250 litre unvented cylinder with 13 radiators - which boiler

[McCarron]

would the best bet be a heat only boiler with all my valves etc external of boiler on the unvented cylinder?

what size would you recommend as a rough idea for the boiler

House will be 5 bed with 2 main bathrooms and jack & jill bathroom (3 powerful showers would in total)

so basically im after the best boiler and cylinder duo you would recommend? LPG boiler

35kw do the job?

thanks

 

[Gasman77]

24kw max

 

[McCarron]

anyone fitted a viessmann to an unvented system? 5 years warranty?

 

[Kev F]

Quite a few yes, you'll need a min 20kw just for the cylinder coil

 

[McCarron]

whats the biggest heat only boiler? or would i have to look at a system boiler with the 250 litre cylinder?

 

[DP]

Why not fit a combi and let boiler supply HW to kitchen sink?

 

[commercialman]

Quite a few yes, you'll need a min 20kw just for the cylinder coil

Then you get the keyboard jockeys saying a 10kw boiler would be adequate.

 

[McCarron]

who is right who is wrong!!! lol

 

[commercialman]

who is right who is wrong!!! lol

Lets put it this way , with a large family using hot water @ peak times recovery time should be around 30 minutes , this would require roughly 35kw heat load (250 litre) , food for thought.

 

[McCarron]

at the minute there is one person

whast the best heat only boiler £3k will be enough for 250l cylinder and boiler big enough with all the pipework etc?

 

[DP]

Lets put it this way , with a large family using hot water @ peak times recovery time should be around 30 minutes , this would require roughly 35kw heat load (250 litre) , food for thought.

If coil in the cylinder is rated at 25kw, CH is off, does the OP really need 35kw boiler?

OP, also think solar panels. Install suitable UV cylinder ti then look to have solar panels connected later.

 

[mickyg]

surey if your an engineer you know how to size boilers?

 

[bengasman]

so basically im after the best boiler and cylinder duo you would recommend? LPG boiler

Far more important is your choice of installer, let him make the choice of boiler.

35kw do the job?

1 kW for every metre of radiator panel you have ( plus planned ones ) will do the job. Add a bit if there is any chance at all of future extensions.
With the arrival of independent timers, the need to include boiler capacity in the boiler calculation became obsolete, unless you have an unusually high dhw demand during the day e.g. B&B or 6 sprogs that all do mud-wrestling.

 

[McCarron]

Thanks for all your help ive never done a house this size so was looking for a bit of feedback so its much appreciated. viessmann system boiler with viessman vitocell unvented looks the dogs.

cheers

 

[Gasman77]

Put loads of that combo in, if you do it install it as a 4 pipe system, which has hw priority and you can control the heating and hot water wirelessley. Also you can add weather compensation for about 40 quid, and most of your system will be covered by a 5 year warranty