Posting a message to the forum will remove the above advertisement
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. Checkout our Plumbers Insurance area - heavily discounted Public Liability Insurance and Van Insurance specifically designed for plumbers.

Discuss Help - guidance on right shower pump piping setup in the Bathrooms, Showers and Wetrooms area at

  1. duckie

    duckie New Member

    I have got a new shower bathroom installed and as part of that have a Smart Tap "smart" shower. (SmarTap - A New Shower Experience)

    To ensure there was enough pressure of min 1 bar I was recommended to install a shower pump by my (earlier and now fired) plumber.

    It appears that the GrundfosSTR2 1.5 Positive Twin pump has not been installed correctly and/or the piping configuration is incorrect for the shower pump.

    The setup is - shower pump, smart controller and cold water tank in loft on same level, hot water storage tank on floor below in airing cupboard, shower on the same floor.

    The pump connections - cold water from the tank next to it (same level), hot water is piped up from the bathroom and into the pump inlets. The respective pump outlets are then fed into the smart controller unit. The smart controller unit then has 3 outlets which are piped back down into bathroom to the shower, handheld and bath filler.

    When I try to activate the smart controller it tries to start but does not receive any water. The app shows water pressure to be 0.1bar when it requires a min 1 bar.

    I believe my best options would be -

    * Move the existing pump down to the airing cupboard and next to the hot water tank & connect it to pump

    * Cold water will have a pipe coming down to the airing cupboard and connect to the pump.

    * From the pump both hot & cold water outlets will be piped back up to the loft and connected to the smart controllers respective inlets.

    Alternatively, if I keep existing pipework I would need a new Negative Head pump (Which I want to avoid as they are expensive plus I would waste the money on my existing pump)

    Appreciate any tips and guidance.

    Note: this is not a self-install but I appear to have not been lucky in selection of the plumber who installed original.

  2. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    Well that’s an abortion
    • Agree Agree x 2
  3. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    How’s the top of the cylinder looking
  4. Craig Watson

    Craig Watson Plumber GSR Top Contributor!!

    The pump wants moving for sure, but depending on setup it might not be that pump that wants moving. The best location for the pump is next to the cylinder at it's base.

    You also say the cold storage tank is located to the right of that setup. What is the height of this tank, directly on the joists or raised up on a platform?

    Why is the hot water inlet coming from the bathroom? It should be coming direct from the hot water tank.
  5. YorkshireDave

    YorkshireDave Plumber Top Contributor!!

    As mentioned, it's time to start again.

    Best you sit and exlain with diagrams & pictures what your end point is. We then stand a chance of helping properly.
  6. Svenedin

    Svenedin Member

    You can't have a positive head pump at the same level as the cold storage tank. It will not get the required gravity flow to start the pump. It should be on the floor near your hot water cylinder. The pump will need a dedicated cold feed from the tank and a dedicated feed from the cylinder in 22mm via a flange. The pump installation looks a total mess with a bizarre switchback from the cold outlet going to the shower. I can see the outlets in plastic pipe nicely clipped in but why are the connections to the pump with flexible hoses? I don't know anything about the SmarTap other than there was another thread recently and I read the instructions. 1 bar is minimum but I think the recommended was between 2 and 5 bar.
  7. Rob876

    Rob876 Member

    Need to think about the water coming from tanks, the force of which will be from gravity which can only do so much and needs correct placement to ensure sufficient pressure to pump.
  8. shyguy2005

    shyguy2005 GSR

    As said before a picture of hot outlet on top of cylinder would be good.

    More than likely plumber has just tee’d off vent.
  9. duckie

    duckie New Member

    Thanks for all the responses and I will post more details and info. Going to go on site and turn the boiler on + more details on the piping as I still have not got my head around it completely. Until then here are some photos of the boiler tank + the pipes under the bath.


  10. Svenedin

    Svenedin Member

    I’m not actually sure this is going to work with a positive head pump even if you move it to be on the floor next to the cylinder. It’s going to depend on the drop between your cold water tank and the actual shower rose. If that is only a small distance there won’t be enough flow to trigger the pump to start. A negative head pump (or universal) would work because that doesn't rely on a flow switch to start the pump, it senses the pressure drop when an outlet is opened. I can't see any sign of a dedicated hot feed to the pump from the cylinder.
    Last edited: May 27, 2019
  11. duckie

    duckie New Member

  12. Craig Watson

    Craig Watson Plumber GSR Top Contributor!!

    Your hot water connection is definitely wrong. You either need it taking off the cylinder direct with a Surry flange or tee'd off about 200mm below the tee piece on the hot draw off.

    Svenedin's reply regarding the distance between the tank base and shower rose is slightly wrong. You do need a minimum head which is 600mm but this head is between the base of the tank and the highest point of the shower, in your case this would be the shower valve in the loft, so if you don't have a 600mm differnece between the two then you will need a universal pump.
  13. duckie

    duckie New Member

    Thanks all - so if I read (and understand) correctly the best option in my situation would be to replace existing with a Universal (Negative) pump in the same location. This would remove the need to do any more piping work and more or less guaranteed to work.
    (I did a quick search and the Stuart Turners pumps although very pricy seems to be the ones to get - a 3 bar one could potentially be sufficient in case I add another bathroom in the near future. Prices are high so any tips on best location to purchase appreciated.
  14. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    The pipework will still need correcting as at the moment it is not clear if the existing pump has its own hot feed from the cylinder or or cold feed from the tank. Both issues will need addressing as well as the stressing on the pump inlet and outlets. I believe manufactures give 15-20° flexibility to meet pipework. Yours are bent completely over
    • Like Like x 1
  15. Craig Watson

    Craig Watson Plumber GSR Top Contributor!!

    Personally I'd move it. You can have pumps in the loft but best practice is to install it at the same level as the base of the cylinder. If you want to keep the pump in the loft then technically you should have an independent Essex flange fitted into the side of your cylinder and pipe it up with an anti gravity loop. I personally have never done this (because I don't fit pumps in lofts) nor have I seen it but it will void your warranty if not correctly installed.
Similar Threads - Help guidance right Forum Date
Help! Vaillant boiler not working after changing out a radiator Central Heating Forum Today at 3:38 AM
Quick polyplumb question, anybody help? Plumbing Forum Yesterday at 4:52 PM