Why it is happening?
So you have had your fireplace for a while and are noticing a thin residue that is building up on the inside of the glass. Don't worry, this is a normal thing. The foggy appearance may be due to the combustion of the gas each time the fireplace is in operation (calcium and sulfur deposits on the glass), or from the "off-gassing" phase that occurs in the first 15 hours of operation which cures any residue from the manufacturing process. The important thing to know here is that this is a natural occurrence, and will happen over time.
How often should the fireplace glass be cleaned?
This is dependent on your particular model, fuel source, and weather. Although some technicians may recommend that you have the glass cleaned twice a year based on regular usage, this can change upon preference. Some people may have an optimal environment and need not clean the glass for years. When you see that film develop on the inside, it is time. No operational issues will occur with dirty glass.
How to clean the glass?
If you do not feel comfortable cleaning the glass yourself you can always hire a technician to do so. If however, you only want to spend the money on a cleaning product for it, continue to read.
The manual is always your first resource when doing any maintenance. In this, you will find out how to take off the glass on your fireplace, and whether it has hinges or not. This is the first step behind turning off he gas source including the pilot light.
Make sure that wherever you put the glass, it is in a safe place. Too many times does someone lean the glass up against something only to have it slide down a crack. Who knows if your fireplace is still in production, this makes finding new glass next to impossible.
The next step is to use a non-abrasive cleaner similar to the one by Imperial. Then following the instructions on the bottle, pour about 2 tablespoons on the glass. Spread it around using a soft dry cloth and let it sit for required time. Buff it off in a circular motion and then you are done!
Refer to manual for all steps and regular maintenance
1. Turn off gas and pilot light
2. Remove the glass and VERY carefully place the glass somewhere safe
3. Using a soft cloth, and following the instructions on the back of the non-abrasive cleaner linked above, pour 2 tablespoons on the glass and rub in a circular motion.
4. Let this sit for required time.
5. Buff off in a circular motion with a soft dry cloth until residue is gone.
We have linked a video below to help for those who love visuals!