How many BTUs on our boiler?

[silverous]

Hi,

We need to upgrade a radiator in our bathroom, we think we know how many BTUs we need it to be but do we need to check that we aren't going to overload our boiler somehow?

How do we figure out how much load the boiler can take and what the current load is?

Thanks

Paul

 

[petit_pablo]

What boiler is it?

It will give KW / BTUs in the instruction manual and on data badge

 

[JPC]

you can get a catalogue and measure the rads and look up the btu or wattage. your boiler will have a data badge...or in the name..ie baxi80 have 80.000 btu
as a rule of thumb putting in an extra rad/larger rad would not be problem

 

[silverous]

Thanks. It's a Worcester Bosch Greenstar 24Ri

This is a scan of the manual if you can help me make sense of it:

http://img177.imageshack.us/img177/2838/boilerbj4.jpg

(might have to click in IE to zoom). I've highlighted our model (yellow).

Does that mean max of 24-25 KW? What is that in BTU? And how do I relate that to all the radiators (of which I don't know the BTU) in the house?

We're looking at replacing a rad that we think is about 1800-2000 BTU with one that is around the 3000-3500 mark.

Thanks

Paul

 

[silverous]

I couldn't see a "data badge" anywhere though, what does one of them look like? Not that it matters now if the above is enough info.

 

[mikeyd]

24 Kw = 82000 BTU

 

[GasMan1965]

How many rads you got at the mo?

I fitted an 18ri not long ago in a fairly big house with 17 rads and she is running just fine !!

 

[DP]

It is not the number of rads that is important but the rad output. If you could have a 24Kwatt rad, you would only be able to fit one, or 24 1kw rads or 96 250w rads.

Asking how many rads can be fitted to a boiler is like asking how long is a piece of string.

 

[GasMan1965]

It is not the number of rads that is important but the rad output. If you could have a 24Kwatt rad, you would only be able to fit one, or 24 1kw rads or 96 250w rads.

Asking how many rads can be fitted to a boiler is like asking how long is a piece of string.

True but it gives an idea and it would have to be a mahoooooosive room for a 24kw rad

Ok as above measure all rads to get output and total up,, dont forget the cylinder

Happy now

 

[JohnD]

if you have an ordinary-sized house, 24kW will be plenty.

If you have a room stat and thermostatic radiator valves, and reasonable insulation, you will probably never use that much.

 

[silverous]

Thanks chaps, this is really helpful.

It's a reasonably large 3 double bed house. So we've got rads in Lounge, Kitchen, Utility, Hall, Cloakroom, Study, Bedroom x 3, Landing and en-suite. So I make that 11 rads unless I'm mis-counting.

So is it safe to say 82000 BTU divided by 11 Rads means each could be up to approx 7400 BTU before we'd have an issue ?!

 

[GasMan1965]

You really wont have a problem mate

 

[silverous]

Thanks. So if I order the rad do I need to order a thermostatic valve for it as well or will whoever fits it sort that? It is a chrome towel radaiator, dual fuel.

 

[GasMan1965]

You may as well supply the valves as well and yes fit a TRV !!

 

[JohnD]

24kW boiler and 11 rads means they could be an average of over 2kW each which should be plenty. With TRVs mine probably use about 1kW each on average. Even on the coldest days the boiler doesn't run continually flat out (though it did before I had the cavities filled, and after running a bath you noticed the house get cold for 20 mins).

I have 9 rads and an old 22kW boiler

A 2kW rad is a finned double 600×1200mm but it depends how cold the room is, and how hot the rad.

I don't do BTUs

I am just a householder.