JUst like ohters, I drained and refilled the SUndance 2002 Caprio and now I get a FL1 error with no heat. I checked all the jets and manual pumps that appear to be working fine. Changed my filters and unscrewed the cap as suggested in manual. Any other suggestions ? Thanks for the help in advance.

circulation pump probably airlocked - or your changed filter are not actually clean - run without filter to discount filter as a problem. loosen tubing on circ pump to allow air to escape