What method to use when cleaning an old wall-mounted garage heater?

Question

I recently bought a home with a detached garage, and within it is an older natural gas heater that I cannot find any information on. It is hooked to the gas line and has instructions on how to light the pilot and operate it, however, I would like to clean it out first because it looks like it has been a very long time since it has been used.

It's about five feet tall, stamped LSC-25 on the front and vents horizontally through the garage wall to outside (metal circular fins).

Who manufactured this heater, approximately when was it made, and how do I go about cleaning it so that I can safely operate it?

---

I finally found the model information; it was completely covered with dirt and dust.

"Gravity Direct Gas Heater / Mfd. by LSC, Inc. Kansas City, MO / 1982"

I live in KC, so that's kind of neat that it was made here. It states that there is an optional blower... too bad it's not installed!

Answer 1

A good way to get started with cleaning it would be these steps:

1. Remove the whole array of front panel grills. It may be a single grill or multiple.
2. Carry grills outside and scrub with warm soapy water. A scrub brush will work well, especially for the grill slots. A wash cloth may work best on the large flat areas.
3. Spray down the grill(s) using garden hose to flush away the soap and loosened dirt. Set grill aside to fully dry.
4. Use a vacuum cleaner (shopvac if available) to clean up the dust, dirt, pet hair, and other debris in the furnace enclosure itself. A brush attachment on the end of the vacuum cleaner hose can help a lot on the irregular surfaces. Once the major stuff is cleaned then a damp wash cloth can be used to wipe down the inner surfaces of the furnace.