Converting an old one-pipe system

[JackK]

I have a similar setup and woud be keen to know what boiler to choose - I have mexico 2 and also have a one pipe system using 2 inch pipework in my house

Wanted to convert the system to sealed system but worried about streeing the pipework so did look at using a central heating dealer but decided against it

Im almost ready to buy a Intergas HRE OV heat only boler as a straight swap - Any ideas from the forum - Replacing and rip up not possible sadly

 

[Exedon]

Something we do fairly regularly (we do oil boilers but principal same ) some systems have 3in or even 4in pipes.
Fit a suitably sized plate to plate heat exchanger to fully separate new boiler from old system.