Shower pump - positive head

[Builder2011]

Hello and thank you for looking at this post.

A shower pump is going to be installed. The cold water to the shower pump is pressured. So is it right that the pump can be positive head even though there is no water tank (and consequently no 600 mm positive head height difference)?

Thank you for reading.

 

[bolshy]

Are you going to be pumping mains cold water??? And what about the hot water to the shower? Not much info to go on here
I foresee a disaster nonetheless..........

 

[Builder2011]

Hello there,

Thanks for your reply.

No need to foresee a disaster. (Disasters rarely happen to the well informed, and this post is about becoming well informed!)

The illustrations of the positive head pump installation show the positive head of at least 600mm from cold to allow for adequate gravity to start the pump. So the question here is that if the pump is connected to a cold water inlet from the mains, then there would already be the pressure to get the pump going without there needing to be a 600mm positive head. This is the question.

As for the hot, there is a 600 mm positive head from the top of the cylinder to the floor so that would be fine.

The pump may anyway be single impeller for the hot, with mains pressure cold direct to mixer tap.

The bathroom is a temporary for about a year.

 

[seco services]

So the question here is that if the pump is connected to a cold water inlet from the mains

Your can't put a shower pump supplied by the mains.

As for the hot, there is a 600 mm positive head from the top of the cylinder to the floor so that would be fine.

The head hight is taken from the cws that supplies the cylinder not the top of the cylinder.

 

[Builder2011]

Thank you for your reply.

The pump will be single impeller for the hot. And with the cold being mains.

Thank you again for your reply.

 

[bolshy]

Just to warn you, there's a strong possibility your shower won't work properly.

 

[Builder2011]

Hello and thank you for your reply.

The shower will be a temporary installation until a permanent bathroom is put in after about a year.

The temporary arrangement could be single impeller pump for hot, with greater than 600mm positive head, and with cold from mains (about 4 bar).

Would you be able to confirm what proposed arrangement you would suggest?

Thank you again for your comment.

 

[Newboy]

you are likely to end up with some serious pressure differential problems

try fitting a venturi shower

 

[picasso]

Start by measuring the distance between the shower head and the bottom of the cold water tank in the loft, this distance determines how much positive head you have, temporary or not don't mix mains and pumped supplies, use a twin pump and take a cold supply from the same tank that supplies the hot water cylinder,

Have a look at the salamander or Stuart and turner web sites for diagrams on how to install pumps.

 

[bolshy]

And at least then you'll have most of the components for when you install the bathroom properly in a year or so....

 

[ctp]

Dont bother trying to feed inlets to shower seperatly put in a twin impeller pump and supply hot and cold via the cws tank ,it will work properly for years.