How To Gas Furnace Basics Maintenance and Servicing

If you have a forced hot air system then you most likely have a Gas Furnace in your home. Gas Furnaces are the most common and economical method to heat your home. They are also really easy to maintain when compared to their Oil Furnace counterparts which normally require a professional.

If you live in a rural community gas furnaces are available even if you don’t have a natural gas line to your home because with only a small change in your burner you can use propane instead of natural gas. This will also require an above ground propane storage tank be installed on your property and deliveries of fuel will be made by truck.

Gas is both efficient and clean so unlike oil heat that normally requires cleaning of the furnace internal parts once a year you can go many years without a professional service call when you use Gas Heat.

On the other hand Gas furnace ducts often double as delivery for air conditioning which is both a benefit but also means a lot of dust will build up in your ducts requiring regular changes of your filter. You will also need to monitor other parts of the system for good working order and perform general maintenance but most of this can be done by a home owner.

I would say dust will be your biggest problem. If you purchased your home new then you may eventually need to clean your feed and return lines if you purchased your home and it is over 10 years old I would suggest that you get your ducts cleaned as part of your moving in expenses. Its important enough to reduce that problem right from the start.

Once your system is operating properly and cleanly you want to keep it that way.

You should change your furnace filter regularly however if you have an extended and unregular cold or hot period of time the air in your home will be circulating much more often. For instance this January was extremely cold and I found that I had to replace a filter that was not much older than 3 months old. Since the cold isn’t letting up I expect I will need to change it again before spring is fully here and we get a rest between the heating and cooling seasons.

How Old Is Your Gas Furnace

This is very important to know because there have been really dramatic improvements in Gas Furnaces in the past 15 years.

New Gas Furnaces are extremely efficient some are 95% efficient when running at their best. An older gas furnace will normally require an actual chimney or insulated / double wall pipe to expel hot air from the burner. Newer gas furnaces transfer so much of the heat to the heat exchanger which heats your home that spent burner air can be forced out the side of your home through a PVC plastic pipe.

Needless to say if you are sending so much heat out of your home you are losing money and heat. Additionally your furnace BTU’s are probably over rated. Meaning a more efficient heater using less gas which is smaller could probably heat your home much better.

That is the first thing you should know. Look for the presence of either a 6 inch galvanized vent to a chimney or 2-1/2 inch PVC pipe and you will get a general idea of the age of your furnace and then look for a decal or plate on the furnace that gives you an actual build date.

Also to be noted sometimes feed or supply air is fed to the burner in PVC pipe if the room air is not enough to supply the burner so don’t get confused about that.

What if you can’t find a build date? You can normally find a build date but if you can’t look for a manufacturer ID and then the Model and Serial number of your furnace. If the furnace company is still in business email or phone them and they can tell you.

When you contact the manufacturer tell them that you need a service manual for your furnace. Many better companies offer this online in a PDF File for free and this document will be of extreme help to you in the future to track down and diagnose problems.

It should also give you part numbers, ratings of parts like the blower motors so you can purchase generic replacements and operation information for general use.

I strongly suggest you get a Service Manual and not just the generic product literature which is only a few pages of introduction and sales information.

Final Note

This is a basic how to not a repair how to.

If you follow this how to you should now understand what you need to do as an owner of a Gas Furnace to prepare yourself and it for long term operation.

You should get a copy of your Service Manual and read through it.. yes actually read it because when you need it you don’t want to be looking at it for the first time you want to say to yourself .. hey i remember reading about that the answer is towards the back.. and then actually find the answer.

You should understand that your ducts can and will fill with dust over time and will eventually require cleaning no matter how good a house keeper you are.

That you should find your furnace filter location, get its size and type and then purchase a 3 pack of replacements so you will have them on hand. A clogged filter can actually shut down your furnace and if that happens at 2am on Sunday morning its better to have a $3 filter ready to install vs paying for a weekend overnight time and a half visit from your repair guy.

Finally you should know what type of burner vent you have. Do you have an actual chimney that goes through your roof or is your furnace vented through PVC pipe to an outside wall and you should inspect them and make sure they are clear of debris like bird nests for a chimney or bushes around your side wall vents.

Your next job is to write down all the model numbers you can find on your furnace and air conditioner if you have one integrated and then find the manuals. Then hop on the web and price out some of the replacement parts just so you have a basic understanding of part costs.

In other how tos we will cover actual repairs of specific problems in detail.

Remember if you don’t feel up to it have a service tech come out and teach you how to change your filters or even how to find it. Ask a relative or ask a parent but get started learning because it is one of the most important parts of your home.