Central Heating Pipes

knittingnanny1102

My central heating pipes seem very complicated and wondered if anyone could offer any comment on the set up. I always thought the flow and return pipes should run in one single loop right round the property.

I have from the boiler a flow and return which at ceiling height split left and right. The right side runs into the lounge where it circuits 3 lounge radiators and returns back with the left heading into the other side of the property and circuits the dining room and hallway.

Is it ok to have the lounge set up like this or should it be part of the same loop. I just don't understand how water can go in 2 directions at the same time and heat up correctly

sheenas

it’s normal to have a number of loops. This makes sure that all rads get hot water. I agree the pipe work does seem complicated, but it does work.

Section62

https://forums.moneysavingexpert.com/discussion/6677980/central-heating-pipes

I just don't understand how water can go in 2 directions at the same time and heat up correctly

Each radiator usually has two valves, one of which (known as a 'lockshield') is set to regulate the flow through the radiator. The whole heating system should be 'balanced' when installed or modified, a process which involves the adjustment of all the lockshield valves to give optimum flow through all radiators.

So in principle it doesn't matter if there is one, two or more 'loops' - except if a too small bore pipe is used in part of the circuit which means the system can't be balanced properly. Splitting the system into two circuits means it is more likely 15mm pipe will be sufficient, rather than having to have longer runs of 22mm pipe.

The only rule that should be followed is to ensure all the central heating circuit return pipes are 'commoned' (i.e. joined together) before the hot water cylinder return (if there is one) comes in.

There were some historical systems - 'gravity' or 'single pipe' - where it was more important to get the layout right, but with modern pumped systems the proper regulation of the system using lockshield valves means there is more flexibility with circuit design.

molerat

My system is like a tree starting off in 28mm from the boiler splitting into 22mm branches for up and downstairs then as short as possible 15mm pipes go to each radiator. When I had an extension another 22mm branch was teed off from the downstairs branch running all the way into the extension with short 15mm feeds off to the new radiators. The feed and return don't actually join in a loop, only through the 15mm radiator pipes.