Worcester Greenstar Heatslave 12-18 Rad Capacity

[PeteJ]

Hello

I have a Worcester Greenstar Heatslave Internal 12-18 installed and it's currently running 7 rads (6 are around 60-90 x 60cm, plus one tiny rad in toilet). I'm looking to add 6 more (five 60-90cm plus another tiny rad). I've done the BTU calculations - current rads around 23k BTU, looking to increase to around 40k BTU.

Would this be too much for the boiler to run?

Cheers
Pete

 

[ShaunCorbs]

Is your boiler a combi or do you have a cylinder? (Can't remember what it is)

Your increase is going to be around 12kw

So yes it should work just

 

[PeteJ]

I have a cylinder as well. Thanks for the reply.

 

[ShaunCorbs]

It will work but try and stagger your heating and hot water times so there both not on at the same time

 

[doitmyself]

Your increase is going to be around 12kw

So yes it should work just

I think you have misread the OP's question. He isn't increasing the rads by 40k BTU but to 40k BTU. So the boiler will be easily able to handle the load.

 

[ShaunCorbs]

I think you have misread the OP's question. He isn't increasing the rads by 40k BTU but to 40k BTU. So the boiler will be easily able to handle the load.

Works out 12kw and I know he isn't that 40k btu is the total rad heat load 5-10kw for a cylinder = 17-22kw

 

[PeteJ]

Thanks both. At the moment, the boiler heats two rads whenever it heats the cylinder - no idea why! A bummer on hot days.

 

[ShaunCorbs]

Thanks both. At the moment, the boiler heats two rads whenever it heats the cylinder - no idea why! A bummer on hot days.

Them two rads are on the cylinder circuit normally only one rad but quite common in the good old days

 

[Stigster]

Thanks both. At the moment, the boiler heats two rads whenever it heats the cylinder - no idea why! A bummer on hot days.

Before the days of Automatic bypass (or any bypass at all) it was common practice to leave one radiator uncontrolled, usually the bathroom rad or rail, to act as a bypass and "heat leak". Two rads piped like this would be more unusual though. Maybe someone teed in to the heat leak/bypass radiator pipework to connect that second rad? I'd turn off those if you don't need them in the summer. You can just turn the TRV to the frost setting or zero if it has it.

If there is no TRV you should have a wheel head and a lockshield valve on the rads. It's possible you could have two lockshields on the rad in which case you'll need a screwdriver to take the valve cap off and an adjustable spanner or a pair of grips to turn it off.

edit - ShaunCorbs beat me to it as I was typing but said it much more concisely than I can ever manage!

 

[PeteJ]

Ah OK, thanks. The system was installed in 2010, so not too long ago - perhaps it was installed by an old boy.

 

[SimonG]

Heatslave is a combi boiler. Sounds like a camray or danesmoor.

Get your oil engineer to re rate the boiler to the higher output. Will be fine.

 

[PeteJ]

Apologies, it is a Camray - just found the installation guide.