Log Burner Boiler pipework

[tim]

Hi All
Have two questions first is can i use 22mm pipe on heating side which is pumped and 28mm pipe on the gravity hot water and secondly how far does the copper from the boiler need to be before i can convert to plastic.
Cheers for a very informative site.

Tim

 

[Gray0689]

Yes 22mm is if on heating side and 28mm on gravity hit water but would not use plastic anywhere on a wood burner

 

[tim]

Hi5
Thanks for your advice but can you tell me why you would not use plastic pipe as my existing
heating system is about 90% plastic already.
Cheers
Tim

 

[wheeto]

... can you tell me why you would not use plastic pipe as my existing heating system is about 90% plastic already...

5. Can I connect Speedfit Pipe and Fittings directly to a central heating boiler?

No. Although most modern boilers have a high limit thermostat, residual heat can be conducted by the heat exchanger. Unless the boiler manufacturer states otherwise, a minimum of 1 metre run of pipe from the boiler casing should be copper. This recommendation includes the cold water mains supply to a combi boiler.
Speedfit Products should not be fitted to a back boiler or other uncontrolled heat source.

from John Guest Speedfit Frequently Asked Questions

Having said this, the uncontrolled heat source comment doesn't seem to appear in their latest technical advice, so maybe I'm (we're) out of date.