3 radiators not working (cast iron and new rads fitted)

[StuAJ]

Hi

I have recently purchased an old house (built in the 60's) and it has 3 of the old-style cast-iron rads downstairs and new style radiators upstairs.

All of the downstairs radiators are working well (3 cast iron and 2 new stlye) and 2 of the new style radiators are working upstairs (although both these are small radiators) the other 3 large bedroom rads are not working at all.

I have bled the radiators and clean water is coming out and I have also turned off all the hot radiators to try and allow hot water to the rads that are not working but to no avail. The inlet pipe just below the cold rad feels warm but the heat is not coming through the rad!

A new ideal icos combi boiler was fitted just before we purchased the house.

Could it be anything to do with the mix of cast iron and new style rads?

Thanks in anticipation

 

[kevplumb]

what sort of valves are fitted to the rads

 

[StuAJ]

standard valves on the new style raditors (lockshield?) and the cast iron rads just have a single valve with a round handle.

Thanks for the quick response.

 

[kevplumb]

close BOTH valves on one of the rads thats not working

open the bleed and let the pressure out

close bleed

open a valve and listen for water coming into the rad

repeat for other end

keep an eye on the boiler pressure

 

[gas4you]

Is it an Icos heat only or Isar combi boiler. There is not an Icos combi

If it is an Icos is it a system boiler or do you have a header tank still? (pipes will come off top of boiler)