If you find oil-fired heating systems with no in-line filter, do you mention that no filter was installed in the report? Do you recommend one be installed?
Oil burners here are as scares as chicken teeth but If I ever found one my answer is yes to the filter. I have a diesel truck with an extra tank which is the same as a oil burner. I have a filter on my tank pump and you should see the junk that filter catches.;-)