Wrong boiler for house?

[rrman76]

Evening all

We have just had a new boiler fitted in our house, the Worcester Bosch Greenstar 30si.
It was fitted in March but as it is only just getting cold and it is the first time we have had our heating on, it is the first time it has really been used in anger. I have noticed though that our attic radiator and towel rail are not getting hot (only the very bottom) even after 30 minutes. Our house comprises:
3 ground floor radiators
3 first floor radiators + towel rail
1 attic radiator + towel rail

After checking the Worcester Bosch website, it says that the 30si is suitable for "apartments and small to medium sized 1 bathroom properties."
And it recommends the 42cdi for our property type.
So 2 questions:
1 - do you agree that the boiler we have is not sufficient for the size of the house (could it be something else that stops the attic heating up?)
2 - if it is not sufficient, what are our options? Can we make the installer fit the correct one free of charge after we followed his advice on the current one?

All advice much appreciated!

 

[landyandy]

Sounds like air in the offending radiators.

They might need bleeding.

 

[ALEC1]

or balancing...

your house isn't that big...with that many radiators I would be thinking 15kws for a system boiler...combis obviously are rated to hot water...

 

[ianmcd]

That boiler is more than adequate for your house size you need to bleed the attic radiators and then top up the water system pressure at the boiler

 

[rrman76]

Thanks for the quick replies people.
I will get installer back in to bleed the attic.

 

[ianmcd]

if its been fitted since march your installer will quite rightfully charge you to bleed the rads just do it your self its not hard

 

[rrman76]

good to note - thanks for that. looks like DIY!

 

[ianmcd]

Its very easy to do shouldnt take any more than 10 mins start to finish