DIY Doctor UK DIY Forums

When my local firm installed a combi boiler he mixed up the in and out pipes, such that the TRVs are now where the water exits the radiator The system is microbore with 2 manifolds & TRVs I helped install in 1979. The system is more noisy than before but he says this is because of the higher pressure. Is he right? Also, I am changing some radiators: which way round for the inlets now?

before the 1990's TRV's had to be fitted with the arrow on them on the flow,now it doesn't matter,either way round and there's no shuddering noise,easiest way is to replace the trv's if they have an arrow on them