Barn Conversion , combi boilers?

[mjparks12]

Can you help guys? , we are renovating an old barn and want to put in a combi boiler as the wife wants instant hot water. We will end up with 4 bedrooms spread over a single storey part and a 2 storey part. Single storey with kitchen/diner utility/downstairs shower room, and 1 bedroom, all with radiators and under floor heating. 2 storey part has main bathroom, 2 bedrooms 1 with ensuite, again all with radiators. Other main bedroom will have rads and ensuite room.
im after a combi boiler that will run heating/hot water , also underfloor heating in 3 large downstairs rooms, plus all the rads.
Any ideas guys? i have been looking at a Worcester Bosch Greenstar 42cdi , sounds good and seem to be for larger properties , but i need plenty of advice.
Please help if you can.
Thanks.
Mark.

 

[ServiceNumpty]

If you are looking to run more than one hot water draw off, consider un unvented instead of the combi. By the time you price up the 42cdi install with an unvented there may be a couple of hundred quid difference. Plus all the components are external to the boiler, easier to diagnose and repair.

 

[obiplumbkinobi]

It think you may be strecthing a combi a bit far for your requirements.
I count 2 ensuites, main bathroom and downstairs shower room plus kitchen and utility from your post. Also how far is it from the proposed postion of the boiler to the various bath/shower rooms?

 

[Alfredo]

Depending on how far from the hot tap your combi is, the hot water is rarely if ever instant, so the good lady might be disappointed in the 30-40 second delay getting HW at the tap. You would get just as 'instant' hot water from a cylinder.

As others have said, a combi will only work as long as only one..possibly two hot taps are being used. They cannot generate the throughput if there is more demand. A combi looks like a bad plan to me.

You do have to find a home for the cylinder, but provided you have reasonable mains pressure and supply I'd say the BEST solution involves an unvented cylinder. It also gives you some redundancy if the boiler breaks down as you will have an immersion back up, so never be without hot water. You discount this at your peril, and I speak from experience.

You can also extend a cylinder system to include solar thermal when funds allow. This is not an option with a combi.

Alfredo

 

[John67]

Don't spoil your conversion with a combi, are you having a wood burning stove? if so i would recommend getting one with a boiler and linking it up with a gas boiler to a thermal store, then you would have plenty of hot water and you wouldn't be tied to one energy source, It also gives you the option of solar in the future.

The system would cost more but well worth it.

 

[bengasman]

How many hot water points are likely to be used simultaneously at any one time?