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Is my CH/HW fully pumped? Is it two-pipe?

phloaw Member Posts: 9
I'm having problems understanding the exact configuration of the CH/HW piping in my house.
In particular, I have to understand where and how to place piping for additional radiators at the upper floor.

My configuration is the classical one: loft cistern, indirect cylinder on the upper floor, gas boiler on the ground floor. (my house is a two-floor terraced house, quite standard I'd say)
This is the official installation diagram taken from the boiler's installation guide (I think "heat exchanger" can be identified with "boiler" for our purposes):

Contrasting that, this is how the boiler plumbing actually looks, from the left side (the smaller pipe on the bottom is irrelevant since it just passes through the boiler):

and from the right-hand side:

Given the number of pipes (4) attached to the boiler, and given the first figure, it looks like a non fully-pumped system.
However, the location and number of valves: one for HW (top right last picture) and one for CH (bottom right of last picture) suggests a fully-pumped one.

Any clue of what the actual situation is? Any test I could take myself to ascertain that?
And what about the radiators configuration? Is there a way to know if it's a two-pipe or one-pipe system?
As I mentioned, my main reason to know that is the perspective addition of radiators to the existing CH.



  • hot_rod
    hot_rod Member Posts: 19,925
    Classic UK open to atmosphere system?

    Looks like #1 is a heat exchange to separate the "open" boiler piping from some of the the radiators?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Jamie Hall
    Jamie Hall Member Posts: 21,542
    hot_rod said:

    Classic UK open to atmosphere system?

    Looks like #1 is a heat exchange to separate the "open" boiler piping from some of the the radiators?

    Or possibly from the domestic hot water. Is the domestic water -- cold and hot -- fed from the cistern? Or even from a different cistern?

    Unless you can actually find a pump, at least the part involving the heat exchanger and the cistern is most likely gravity flow; that's the reason for the relationship between the pipe length and the head -- elevation difference -- required in there.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • phloaw
    phloaw Member Posts: 9
    Thank you all, I lost access to this forum and I see your replies only now. To answer my questions: I have a fully pumped open vented system, S plan.