i have baxi plat 28 which has just developed a leak on a joint , had it installed about 4 months ago, now i cant tighten this joint up as it seems to be a soildered joint. Now would this be a case of either calling baxi and getting them to fix (it has a 5 yr warranty) or do i call the plumber bk to fix it as i am not sure wheather its a pre manufactured part of the boiler or not, any help appreciated. I have enclosed the offending part!