22mm existing pipe or change to 15mm central heating

[TerryEddy]

Hello All,
New member here,
Im not a plumber by trade only a weekend Diy when i get the chance

Long story short, In the lounge and dining room we have some radiators they are double rads

2 x 11823 btu in the lounge
1 x 11823 btu in the dining room

the 22mm pipes enters the lounge via a 4.2m run to the first rad then another 6m run to the next rad then another 10m to the dining room rad

i believe 22mm is the correct size taking into account the length and btu size of the rads

boiler is a woscester bosch 30cdi combi boiler using a flow and return method for the ch

the concrete screed has crumbled and requires repairing so im taking this chance to replace the piping

i believe copper would be a good choice as its lasted 40 years to date

 

[ianmcd]

Yes copper is best, but if within a screed it must bewrapped to protect it from corrossion and any joints must be soldered, you actually get pre-coated copper a little more expensive but worth it for what you are doing

 

[TerryEddy]

Yes copper is best, but if within a screed it must bewrapped to protect it from corrossion and any joints must be soldered, you actually get pre-coated copper a little more expensive but worth it for what you are doing

ah thats a new one on me, brilliant ill look for that now, is 22mm the correct size as above, thanks

 

[ianmcd]

ah thats a new one on me, brilliant ill look for that now, is 22mm the correct size as above, thanks

I would keep the sizes as is , it works , you dont want to change the size and install the screed then find out down the line that you have a circulation problem

 

[ianmcd]

ah thats a new one on me, brilliant ill look for that now, is 22mm the correct size as above, thanks

you can buy it in 25m coils so no joints to worry about, as said expensive but you will never be doing it again so do it right