I live in a 42 year-old, 3 storey semi with separate CH and instantaneous DHW systems. I installed the CH system myself some 40 years ago using a Crane Cavalier 45000 BTU cast iron boiler and vented system. The DHW system has seen 3 multipoint appliances installed - the original Ascot, followed by a Main Severn and now the current one, a Main Medway.
All units have given excellent service. We don't have a problem with using just one hot water outlet at a time and shower pressure is good. Both appliances are installed in the basement and space is not a problem.
The Crane boiler now needs replacing (new burner jets needed). I wondered about replacing both units with a Combi but am put off by the numerous horror stories of experiences with this type of appliance.
I am now thinking of keeping separate systems and looking to choose from Worcester-Bosch (recommended by a local Corgi friend) or Vaillant products although I have been told of a corrosion problem with cast aluminium heat exchangers.
Could you let me have your views on my situation and which boiler (combi or regular) manufacturer would you recommend between the two above?
If a Main Medway gives you sufficient water then a Combi boiler should be good enough for you. Buying a boiler with a greater flow rate will provide a better hot water supply.
"I wondered about replacing both units with a Combi but am put off by the numerous horror stories of experiences with this type of appliance" no different to any other appliance, back boiler, system boiler, combi boilers all breakdown at some point. Buy a decent boiler, have it fitted correctly with inhibitors and you shouldn't have many problems.
The majority of problems you get with boilers are poor installation techniques, not flushing to remove flux and copper filings, not adding inhibitors, not adding llimescale inhibitor to hot water sections, fitting new boiler to old radiators and pipework and again - not flushing etc etc...... Parts become worn and full of crap the boiler fails, saving a few quid at installation may cost huindreds in the future. get the job done properly.