Boiler size estimate

[Bogart]

Considering replacing old Camray with a new unit. Have approximately 25kw of rads installed plus say 3kw for the hot water tank giving 28kw. Now the boiler is some 15 metres from the house feeding in 35mm copper insulated pipe under a lawn. In the very near future I will change this for a properly insulated twin pipe setup. Is my estimate of a 32kw or 36kw boiler enough or should I aim higher say a 36?46kw ?

 

[ShaunCorbs]

How many rads also copper cylinder?

 

[Bogart]

20 rads and copper cylinder. Have worked out rad load using the normal delta 50

 

[ShaunCorbs]

I would go with a 36kw could always range rate it down

But I would do the insulated pipe first least you know your coupling onto good pipe and not swish cheese

 

[noelm]

I would go with a 36kw could always range rate it down

But I would do the insulated pipe first least you know your coupling onto good pipe and not swish cheese

Many years ago I did something similar moving the Boiler out to a detached garage to gain kitchen space. The distance was about 40 Ft and buried about 2- 2.5 Ft. I insulated it well but the heat loss was massive. The Boiler nearly ran continuously in Deep winter. Ended up replacing the Boiler with a Wall hung back in the kitchen.
I wouldn't do it without the new specialist insulated pipe. With a heat loss of less than 1%.

 

[Bogart]

Only been here a year and so much to do so the replacement insulated pipe will wait till next year. I was surprised last winter at how little it showed re heat loss. I thought after every frost I would see 2 green lines across the grass not so.