Shower Pump

[pixey]

Hi, I have a mains fed electric shower in an upstairs shower room that often won't work due to low pressure. It is a problem in the area that I live in.
My question is: I have a Stuart Turner Monsoon 1.5 bar twin pump sitting in the garage unused. Can I take a seperate outlet off my cold water tank, tee the two inlets, tee the two outlets, (as the shower only has a cold water feed) and then connect it up to the electric shower?
Or.. can I just use one inlet / outlet, leaving the other inlet / outlet un-connected?
I know I would be better off with a single inlet / outlet pump, but as I have this one at hand....

Any advice appreciated.

P

 

[Goldberg]

An intriguing idea, but I don't see why it can't be made to work.

I recommend running 22mm pipework all the way from cistern to pump inlets. And I'd fit a 22mm full bore single check valve on each outlet before joining them together.

Don't leave one impeller dry - it will seize up before you finish your first shower.

When using the shower, be prepared to have to start it on the minimum temperature (i.e. maximum flow) position each time if that's what it needs to get the pump's flow switches to operate. And don't neglect priming the pump on first use, i.e. run the shower before you supply power to the pump for the first time.

 

[Agile]

You are not normally permited to pump the mains supply.

The pump seals are not safe at the maximum mains pressure which could be suplied.

What exactly is your mains incoming presssure?

The water cos are expected to provide about 0.6 -1.0 Bar and an open tap flowe rate of about 6 li/min.

Thats not very good of course.

You would be better with a storage cistern and a shower pumpo!

Tony

 

[Goldberg]

You are not normally permited to pump the mains supply.

That's completely irrelevant - he isn't planning to do that.

You would be better with a storage cistern and a shower pumpo!

You would be better with a reading of the first posto.

 

[kevplumb]

My question is: I have a Stuart Turner Monsoon 1.5 bar twin pump sitting in the garage unused. Can I take a seperate outlet off my cold water tank,

yes seems a bit of overkill tho

 

[doitall]

Run the pipes in whatever the pump connection sizes are, it will work much better.

What pump do you have, is it a positive or negative head type.

 

[Goldberg]

Run the pipes in whatever the pump connection sizes are, it will work much better.

I can't think of any reason for not using 22mm on the inlet side, and 15mm on the outlet side, and I've never seen any MIs that conflict with that.

 

[doitall]

Most 1.5bar pumps I've seen have 15mm connections.

 

[Goldberg]

Most 1.5bar pumps I've seen have 15mm connections.

I might even agree with you, but that's no basis for restricting the flow into the pump, when doing so might lead to starvation and/or cavitation.

 

[bathstyle]

It depends on the run between Cold cistern/Cylinder to the pump itself.

I must admit though, I always tend to do it it 22mm partially, then reduce down. It makes the installation future proof and just feels right.

 

[doitall]

Most 1.5bar pumps I've seen have 15mm connections.

I might even agree with you, but that's no basis for restricting the flow into the pump, when doing so might lead to starvation and/or cavitation.

In a low pressure installation, you get a higher flow rate through a smaller pipe, which activates the flowswitch better.

 

[Goldberg]

In a low pressure installation, you get a higher flow rate through a smaller pipe

You can't increase the flow rate by restricting the flow. What you're thinking of is an increase in water velocity, for a given flow rate, if you reduce the pipe gauge. This is explained by Bernoulli's principle.

...which activates the flowswitch better.

No.

The flow switch is inside the pump inlet, so isn't affected by the water velocity in the supply pipework.

 

[bathstyle]

The bottom line is that 22mm pipe is better. Doitall is of the age where he cannot be wrong about any subject on any forum so I wouldn't even bother.

The guy has been using Forums for 15 years and is yet to post a topic asking for help

errrrr....love you really Doitall

 

[pixey]

Thanks for all your replies. The pump is 22mm in and out and I don't know if it is positive or negative, although I would assume negative.
Is there any way I could fit the pump in the loft although the cold water tank is only raised about 6 inches above the joists?

pixey

 

[bathstyle]

No, can't go up there i'm afraid