Hot Water Recirculation and Long Pipe Runs
In a long or spread-out house the wait for hot water is a pipework problem, not a boiler problem.
In a long or spread-out house the wait for hot water is a pipework problem, not a boiler problem. A recirculation loop keeps hot water moving so it is close to the outlet when you open the tap.
The trade-off in one line
You stop wasting water down the drain and start losing a little heat from the loop instead. Insulation and timed running decide which side of that trade you land on.
Control strategies
Timers, demand buttons and thermostatic control on the return all reduce the standing loss compared with running the pump continuously.
What it needs
A dedicated return pipe, a suitable bronze or stainless pump and a non-return arrangement so the loop cannot short-circuit the draw-off.
Cut the wait for hot water
Describe how long the wait is and where the cylinder sits and we will tell you whether a loop is the right answer.
Questions we get asked
Can a combi have a recirculation loop?
Only with a combi specifically designed to accept one. Most cannot, and forcing it causes short cycling.
Does it need insulating?
Absolutely. An uninsulated loop is a radiator you did not ask for.
Will it increase legionella risk?
A properly designed loop maintaining temperature generally reduces risk; a badly controlled tepid loop increases it.