Viessman Storage Combi or Worcester System Boiler

[olyboy123]

I need to replace my old 35kw combi with either a system or combi storage (1 bath, 2 showers, 18 radiators) and wonder which system you'd go for?

I've been quoted for either a Viessman 222f Storage Combi (£6k) or a Worcester Greenstar 27i System with a Telford Tempest 250L Cylinder (£5.5K). Essentially I'm after as future proof a system as currently possible without knowing what the future of hydrogen is going to look like. A heat pump doesn't really seem an option due to the age and insulation limits of an old victorian property.

Cheers

 

[Swwils]

You need a heat loss calculation done.

 

[vulcancontinental]

The future is unlikely to be hydrogen but hydrogen blend possibly. Any hydrogen blend ready boiler can be converted to hydrogen neat boiler if that does come to fruition.

Future proof? Possibly look for a heat only hydrogen ready boiler that is hybrid ready and can be connected to and alternate between solar thermal, solar PV and a heat pump for cooling or heating with storage to suit.

 

[muggles]

The future of hydrogen is a very long way away, if it happens at all. Your new boiler will be dead and buried by the time we get any significant proportion of hydrogen being piped to homes. Personally I don't think it will happen. With the very latest experimental technology we will still need to use 4kwh of electricity to generate 1kwh of hydrogen. That means that 1kwh of hydrogen will be a minimum of 4× the price of 1kwh of electricity, and in reality it'll be substantially more due to generation, storage, and transportation costs. Pure hydrogen will always be more expensive than electricity, and so whether we like it or not heat pumps are the future.

That little hydrogen lesson out of the way, let's move on to your question. I'd always advise separate units where space allows. A good heat only or system boiler, with good modulation, capable of running a hot water priority setup on an unvented cylinder using modulating controls (OpenTherm or manufacturer-specific) is the best way to do things. Look at www.heatgeek.com/find-a-heat-geek to see if there's a knowledgeable installer near you