Hot Air Soldering

[grandta13]

I recently picked up a hot air soldering system for a thrift shop, as it is something that I will probably use, and it was cheap enough to warrant the purchase. My only problem is that it didn't come with any instructions, so I'm not sure how to use it properly. I've seen some videos showing the actual act of soldering with one, but there are things on the unit that I don't know the function of, and I don't want to risk damaging something by using it improperly.
The unit is a 'SMT-1160 Hot Air Soldering System' with a model number of SMT-1101.
There are two things specifically that I am unsure about:
There is a knob on the lower-left side of the front of the unit.

There is a nozzle on the rear of the unit.

I'm not sure what either of these are for, and I will refrain from using the unit until I have an idea (for the sake of safety).

Also, if you have any general advice about hot-air soldering, I would appreciate it.

It's under warranty until this coming Tuesday (5 May 15) so I would appreciate a prompt response if possible. I realise this forum may not be the best place for this, but I figured that some people here would be familiar with it; if necessary I'll repost this to a more specialised forum.

[Tanooki]

This was found using in google: SMT-1160 manual

http://www.theprojectasylum.com/electro ... -1160.html

That may answer it.

The back appears to be the plug for an anti-kink vacuum hose attachment addon.

[grandta13]

This was found using in google: SMT-1160 manual

http://www.theprojectasylum.com/electro ... -1160.html

That may answer it.

The back appears to be the plug for an anti-kink vacuum hose attachment addon.

Thanks. The nozzle on the rear seems to be for nitrogen which will produce higher quality solder joints. I still don't know what the lower dial on the front is, though (air flow control perhaps?)

With this information, I figure it's safe to test. Now I would like to ask how I can test to see if it seems to work properly. I have normal soldering equipment, but nothing that you would normally use with SMD soldering (such as solder paste).

I tested it by desoldering a component from a scrapped PCB and it seemed to work well. I still don't know what the knob of the bottom is for though; I just left it tightened (rotated fully clockwise).