Combination Boiler or unvented system with a tank??

[Steve Williams]

Hi
I am re-furbishing a five bed, three storey Edwardian terraced house with four bathrooms. Would a "combi" instant type boiler be right for the job or should I have a boiler with a hot water storage tank? I may want a solar hot water facility when the work is done or at a later date. The ground floor will have UFH. I have room for a tank roughly in between the kitchen and bathrooms whilst the boiler will be on the top floor.
Many thanks
Steve

 

[Simon F]

you are right to question this point Steve.
A combi however large would not cope with that much demand, if in use at the same time.

depending on the layout, possibly advantages to have more than 1 boiler? more than 1 hot water cylinder?
unvented? thermal store? ground source heat?

best to get someone in to recommend possibilities.

 

[Steve Williams]

Thanks Simon. I probably won't need two tanks or boilers as the layout of the house means the bathrooms/kitchen are all quite close. I think the Combi option is out, although thats what is being replaced- albeit two showers were electric and clearly the hot water produced is inadequate. Second heating engineer around today!

 

[Ray Stafford]

Definitely not a combi. Assuming incoming mains pressure and flow rate are adequate, it sounds like an ideal job for a large unvented cylinder (300 litres) with a solar coil. You don't have to use the solar coil to start with - it can either be blanked off, or temporarily connect both coils to the primary circuit for faster reheat times. If you go this latter route, a little forethought in isolating valves will enable you to add in solar later with very little disruption.

 

[Centralheatking]

Ray has said it all - he is spot on end of !

Definitely not a combi. Assuming incoming mains pressure and flow rate are adequate, it sounds like an ideal job for a large unvented cylinder (300 litres) with a solar coil. You don't have to use the solar coil to start with - it can either be blanked off, or temporarily connect both coils to the primary circuit for faster reheat times. If you go this latter route, a little forethought in isolating valves will enable you to add in solar later with very little disruption.