My problem is I have Baxi Riva condensing boiler not very old (1 year)
It has started to weep what I can only explain as a tacky gluey substance a little like tree sap but not as thick. There is a vent on the underside of the boiler where this substance was coming from. On closer inspection and looking at the manual, above this vent is the boiler pump and push down air valve. No sign of anything sinsister. What could this be?