Microbore system help

[Tcmichael]

Hi there,

I've got a closed loop microbore system that I need to change 2/3 radiators.

The rads have single fill valves. 8mm microbore. There are two rads on the system that have been converted to the normal 2 valves and I want to do the same with these two new ones.

I think this is the process I need to follow..... am I missing anything?

1. Turn off the boiler and close the valves on the rads I'm changing
2. As I've got no drain, going to close the valve on the lowest point rad, attach a hose and drain
3. Remove the rads and valves
4. Rework the microbore piping, adding new pipe work to either end of the new rads.
5. Buy 8mm radiator valves so no seperate compression is needed
6 fit the new rads and valves (might get a draining value on the lowest rad)
7. Refill the system

Have I missed anything? Do I need an inhibitor?

I'm a beginner at heating but fairly ok at plumbing and a quick learn!

Thanks!

 

[denso13]

On point 1, leave the valves open so the radiator and pipework drain down. Point 7, refill and bleed. And yes, inhibitor is a good idea.

 

[sooey]

Don't close the valves on the rads you're changing or they won't drain.

 

[Tcmichael]

Thanks both makes sense

When I'm running pipe in order to have separate flow and return valves, can I use plastic piping? How do I connect these to the existing flow?

 

[sooey]

You can though it doesn't look very nice if it's on show. You can connect with a pushfit straight connector if the old pipe is clean and in good shape, otherwise use a compression fitting.

 

[Tcmichael]

You can though it doesn't look very nice if it's on show. You can connect with a pushfit straight connector if the old pipe is clean and in good shape, otherwise use a compression fitting.

Cheers

If I just connect new copper piping will I need to solder to the existing pipe to connect it?

 

[sooey]

Soldered looks best, though again you could use pushfit or compression.

 

[Tcmichael]

Ok, I think I'm getting this.

So I can easily fit a return valve onto the return flow pipe.

For the feed ill need to fit a elbow compression and run the pipe underneath the back of the radiator to the feed valve? I guess it'll just be a case of screwing and tape for the connection...... no need to solder?