A lot like a ping pong ball in a fuel tank...
Not really because most pickup tubes are filtered with a "sock"
But these heaters... No so much. Trash on the bottom of the pickup tube and it is over like @Guyfang mentioned.
Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!