Is this normal? I have 100 hours on it, it’s heating up a running fine but never seen it this way before. Thanks.
It’s microbrobial growth or diesel fuel algae. Plenty to read up on online.
How old is the unit? You can’t let diesel sit around too long it will grow stuff. Always have a couple of fuel filters on hand. This goes for anyone running a diesel truck too.
You may have gotten some bad diesel. Or it has been a minute since that burner got ran. Or you have never changed that filter. Did you get it after a bad rain. Kudos on the catch though!