I have a small house (900 sq foot upstairs, all heated and 900 down, but with only 200 of it heated). The furnace is a Janitrol (model ?), installed 12 - ? years ago (I bought the house 11 years ago and the furnace was "pretty new" then. I have a programmable White-Rogers thermostat.

A few days ago, I started noticing an intermittent problem. I'm not home a lot, so the thermostat is set to 59 at 10:30 pm, and to warm to 63 at 7:00 am. It's then supposed to dial back to 59 at 9:00 am and stay that way until I get home at 8:30 pm.

My bedroom is downstairs, and my office upstairs is right next to the cold air return, so I often hear and am familiar with furnace sounds/cycles. And something is "off" lately. Sometimes in the morning, the furnace will come on earlier than set (because the temperature has fallen below 59 in the night). Sometimes it comes on as scheduled....

The ignitor lights, the burners and then the blower comes on. While the blower is still running, the burners come back on again and run, then shut down. During this period, there is a series of metallic clicks. The entire sequence may happen several times. Then the furnace shuts off. However, the house has not warmed up to the desired temperature. (I trek upstairs to make sure...it's gone up a couple of degrees but not the 7-8 that it should).

If I go back downstairs, take the cover OFF and push the switch located just behind the cover, the ignitor will light, burners come on, etc. SOMETIMES this will solve the problem and the furnace will run until the house is warmed.

But a few times lately, I've come home during the day. When I try to turn the heat up, we go through the same "morning" problem....

I've read some posts about looking through a "peep hole" to watch for flashing lights to diagnose/troubleshoot, but I can't find a such place.

I am not afraid to get dirty or to try things on my own if I think they are reasonably within my comfort zone. I do need to try to troubleshoot/fix this on my own if it's a relatively uncomplicated issue. But I cannot afford to make it worse, or to do what is NOT going to help. I am undergoing treatment for a serious medical problem with no insurance, so I really cannot afford to pay an HVAC tech to come out to fix something I reasonably could do myself.

I do know the difference between the ignitor and the flame sensor. I know where they are but not how to remove/replace them. And some sites say to clean the flame sensor with steel wool, others say NOT to.

I know this is probably a LOT of info...some of which might not be needed. But I'd like to not do more (or less) than is required to fix the problem. Any help/advice would be SO appreciated!

I have no advice on the actual problem, but did you know that most gas & electric companies will come do a free inspection if you're having furnace problems? You've got nothing to lose by calling customer service at your power company and asking... at worst, they don't offer that service and at best, it's something so simple that it can be fixed during the inspection- most likely, you get the time and expertise of a certified inspector and a good diagnosis of the problem to work with, at no cost.

I had the same problem about 3 years ago. If you know where the flame sensor and the burners are then I suggest that you use steel wool on the flame sensor first. You may also feel comfortable taking each burner jet off and running a pipe cleaner through it - the exact manner of releasing your burner jets is impossible for me to tell you so you could wiggle them a bit and see if you can figure out how they release. I'm not recommending this if you aren't willing to possibly screw up. It's just that I've watch technicians clean the parts before and it isn't terribly complicated, it is just a bit intimidating since a screw up can cost a repair visit.

The bad news I have for you is that in my case, which sounds surprisingly similar even though my unit was a different make and model, it was a relay within the electrical patch panel that went bad. This is the location on the front of the furnace that ties the thermostat wiring into the furnace system. In my case it was that the solanoid valve (part that regulates the gas flow) was not being opened properly because either the relay at the wiring was faulty or the solonoid part itself was clogged up with residue. Unfortunately, there was nothing they could DIY clean about the part because it is an electronic piece for the most part, but the part only cost around $80 and I had a friend do it for tip.

Unfortunately, it did take him awhile to determine the exact problem so there were a few visits before the problem was resolved.

Try cleaning the ignition sensor first, that was the first impulse of my friend BUT it didn't work. Then, unfortunately, I think you'll need a certified technician because I imagine it's a similar problem to mine.

Welcome to our pool. I know we can help you with most of your problems.

Never randomly clean the flame sensor. On some units this is OK, this could damage others. Cleaning a thermocouple is OK but they are not used on that much on newer units if at all. This could be a whole subject in itself so I won't go there now. Ask, and I will tell you how they work.

If this reset button you are pushing is near the flue vent, then this is the back draft preventor.

This keeps bad combustion gases from entering the house. There are ways to test this but not for amateurs.

USA for your location does not help figure out you problem. If you live in a rather cold climate and you have a brick and mortar chimney, the chimney is getting cold during the off cycle and when it goes to start, the combustion gas hit a wall of cold air causing the hot gases to back up and trip the back draft sensor.

Other possible cause is a blocked chimney. I have found bird nest, dead birds and squirrels in chimneys and flue pipes.

Let’s hope it’s not the worst case scenario. Broken in chimney liner. Not as bad as it sounds. Contractor would clear the obstruction and install a stainless steel liners.

If this is the case, a reputable contractor can advise you better as he can "Lay Hands" on the problem.

Yes, some control boards have a blinking light to indicate fault but not all and when they do, they don't cover everything. Mostly a lock out do to ignition failure. If you turn to power off to the furance and back on, this will clear the code and restart the furnance. If it keeps locking out, call for service. This is not a DIY project.

Hope this helps.

Addendum to my previous post. Read and heed.

"Goodman Janitrol 350 Degree Flame Rollout Limit Switch,
Part #B13701-54
The limit rollout switch pictured below are found on many Goodman, Janitrol and other name brand furnaces. These switches are usually located in several places around the outside of the burner box. The purpose of the limit rollout switch is to stop the furnace from operating in an unsafe condition. When excessive heat (350 degrees or more) is sensed by the limit rollout switch, the rollout switch breaks the circuit in your furnace so your furnace will not operate. These prevents a fire or unsafe condition in your furnace. You can manually reset the rollout switch by pressing down the pink button that is located in the center of the switch. If your limit rollout switch trips it is a good idea to have your furnace inspected by a qualified Heating & Air Conditioning technician. You probably either have a stopped up flue, heat exchanger or a leaking heat exchanger. Any of these conditions present a health hazard (possible carbon monoxide poisoning condition or fire) and this should be taken care of immediately. I would strongly suggest that you turn your furnace off until a service technician can look at your furnace. Never by-pass or wire around a limit rollout switch. Several of you have asked me to have these listed on our site. I have accidentally broken a few of these taking the wires off while cleaning furnaces, so I decided to list them on our site. Below we have a picture with an opportunity for you to purchase."



When you do call for service, they will more then happy to sell you a new furnance. They may even use the carbon monoxide scare. Get a second opinion from a recommend company.