I have an ACV electric (6kW) tank in tank combi boiler that has just packed up.
No idea why, but there is water at the bottom of the cylinder (can feel this inside the insulation). It failed when I switched it on (left off several days). Before it failed I noticed the radiators were perhaps hotter than normal. It is around 4 years old.
Can anyone advise on typical failure modes of this type of system..? Does it need to be a 'certified' person to repair..? Do they require regular servicing...?
Any help appreciated..