Positive or Negative head pump.. whats the difference.. what do i need??

[ee04rrv]

Hi,

Apologies if this has been posted before.. im still unsure..

As the subject suggest, I need help in purchasing a shower pump. I already have one installed, a Salamander ESP 80 CPV, however, this is a pump, which distinguishes automatically whether the supply is positive or negative. This pump has broken down, out of warranty, and a new one needed! im looking to buy a stuart turner monsoon, as i have heard these are very good in quality.. however, im unsure whether i need a positive one or a negative one.

Here are the details..

2 floor house.. cold water storage tank in the kind of in the attic.. the current pump (in a utility closet - based on the 2nd floor), is located just beneath it (about 1 metre below), with 1 bathroom, to the side of it... and a shower unit on the first floor. The pump is for cold water flow.

Question is.. is this positive or negative flow? im not a plumber, just an average joe.. trying to get the damn shower unit working again... lol! please try and provide non-technical answers.. as they will just confuse me... and prob lead to more questions.. lol!

Thank you in advance...

 

[PlumbBobBob]

your pump is positive head, you would need negative head if your pump was above the tank in the loft.

 

[mikegas]

You will need a positive pump

 

[Blackcatgas]

Shower head higher than the tank = Negative head, shower head lower than the tank= positive head.

 

[Gray0689]

Monsoon pump needs cold tank 1 metre above cylinder with dedicated feeds
You will need positive head pump
And great pumps far better than salamander

 

[ee04rrv]

Cheers for the replies all.. almost easy enough for me to understand..
positive it is!!

 

[WHPES]

My shower head is above the height of the tank so to make the shower run I have to drop the head in the bath to make enough head to trigger the pump (a second hand one from a customer who I installed a combi boulder for). No it's not that I'm too much of a tightarse to fork out for a negative head pump - I just still haven't got round (or saved up for) to fitting that Heatstore cylinder and solar panel I have planned!