Twin pumped showers, can I?

[dobbslc]

I've had a search and can't find anything about this on the web.
I need to plumb in two new showers in my house, one upstairs and one downstairs, the hot water tank is upstairs but below the height of the upstairs shower, is there a way to use only one pump to feed both showers? I think the showers will be both positive and negative head, can this work?
I hope that makes some sense!

 

[thinfourth]

I would if budget allows go for an un-vented hot water cylinder

Massive upgrade to all of the hot water

 

[dobbslc]

The cylinder needs replacing BUT we like the high pressure pumped showers and I don't think we'll get the flow off mains pressure alone.

 

[Dee J]

Ordinary shower booster pumps rely on some initial flow the activate the pump switches. If your upstairs shower is above the header tank of a vented cylinder then it won't work. But its the height of the header tank, not the cylinder that is relevant.

 

[Tigman]

a negative head pump will work when tank is lower than the shower

 

[knighty]

as long as the header tank is up above the shower it will work fine :-)

(and it must already be anyway or the upstairs hot taps etc. wouldn't work)

 

[dobbslc]

The header tank is about level with the shower head now, but I'm going to put a new bigger tank in the " top loft" so it will be about 4' higher.
Sounds like I'll be ok as long as I move the tank then

 

[dobbslc]

a negative head pump will work when tank is lower than the shower

Problem is at the moment I have both a negative and positive head shower!

 

[thinfourth]

The cylinder needs replacing BUT we like the high pressure pumped showers and I don't think we'll get the flow off mains pressure alone.

Step 1 install unvented hot water tank

Step 2 have a shower

if pressure still pap then install a whole house pump going into the house

 

[dobbslc]

I really don't want a pump running everytime I flush the bog!

 

[RonA]

I have a twin headed pump feeding my shower. The hot water cylinder is warmed by my combi boiler. The cold water tank is in the loft feeds cold water to the cylinder & the cold inlet of the twin head pump. System works brilliantly, even when my thermostatic valve packed up a while ago was able to jury rig manual valves (as the pressures on hot & cold feeds to the shower are almost identical) as a temporary solution until replacement could be purchased.

RonA

 

[thinfourth]

I really don't want a pump running everytime I flush the bog!

We are off of a well so we have a pump start each time we flush the bog

It is no biggy

HOWEVER

if you have a decent static head and pants flow then if you tweak the inlets to the cisterns down so that they fill at a low rate the pressure will never drop to the point the pump kicks in


Flow and pressure are related but are two different things

A concept that has confused many a person

 

[Wendelspanswick]

You can always bypass the auto start system of a pump with a manual switch if you have a negative head situation.
https://tapstore.com/pumps/pump-accessories/semi-automatic-negative-head-pull-switch.html

 

[8ob]

I run two negative head pumps that do the whole place, they fill the bog in seconds so thats not an issue. Two things came to light on installation , one was the feed to the hot cylinder needed to be changed to 32mm because the pumps draw so hard it would pull the vent down and cause cavitation in the pump , the other was the plumber had to add an extra tank because a five minute shower will empty a 50 gallon tank and again introduce cavitation. Both problems now sorted and no way could I go back to a mains fed system, the mains here is good enough but not good enough to run multiples of taps at the same time . The pumped system is brilliant.

Bob

 

[merryman]

a five minute shower will empty a 50 gallon tank

I always thought showers took less water than a bath. I have just luxuriated in a bath for the last hour using, at a maximum estimate, 35 gallons of bath water.

 

[dobbslc]

"if you have a decent static head and pants flow then if you tweak the inlets to the cisterns down so that they fill at a low rate the pressure will never drop to the point the pump kicks in "
Let's just say I need an err second flush quite quickly after the first sometimes......

 

[Tigman]

Problem is at the moment I have both a negative and positive head shower!

doesnt matter we put one in on first floor next to bathroom ,tank in loft on floor and shower in loft above tank ! works fine !

 

[Tigman]

The only problem with one pump and two showers is you wont get the full monty with both showers working at once !

 

[dobbslc]

doesnt matter we put one in on first floor next to bathroom ,tank in loft on floor and shower in loft above tank ! works fine !

What type of pump was it you used?

 

[Kayos]

You need universal pump, technically a negative head but uses witchcraft to not have a fit when run positive. A 3 bar will do 2 showers but tank capacity is biggest issue

Use a Surrey flange on the hot

Unvented is good but not always practical, having said that the last pump I installed cost more than an unvented