cold bedrooms??

[renton]

hi all,
i have a problem with the two larger bedrooms in our house not staying warm at night.

we live in an end terrace ex cuoncil house .

the house has had cavity wall insulation and double insulation in the loft.

the two bedrooms that are cold are on the external wall of the property.

its worse in the back bedroom which is the boys bedroom.

my house has central heating with rads in all rooms with trvs.

boiler is a potterton envoy.

all rads get hot apart from the two big ones down stairs which are colder at the bottom , despite balancing.

the two bedroom rads are quite small for the size of the room in my opinion.

the rooms are roughly 9 foot by 15 foot.

the rads are 50cm by 60cm single units.

are these adequate for the room or not??

it feels colder around the window in the back room but i cant feel a draft coming in anywhere(double glazed btw)

any ideas on what i can do please as it can be nice for the boys??

 

[swbjackson]

Go to http://www.stelrad.com/UK/stars.html and you can download a rad sizing program. You can then work out what size rads you should have to provide the necessary heat.

Cold at the bottom of the downstairs rads may indicate a build up of sludge.

Mike