Lennox Furnace Problems? Start With the Model Number

It may seem insignificant, but when you have a dead furnace on a dark winter night, this issue is not so small: The first obstacle to overcoming Lennox furnace problems is getting your hands on the whole model model number. Why do I say, "whole"? Because the model number you might find in the owner's manual or on other parts of the furnace are not necessarily--are probably not--the complete number.

Manufacturers Other than Lennox

Every manufacturer is slightly different if we were to go beyond Lennox. For example, some numbers will be found on the manufacturer label, often located near the upper right side of the furnace. Of course, in some cases these model numbers are just partial. For most appliances you will have to look on the model tag to get the model number. Where this is can depend on the brand and the model. A user's manual is not the place to get the information you need.

Some manufacturers and HVAC providers will post either an image of where the model number can be found or will provide a description on their websites. With York Furnace, for example, the number may be found in the furnace cabinet in a vented panel. Bryant and Carrier furnaces post a rating plate sticker posted on the upper left-hand side.

Lennox Products

You may be looking for a model number on a Lennox furnace, or maybe you need a number for your Lennox air conditioning unit. Either way, you'll find a data plate with the model number listed. If it's a furnace you plan to repair, you can look at the left side of the interior service panel for the complete model number.

Following are some tips for entering the Lennox model number online, which will help you locate and purchase a part:

• Be careful that what looks like the letter "O" isn't actually a zero "0"; also, it's easy to confuse the lower case letter "l" and the number "1"


• Unless the distributor says so, you won't need to include blank spaces or dashes when you type in the number

What if you aren't able to locate the model number? The next smart step is to call the manufacturer. You can also contact your local dealer and ask for assistance.

The Code

Though it may seem that all the letters and numbers are random, the model numbers for Lennox furnaces actually mean something. If you're the type who's next question is usually, "What does that mean?" then this is for you. If not, you'll probably want see if you can find the model number now and leave the coding trivia for another day.

• G = If you see this letter, the model uses natural gas; this letter is typically followed with a series number


• Q = followed by two numbers divided by a slash mark (3/4, e.g.), this letter stands for unit capacity or drive


• -100 = this means 100,000 BTUs of input in this furnace; BTU stands for British Thermal Unit and is measured in the thousands


• -1 = When you see a dash followed by a number, you can assume that this is model in a series of models, each of which have been modified slightly. The dash number comes last and is very important for finding the right parts for a model.