I have been looking at the layout of my central heating. Because my house is old it has solid ground floor and solid internal walls. Boiler is on ground floor but supply and return pipes go into ceiling void and there is a pump. These pipes run left to right through the middle of the house, and then there are radiator loops of the supply and back on the return, radiators for ground floor drop down on inverted loops. The main supply/return pipes are bigger than the pipes connecting to the radiators. At the right end of the house the supply pipes narrows, connects to radiator which then connects to return where the pipe then widens again.
Is it good or a bad that the main supply/return is wider than the radiator pipes?
I read a paragraph in my Collins Complete Diy Manual book that mentions outdated one-pipe systems, not clear if my system is that or a regular open-vented system