Fitting a pump just for the shower

I'm looking into fitting a pump for the shower. I want to know if it is possible since the pump will go just before the mixer valves.

The pipes from the storage tanks are link to the shower and the rest of the house, hence I want to connect the pump to the pipes that go to the shower.

Thanks

Yes - it's possible, but depends on a few factors that you haven't brought to light yet, viz:

1. Type of water supplies - tank or mains fed;
2. Pipework length and gauge;
3. Head - distance between base of cistern and shower outlet (spray thing);
4. Type of shower (any body jets, etc.?).

1. Both supplies are tanks

2. Pipes will be less than 3m from the pump, Im not sure what you mean by gauge. From the hot and cold tanks pipes go to the rest of the house and 2 pipes goes to the shower from hot and cold tanks respectively.

3. I know my shower is negative head, distance is very small though 10cm, almost level.

4. Normal mixer valve shower


This is what I'm worried about, from the techflow website:

http://www.techflow.co.uk/qtinstall.htm

It says:

Both HOT and COLD supplies must be dedicated / exclusive to the pump (i.e. not shared with other services).

mayhem86 said:

1. Both supplies are tanks

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Okey dokey - so you can install a fairly normal twin impeller pump then.

2. Pipes will be less than 3m from the pump, Im not sure what you mean by gauge.

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That's a good distance - not too long. By gauge I mean diameter, e.g. 15mm or 22mm. The pump manufacturer will no doubt recommend 22mm.

From the hot and cold tanks pipes go to the rest of the house and 2 pipes goes to the shower from hot and cold tanks respectively.

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Hm. I'm not sure at what point these two feeds diverge, but see below.

3. I know my shower is negative head, distance is very small though 10cm, almost level.

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In which case you'll be needing a negative head pump. For example the Stuart Turner Monsoon 2.0 bar 'negative'.

4. Normal mixer valve shower

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OK.

This is what I'm worried about, from the techflow website:

http://www.techflow.co.uk/qtinstall.htm

It says:

Both HOT and COLD supplies must be dedicated / exclusive to the pump (i.e. not shared with other services).

Click to expand...

Nothing to worry about, particularly. What this means is:

A. The cold must be taken from an independent outlet from the storage cistern. This is to prevent the drawing off of cold water to other taps affecting the shower temperature.

B. The hot must be taken from an independent outlet from the cylinder. This is where the Essex flange comes in.

Note that you need to ensure the cold storage cistern doesn't empty during the course of showering. This is achieved by taking into account the following:

a. Shower pump flow rate;
b. Cold mains flow rate into the cistern;
c. Cold storage capacity.

Hopefully you're already getting the drift, but you subtract the mains flow in from the pumped flow out, and work out how long that deficit will take to empty the cistern. If that's less than the time you take to shower (somewhere between 5 and 10 minutes) then the cistern is large enough. Most shower pump manufacturers recommend a 50 gallon cistern, but they err on the safe side to prevent the pump being starved and its life foreshortened.

Ref A) abd B) - yes that's perfectly correct, but it's surprising how often people do it all wrong and still get away with it. I think sometimes it's worth a try at the easiest place to install, and see how it works!

Quite so - 'twas only last week that I installed two Monsoon N2S (single) pumps in two flats, each on the outlet from the cylinder about 300mm below the vent tee, and in each case CSS was a 4 gallon jobbie in the airing cupboard shock.

The mains flow is nice, so the setup seems to work fine for the tenants and has saved the landlord a small amount for Essex / new CSS / labour / fittings etc.

Thanks alot for the help. Now I am definitley sure what to do. Great forum.