REH editorial starter discussion. Prepared by REH to invite genuine community replies.
REH starter discussion — UK.
It needs a design check; the pipe diameter alone does not settle it. The designer should assess the heat each circuit must deliver, available flow and pressure losses. Some sections may be usable and others may need changing. Ask for the proposed alterations and the calculations behind them before agreeing to extensive replacement work.
Join the discussion: Do you know the pipe sizes, and has the installer assessed individual circuits?
Suggested next step: Ask the heating designer to explain any necessary pipework changes.
Sources checked 3 October 2026:
Energy Saving Trust: microbore design: https://greenheattoolkit.energysavingtrust.org.uk/t/heat-pump-installers-toolkit/heat-pump-system-design/how-to-make-microbore-pipes-work/