Hot water secondary return pump

[WWilts]

New build in progress

 

Distance between planned kitchen sink (ground floor) & hot water cylinder (first floor) ~11m

Qus

1) Is that too short a distance for a secondary return pump to make much difference? (eg Wilo or Grundfos)

2) What diameter of water pipe would be adequate for taking hot water from cylinder to kitchen hot tap? (smaller diameter pipe easier to conceal, else have to make holes in first floor joists)

 

3) How noisy would such a pump be (Wilo & Grundfos appear to be recommended)

[JohnMo]

We are using a Lowara Ecocirc pro.  Has an integrated timer, so just needs power.

 

Runs near silent.