Thank you in advance for your help. I have an old octopus AFCO forced air furnace. Never had a problem until a few years ago, replaced thermocupler, and has worked fine until now. I work nights, and came home the to the house feeling a bit cold. turned up the t-stat and waiting a few minutes...nothing happened. So went down to furnace and noticed the screw in t15 fuse was blown, changed it and furnace fired right up.

So I came home yesterday, same scenario. went down to furnace. cranked up t-stat. fuse still intact. Nothing. ran to hardware store to purchase new thermocupler thinking that was it. changed it out..nothing. breaker never tripped either. since it being an old furnace it has the old dial t-stat with no option for fan to see if getting electricity. I went though the procedure listed on the furnace. hold down button on box that the thermocupler goes into to reset it. all works fine and dandy. Pilot was never gone out, thermo tip it glowing red, so I know that its being hit by pilot flame.

What the problem seems to be that the there is no push of gas to ignite the flame. Almost like there is no gas being fed in main line. the line for pilot is fine though. the pilot line feeds off on the main gain line. Long story short, burner is not firing up. I tried crossing red and white lines going into t-stat to see if the burner would ignite, still nothing. Any help is much appreciated, as noted in post, my daughter has chronic lung issues from complications at birth. In other words, the colder it get in the house, the harder it is for her to breathe. I know the furnace needs replaced..but that's not really in the budget.

 

Welcome to the forums.

That sounds like possibly a millivolt ignition system but you mentioned blown fuse and now no operation.

That AFCO (American Furnace Company) furnace dates back before 1969 when the company name change from AFCO to Singer American Furnace. Over 45 years old.

It may not be in the budget to replace it but at least have it professionally checked for heat exchanger issues. A carbon monoxide detector near the sleeping quarters is a given also.

Probably going to need a model number as I'm not familiar with what you have there and I'm not sure if anyone else will be either.

 

the fuse was blown about a month ago. replaced that. worked fine. so 1 month later (today) is when I started experiencing problems. ill post model #. should the r and w wires going into thermo spark when touched togather though? It seemed odd that that they didn't. I want to almost believe that the t-stat is the issue, could that be? ill actually post pics of the furnace and id plate.

 

 

That is an ollllllld BASO switch. Haven't seen one in a few years but along with pushing it down to prove pilot, doesn't it move to the side to ignite the burner? If not, check that solenoid that the wires from the BASO run to and see if there is a springed push button on the underside. I've seen that style also.

 

the actual box it self move, no? it just has the reset on top that you push in. it seems to functioning properly though because one the pilot is lit it shows as on.

 

Memory fails me because that one is obsolete. Maybe since the pilot has proved, press down on the switch one more time. Also, look for the spring button on solenoid before the burner. It's either getting 24 volts or not.

 

not sure what the solenoid looks like?

 

trace the wires coming from the BASO switch down to the switch (solenoid) right before the burner on the gas line coming in. I have had them hang up before. If it doesn't open there will be no burner. It's on the left side of your pic looking down on the burner compartment. If no spring GENTLY give it a rap with the handle of a screw driver handle. Your furnace can be retrofitted to get rid of all that old stuff, but most will try sell you a new one because frankly it's seen it's best years.

 

two wires trace back to the part with the yellow top and a third traces back to the plate in the second picture, wire is the bottom of the two.

 

which is the solenoid...sorry if the question is dumb.

 

Ok, still pleading old agies but I still think the BASO has an activator once pilot is proved. Either you have to re-press the button on top to activate the solenoid or slide it to the right. Else, it's time to dig out a volt meter and track it down. Read the instructions carefully that is printed on the cover of the BASO and make sure you haven't missed anything. I tried to zoom and it was blurry.

 

I honestly give up on it guys...I called and had someone come for an estimate. they do financing. 2600 for a 95 percent efficiency. everything included. I will probouly just pull the trigger on it.

 

You will be dollars ahead. Sorry that I couldn't get you up and running but it's a matter of time before you were going to have to pay for a service call that would be a good down payment on a new one.

 

that's what I thinking...I knew this day was coming, lol. I figure my monthly savings will pretty much pasy for it within 3-4 years.

 

Just make sure you find a reputable company. Any fool from Craigs List will put something in for you but disappear like a cockroach when the lights come on if you have a problem. Talk to neighbors, family and friends before making a snap decision. Buying electric heaters to get by is cheaper than a snap decision out of necessity.

 

Sounds too good to be true for a 95% furnace, let alone changes to ductwork, t-stat, electrical, etc.

If your ductwork looks like this:



...real forced air will never work right without a new duct system.

 

thanks for the info guys. im glad my furnace doesn't look like the one in the last picture, lol. I have what they call a low boy. I only have 3 ducts running off of it and one that blows from the furnace out into the basement.. My house is on the smaller side if you know what I mean. It is a reputable local company, came to the conclusion that I will need around 60k btu to get the job done. I have 2 more companys coming today to give estimates. Need to get it done though, its 12 degrees outside and the space heaters are running like a mother...if you know what I mean.

 

Gravity = no blower

Hopefully the 2 ducts feeding the house have smaller branch lines.

 

Tuffy, can you take a pic of your current system so we can see the duct and furnace from a distance? Sounds like ducting might need to be addressed with no more runs than you have.