Webasto ThermoTopE Start Noise

Hi!
"Since I installed my auxiliary heater as a new part 5 years ago, it makes a very loud, deep noise for the first 40-60 seconds when starting. However, it's not a mechanical noise, but rather sounds like a resonance in the exhaust system. Of course, a muffler is installed. The Webasto hotline suggested that changing the CO2 content might eliminate the noise, but unfortunately, it doesn't. Once the flame has ignited, it runs perfectly quietly. But it's only during the ignition phase..."
Has anyone had a similar experience, and perhaps a solution? Otherwise, it's been running perfectly reliably since I bought it, and the error memory is clear.

Dirk.

Hello,

That seems to be normal, as mine does the same thing.
It doesn't really bother me.

Axel.

It's a resonance noise. As long as the noise doesn't occur during normal operation, you don't need to worry. For the warm-up phase, there was a solution: drilling a 3mm hole in two specific locations in the exhaust pipe to dampen the resonances. However, it didn't always work, and I no longer remember where the holes need to be drilled.

Adjusting the CO2 content can certainly improve the situation, but it can also lead to the 3D printer not functioning correctly when it's warm.

Leave it as it is, even if it doesn't sound very nice.

Rolf.

Okay, so it seems like it doesn't really help. Too bad. Still, thank you for your answers.

Dirk.

Hi,

"My auxiliary heater makes the same noise. It doesn't really bother me. At least that way I know what my auxiliary heater is doing (whether it's starting up or already running)."
A friend of mine has had a similar noise from a parking heater for over 6 years: no problem.

Regards,
Sure, here is the translation of the text from German to English:

"Micha"

My auxiliary heater initially made a noise, and then it eventually stopped working because the combustion chamber was clogged with soot.

I wouldn't worry about it. Mine has been making those noises since the very first minute of operation. My father's one does too.