secondary return location

[redbarnman]

Have to put in a secondary return pump to deal with a new en-suite 16m from 250L pressurised cylinder (digital shower and basin to feed). Does 22mm out and 15mm return with a Grundfos UP15-14B on the 15mm return seem OK. Any thoughts on whether pump should be located in the en-suite (easier to wire into a PIR / time switch) or near the cylinder with consequent longer wiring job.

 

[ShaunCorbs]

15mm is fine but the key is it must be well lagged / insulated

And pump located at the cylinder for me

 

[Chalked]

Near the cylinder for me. Don't forget a lightly sprung non return . Or a swing check valve

 

[townfanjon]

G3 ??????????

 

[ShaunCorbs]

G3 ??????????

Don't need to be as it's not messing with anything critical to the safety

 

[townfanjon]

Don't need to be as it's not messing with anything critical to the safety

Erm !!!! Lol

 

[AWheating]

Unless the tprv is removed to fit the return. Always need a G3 plumber imo

 

[redbarnman]

Will be done by a G3 plumber but what I have found over the years is that every plumber has an opinion and that having G3 does not mean that you then become an expert on all aspects of plumbing. Hence the value of these forums - ultimately though you have to make the best decision based on a number of inputs. No one has mentioned putting a flow restrictor on the return pump - you only need to pull enough hot water round the system with the pump to cope with the heat loss of the pipes leading to the furthest draw off. If the pipes are well insulated that could be as little as 1 litre per minute. The comment on using a swing check valve on the pump output to prevent reverse flow is good as the pumps don't create much head to force open a sprung pegler type NRV