designer radiators don't get hot, any idea why?

[thekubs]

we bought this house and in the loft conversion has two designer radiators, see attached. virtually certain now after months of twiddling either side of the radiator that i've got it on maximum output, but they never get more than 'warm' to the touch, barely that. it's obviously the top floor and a friend of mine mentioned it maybe that the thermostat is turning off before these get a chance to be boiling hot, as it's the end of the circuit up here on the 3rd floor. Thoughts, as i'm freezing now in winter, and what i can do about it. can't get smart trv unless someone fits them professionally as the radiators aren't the screw in ones. many thanks for any help

 

[HughF]

More details required, please. Rads in the rest of the house? Gas boiler make and type? Type of wall thermostat downstairs?

[Temp]

Have you checked they aren't just full of air? They have in and out both at the bottom of the rad and are at the top of the house so if there is air in the system thats probably where it will end up.  

 

Do you have TRV on the other rads? Could be a ballance issue. Eg other rads are wide open hogging all the hot water until the stat is satisfied, then switching off the boiler before these get a look in.