Is this a good new system?

I am building a new extension and so my old Ideal Classic LXFF boiler, about 8 years old, has to go. (Although building inspector said I could make a case for keeping it, so there is obviously some discretion at least in Wandsworth BC).

I reckon I might as well get rid of it now and get a condensing boiler, as financially it is even weighted: the energy savings v keeping an old boiler going. I want to keep going with an open vent sealed system as I cannot use the roof space where the cold water tank is and I want a hot water cylinder as an airing cupboard, among other useful reasons.)

The house is 4 beds, one bath and one shower.

I am ready to go for a Vaillant Ecotec Plus 428 (£852 inc VAT), plus a Valiant Instor 155 litre hot water cylinder (£572 inc VAT).

I reckon this is a good, conservative choice, with everything Valiant. The hot water cylinder seems to have an expansion vessel. Would this be duplicating the expansion vessel I have in the loft?

In which case, am I wasting money?

I want to keep going with an open vent sealed system

Click to expand...

you mean sealed heating open vent hot water

you want to replace the cylinder with an unvented one

the ex vessel on the cylinder has nothing to do with the one you already have

kevplumb said:

I want to keep going with an open vent sealed system

Click to expand...

you mean sealed heating open vent hot water

you want to replace the cylinder with an unvented one

the ex vessel on the cylinder has nothing to do with the one you already have

Click to expand...

Sorry about if it was garbled. The old, non-condencing boiler has a red expansion vessel in the roof and a cold water tank.

So, basiccally, its a sound choice as a replacement?