Hi guys,
The 35 year-old Glow-Worm conventional boiler that heats my fairly large 4-bed house is situated about 4m away from the main body of the house, at the far end of a single-storey extension.
The flow and return pipes that exit and enter the boiler are 28mm (boiler has 28mm connections) and this size pipe continues at least as far as the utility room is long (ie. 4m), before disappearing into the house and, after the HW cylinder, eventually reduces to 15mm at the radiators. (There may be 22mm sections inbetween but I haven't taken the floor up yet)
The current system is costly to run and inefficient, so the idea is to replace the boiler and radiators and reduce the overall system volume (the circuit currently also runs under the floor downstairs in 22mm pipe and we're going to be removing this and connecting downstairs radiators from above)
Now - the new condensing combi will have 22mm flow and return. The plan is to take that 22mm into the house and come off that in 10mm microbore to the radiators via manifolds.
My question is - is this thinking 'sound' ?
I realise that you can't make specific comments without seeing the 'site' so it's general observations/rules of thumb/thoughts that I'm after here.
ie. Is 28mm used in domestic installations of this size these days ? Would there ever be a case for going straight to 28mm from a 22mm connection on a modern boiler and if so, what would be the reason for doing this - length of pipe runs/property size etc ?
Many thanks in advance for your thoughts.
The 35 year-old Glow-Worm conventional boiler that heats my fairly large 4-bed house is situated about 4m away from the main body of the house, at the far end of a single-storey extension.
The flow and return pipes that exit and enter the boiler are 28mm (boiler has 28mm connections) and this size pipe continues at least as far as the utility room is long (ie. 4m), before disappearing into the house and, after the HW cylinder, eventually reduces to 15mm at the radiators. (There may be 22mm sections inbetween but I haven't taken the floor up yet)
The current system is costly to run and inefficient, so the idea is to replace the boiler and radiators and reduce the overall system volume (the circuit currently also runs under the floor downstairs in 22mm pipe and we're going to be removing this and connecting downstairs radiators from above)
Now - the new condensing combi will have 22mm flow and return. The plan is to take that 22mm into the house and come off that in 10mm microbore to the radiators via manifolds.
My question is - is this thinking 'sound' ?
I realise that you can't make specific comments without seeing the 'site' so it's general observations/rules of thumb/thoughts that I'm after here.
ie. Is 28mm used in domestic installations of this size these days ? Would there ever be a case for going straight to 28mm from a 22mm connection on a modern boiler and if so, what would be the reason for doing this - length of pipe runs/property size etc ?
Many thanks in advance for your thoughts.