Gravity to pumped

[plumbdoc]

Converting old oil boiler with gravity HW to pumped system with condensing boiler.
at present there are the usual feed and return gravity pipes from the boiler. The central heating feed with a pump on the boiler splits for 2 radiators on the ground floor and the rest feeding the first floor and dropping down to the other radiators on the ground floor..
It is proposed to use the gravity feed pipe and install three way motorized valve in the airing cupboard followed by the pump with normal vents etc.
it is then proposed to feed the central heating system via the three way valve bringing another pipe downstairs and into the central heating system just before it splits. I was hoping to avoid the inconvenience of running another pipe through the house and was wondering if there are any other solutions to this problem. Any advice gratefully accepted.thanks in advance

 

[Howsie]

Not sure what problem you're describing there if I'm honest?

 

[stevetheplumber]

i rip out gravity pipework as it will be full of crud

 

[Devonplumber]

With the problems your going to have you may aswell rip out everything and fit a pressurised system and to soften the price replace the copper with the new hep pipe and fittings I know every one would prefer copper but copper does have it's price ££££££££££