Loud Heater: Troubleshooting & Solutions

Hello,
'My auxiliary heater (Webasto Thermo Top T) has become increasingly noisy over the past winter. The noise is very loud at full power. It sounds like a high-pitched whistling combined with the noise of a failing ball bearing. I initially suspected it was due to a missing air intake hose (which I'm familiar with from my previous gasoline car). However, testing has shown that the problem is not related to the air intake hose.'
Can the burner be faulty? Or could the combustion chamber be making a loud noise because it might be gradually 'clogging up'?
When the SH (presumably a device or system) transitions from full power to half power, or from half power to off, it briefly emits white smoke.

Does anyone have any advice for me? I don't know what else to search for...

Regards, Stacky.

Hmm, unfortunately, the age of the vehicle isn't specified. The smoking could be due to an inadequate fuel pump.
Have you checked the exhaust hose? It tends to rust, which can cause that loud noise.

If this is not the case, try completely shutting down the heating system, disassembling it, and cleaning everything thoroughly.