Now that we’ve surveyed the system, the first thing that we have to do is shut the system down. But before we do that, we need to make sure that the furnace is in good working order before we begin cleaning it. To do this, simply locate the thermostat in the house, and turn it up to trigger the furnace to kick on.
We then go back down to the furnace, and check that everything is working correctly. Take the front cover off and watch to see the burners kick on. It’s a good idea to keep a pad and pen handy at this point, so that you can take note of anything unusual.
If you find that the furnace is not working correctly, you should immediately inform the homeowner. This will eliminate any recourse back to you after you’ve completed your cleaning. Now that we know the furnace is working correctly, we can shut the system down.
If you value your life, never, ever work on a HVAC system without making sure the power and gas to the unit is turned off. To shut the power off, you’ll need to find the disconnect switch and turn it off. This is usually somewhere close to the furnace, and labeled correctly.
After that, we need to turn the gas off. The gas switch should be easily located at the front of the furnace.