It got a BIASI RIVA compact combi boiler. How do i got about drainig the central heating system? Does it just involve just closing the C.H Flow and return pipe and draining the radiators? or do i have to open the drain cock in boiler too?
Also i am planning of installing TRVs do i need to change anything in boiler for installing them?
Also i am planning of installing TRVs do i need to change anything in boiler for installing them?