house pump set up advice

[andy1020]

hi folks,

info 1st: old house, mains fed everything, combi (bungalow , upstairs converted, no room for tanks up there even if u wanted them) and known low water pressure in the area (also made worse by a mains lead pipe from pavement to house, yes I'll replace when I get round to digging a very long trench in very steep garden...! But won't solve low pressure completely..just flow rate a bit maybe..)

So... I plan to install an upstairs en suite soon and know the additional height won't make for good pressure (probably?) and would like to improve things so a tap can be turned on in the kitchen for example without the electric shower in (existing) bathroom cutting out due to low pressure and make use of the combi to power a shower in the new ensuite upstairs which would only be possible with better mains pressure. (no plumbing upstairs just now easily added though..)

Plan so far:

Install cold tank in cellar with fast fill type valve from mains and feed entire house (cold and feed to combi for hot) from a single pump out from the tank. (At present the mains in just splits off to feed all cold taps etc and boiler in for HW near cellar anyway. Plenty space, easy fit..)

Questions

1. Does this sound an ok set up? Any better suggestions? eg: more than one pipe out of tank hot & cold twin pump instead etc??

2. What size tank? (i should measure mains flow rate right? i will when my dishwasher turns off later!! to work out how fast my tank would fill?)

3. What pressure of pump? Does a 1.5bar pump keep 1.5bar no matter what is turned on, or does it drop when a shower is used and a toilet is also flushed? so therefore you really need 2 or 3 bar etc...?)

4. Make of pump? (noise not an issue in cellar, reliability & up to the job does..) I'm pretty good with plumbing etc but no experience of choosing pumps...

5. Am I right that my combi (an ideal mini 24kw flow rate 10l/m 35C rise) will power a shower ok if I increase the mains pressure fed into it doing the above?

EDIT-- forgot to say yes i know already to have kitchen cold tap mains fed not from tank and perhaps the loo too just to decrease pump going to when not needed.... --

Any input on all or bits of above appreciated!!!

thanks folks..

 

[Dan Robinson]

I would thunk a Stuart turner universal 2.x bar pump (sorry they can fed their outputs and can't remember specific versions) would do.


The tank will need to be lifted well above the pump though.

 

[Dan Robinson]

Tank size would depend on mains flow in and the size/number of appliances it is feeding.

 

[Biggles..]

Just fit a grundfos home booster.

View media item 53953

 

[andy1020]

great thanks folks

Dan- would a 2 bar be enough for say shower to run and someone else to run a tap at same time, or washing machine to be on or something?
when you say pump below tank why can't pump be located at bottom of tank on outlet pipe? How far below are you talking? (I'm putting tank on cellar floor.. thanks

thanks Lee i'm not looking for cheapest, need it to work, but don't want to pay a lot for grundfos home booster...

 

[maltaron]

What Dan is saying is that a booster type pump has a flowvalve on the outlet pipe to switch on the pump when a tap is opened, this switch needs 1 mtr head of water to operate. I would also be wary of usind a tank for your drinking water due to the risk of bacterial infection.

 

[andy1020]

brilliant thanks!! now understand will check what the pump needs in terms of head , put tank on timber frame if needed..

Also if I wanted to run en suite combi mixer shower plus electric shower at same time what min pressure pump would you recommend? (fanily of 6 good option..!)

(Yes I know will bypass and direct mains feed kitchen cold tap for drinking... ta.)

 

[maltaron]

Sorry, can't help with size of pump, I only know of the switch because I use a similar pump for flushing toilets with rainwater from a loft tank and replaced the flowswitch with a microswitch on the ball valve.

 

[Biggles..]

View media item 53139
This would do it.lol

 

[Dan Robinson]

Minimum head for a Stuart Turner is 500mm.

One of these bad boys only needed the impeller shaft to be flooded.

Untitled

• Dan Robinson
• 8 Jan 2013
• 1

Untitled

• Dan Robinson
• 8 Jan 2013
• 1