Log in
Article search:

Q & A

size of water pump

what size water pump would you recommendd for a 60' nb driving the usual resources and how does plumbing a second pump into the system work

Asked by: james edge  | 10.27am, Monday 29 February

WW says:

Firstly, if you are expecting to just run a shower or a sink/washbasin, (and not at the same time!) then a pump with a flow rate of around 7 litres per minutes would suffice, though one with 10 litres or more can give more "domestic-like" flow.
One thing to consider, that greater the flow rate, the more water you tend to use, so a lower flow is probably better for economy (or longer showers!).
Bear in mind that the pressure is important- ideally with a calorifier, you would want a pump running around 15 to 20psi- to much higher and it can cause issues with pressure relief valve on the calorifier (and higher pressures tend to also lead to earlier failures of the calorifier).
Twin pumps can be used in parallel, where only one is used at a time (with the other kept in reserve) and a set of isolating valves used to control. An alternative, is a pump which draws from the tank supplying the cold water side, and another drawing from the tank which just feeds the hot water side. One disadvantage of the latter, should a pump fail, say, mid shower, and it was on the cold side, it could mean just hot water is pushed to a shower. The use of twin pumps with one kept in reserse is a good compromise for inland boats, which don't tend to have complex systems.
In WW was have two more detailed articles- January 2016 "Water System Care" and in January 2013 "getting into hot water" which gives much more detailed information- and can be downloaded from this website.

Mark Langley  | 12.03PM, Monday 29 February

Readers say:

thanks that answers my query perfectly

james edge  | 12.39PM, Monday 29 February

You must log in to post an answer.