How to clean Atwood Water Heater Burner Tube?

[D44]

So just to close this out - yes it was a spider web. Shop took off the burner tube and cleaned it out.

Next time I will try the long pipe cleaner hack mentioned by 85MH325 followed by my compressed air. If that burns up the thermal cutoff I’ll take the burner tube off myself.

May just order another package of thermal cutoffs to have on hand just in case.

Thanks to everyone for commenting.

Walt