Question Author
Wow,thanks for all the replies!
I had checked pump speed previously,which is situated inside boiler. It is set at 3,which is max setting.
I will try method of tezestwing next when i have a few hours to spare without kids. I have done exactly what you said except for removing trvs. What is the advantage of this,is it to make sure they are operating correctly,or is is possible they are not connected correctly ie 5 setting maybe 3???or is this not possible
I have checked all rads for air,nothing in any of them.
I have only rads upstairs,underfloor downstairs