys came out today and they couldn't get the furnace lit so they're going to come back
send in their expert crew next week but i figured i would take a shot at it so i i finally found my
lighter that can reach back you need a really long lighter to get back to the pilot light on this
thing but anyway yeah got a gutter all running the thermostat in the house works at least when
they show up next week they can fire it up and test it out i don't have the heart to tell them
i don't use this furnace but they need to check it off their checklist that they checked it i guess
that way they get paid for paid for showing up and and checking everything out they checked my
tankless water heater and said that passes so they had no problem with the tankless water heater gas
set up there and so they're just going to check the furnace and make sure it's still working right
and then i will turn it off and it'll probably be off for another 10 years but man i don't
know what happened to these wires i have never been in here since the last time i lit the pilot
light let me show you the details on the furnace here this is a pretty old furnace so there's the
name plate it's way oversized this thing is a hundred thousand btu per hour and the house is
about 1200 square feet and it should probably have something like a 35 or 40 000 btu furnace
and there's the lighting instructions it's a real pain to light this thing too
two guys from the utility they gave up after about 15 minutes and then it took me about an hour
to get it lit once i fixed all the wiring so it's a real pain so hopefully it'll pass the test and
and we'll shut it off and button it up for another nine years you've got the four burners the pilots
weigh on the end there and you have to get way in there to get in like that far to get the
pilot light lit it's way on the back side and then the furnace itself is really hard to get to
because it was installed in a closet here and it was probably too wide to put this way
in the in the closet you can only get into right where my hand is because there's a sliding door
so you've only got this much room to get in to work on the furnace and then of course the pilot
light is way as far in in the backside as you can get but this was probably installed sometime in
the mid 70s i'm guessing here's the thermostat this is a really old itt thermostat that's your
temperature setting there it's on there it's off and then you've got your little bi-metal
coil there's your thermometer room thermometer and then that's the bi-metal coil for the thermostat
yeah so that's the old furnace a fraser johnston 100 000 btu per hour just a
massive big unit so that's the one that the air return comes in from the attic
and then i have my combined air return plus the whole house fan is sitting up on top of there
and then i've got a louver up there that i can either block the furnace off or right now i have
it turned open so it it's pulling return air up there over there and then it comes down here
and then the furnace exhausts out the bottom all the vent pipes go out the the bottom of the
furnace and then under the floor to the various registers there's just the 24 volt transformer
up there and then the integrated gas valve and the thermostat on the wall and that's it pretty simple
system and i really don't want to spend any money fixing it i'll put a link to the web page where i
got that little wiring diagram at because i could not find a wiring diagram inside here
it's not on any of the panels so i was kind of at a loss initially because i couldn't figure out
what these wires were but yeah it's pretty easy to figure out you've got the thermostat two
wires you've got the high limit with two wires and you've got the transformer with two wires and then
you've got the gas valve that has two terminals so you just hook everything in series basically
pretty simple system just two switches in series and a transformer and a valve so yeah if you have
any questions about that post up in the comment section below and as always thanks for watching