my burner showing code l2 tried the reset switch did not work what do I need to do

fra, May 2014

is condensate trap clear?

http://i.ebayimg.com/t/Ideal-Logic-Combi-30-Condensate-Trap-/00/s/MTYwMFgxNjAw/z/HnMAAOxyeR9TLW0O/$_35.JPG

is gas isolating valve in open position?

http://www.partscenter.co.uk/wcsstore7.00.00.749/ExtendedSitesCatalogAssetStore/images/products/AssetPush/wol-web-proof-pdp-w/std.lang.all/84/52/468452_wpdp.jpg

Q, May 2014