boiler size

Are you getting rid of your 24i then?

Thanks for that. Can't imagine there will be any advance on 335

Now that's a point. I wonder if the mains pressure is up to that...

Well spotted :-) No, this one isn't for me. I'm advising them to keep their open vent system and just replace the ancient floor standing boiler, but combis are tempting when you're short of space.

I would advise converting the system to a sealed system and putting in a one of Vaillant's 600 series boilers.

Look at a the Broag Avantapluc 39C combi. It is well priced and has integral weather compensation control. It is £917 inc VAT, that is very well priced for a 40kW boiler.

The tanks in the loft and the pipework are all fairly new, it's really only the boiler that needs replacing. Would it be worth the extra work to change to a sealed system?

The reason why I would advise to change to a sealed system is because many regular band A boilers don't cope very well with "system imperfections".

If they were to decide converting the loft to a bedroom with a sealed system you can have a radiator there.

Ok Dave, thanks for the advice

Some boiler makers insist on them. It's usually quite easy to convert, though.

If you have reliable mains pressure water, its the best solution.

ATM I'm not sure it is reliable. If it's a question of upgrading the pipework from the mains, it might be worth doing, but that will depend on when Thames Water decide to put a stopcock/meter in the road. At the moment it isn't an option. Time maybe to ask the neighbours what sort of system they have.

Doesn't a sealed system just refer to the primary? That's only what I was referring to. The higher pressure makes filling easier - less airlocks.