I'm using Oerlikon Supercito 7018 but my welders complain saying the welding characteristics have changed, is there another electrode that I can use that meet our boiler code requirements, F4 and A1?
The purpose of filler metal specifications is that qualified products are interchangeable for code work. Thus AWS E7018-1, iron powder, hydrogen-controlled, coated welding electrodes, complete with release certification meet the code classification for F4, A1.
Equivalent low hydrogen welding rods that you could try would be Eurotrod BN18 or Esab OK 48.00.
Make sure that a full COA is available with chemistry, hydrogen potential and mechanical properties, released to AWS A 5.1 E7018-1 and meets boiler code requirements for F4 & A1 to ensure the procedure requirements are met.
Welding Tips & Techniques
You may want to let the welders get used to the feel of the replacement electrodes, so maybe order a small quantity to start with. This question often arises with welders for many reasons; but mainly due to a change in quality resulting in welders no longer feeling comfortable with a previous product.