DIY Doctor UK DIY Forums

Unfortunately, a new rad has connections that are wider apart, further out from the wall and higher than the old rad. Too much for the existing pipe runs. I'm trying to plan a way forward. For background we have a mains fed System Boiler and an unvented, indirect cylinder.

There are 2 drain points in the feeds to the cylinder, which is on the ground floor. The first is at the bottom of the pipe to the "Primary Flow". I'm assuming this is the coil to heat the water and is part of the CH system. The second is at the bottom of the pipe to the "Inlet". I'm assuming this is the cold feed for water that will go to all the hot taps, etc., after being heated in the cylinder.

My guess is I need to turn off the mains and drain from the "Primary Flow" until the water level is below the pipes to the rad being replaced? Do I just turn the water back on to refill the system? I'm thinking I should flush the system and service the Magnaclean at the same time?

Hi willsie01
You need to depressurise the primary system and drain it down to below the radiator you are replacing. Refilling and pressurising is done through the fill loop probably located on the boiler. No need to flush the system your magnaclean should do this for you. You may have issues with air in the system especially if the boiler is above the radiator. Don't forget to top up the inhibitor.
Regards S