draing down a microbore ch system

[slowbuild]

I want to alter pipework- 8mm- to replace old with new radiator upstairs . System has manifolds upstairs & down - under floors. Do I drain system as normal i.e. open drain cock at lowest point etc .Can I part drain ?. CH is about 20 yrs old. has both 8 & 10 mm pipework .

Also when hot water only is on , upstairs radiators get warm/hot.

 

[kevplumb]

drain as normal
dont disturb the manifolds
had 1 fall to bits on a old system recently

 

[slowbuild]

Thanks for that . Can I part drain ? i.e. just drain enough water out until the pipe I want to work on is empty ?.

 

[kevplumb]

yes

 

[slowbuild]

Kevplumb your a star , what do you think about the rads getting warm when only the water is on. I have the ch system with a big & small tank in the loft , the cylinder is the type with the coil inside from the ch .

 

[kevplumb]

do you have zone valves or gravity hot water

 

[slowbuild]

Kevplumb I,m sure its gravity - there are no valves anywhere on the system .

 

[kevplumb]

could be a long vertical leg in the pipework is pushing it round hard to say without seeing the system