Keep it, very good boiler cast iron heat exchanger could easily last 30 yrs . Im sure your service engineer will tell you the same ! parts may become obsolete in years to come though
From a selling on point yes a more efficient combi would be more appealing to buyers ! £2000 ish and a baxi combi with a 7 - 10 yr warranty would be a good option, if you are goin to rent the property stick with the bbu
looks like youve replaced everything you can, can you check if the boiler burner is alight when the controlls are off or not ? sometimes gas valves can pass gas when not calling for heat !
Hi, if the wingnut will not tighten up anymore to seal the leak i would take the cistern off and put some silicone sealant on the bolts before putting them through cistern, that will cure your problem
Hi. it sounds like the diaphram washer could be split in the water section to me ! a baxi service kit from plumb centre/ hrp should sort it out about £14