Posting a message to the forum will remove the above advertisement
  1. Checkout our Plumbers Insurance area - heavily discounted Public Liability Insurance and Van Insurance specifically designed for plumbers.

Discuss Pump turns off on cold in the Plumbing Forum area at

  1. Mike26

    Mike26 New Member

    Hey everyone ! so first off im new here and also i dont really know much about plumbing lol so please bare with me

    We currently have a mixer shower and a salamander ct50 pump (as the pressure was bad) that we've had running fine for a few years now. Last week my sister stopped the shower (she likes to stop/start it over and over to save water) and after that it wouldnt turn back on, the pump was making this humming noise instead.

    A friend of ours came round to have a look at the pump, took it away and realised the starter motor had gone and all the gel leaked out of it, fitted a new starter motor directly from salamander, tested it at his and it worked fine.

    Now the problem is that, its been plumbed back in but the pump only starts up if its on the hot side, if we move the mixer tap on the shower to cold the pump stops and theres a little trickle of cold water instead :( if i have the mixer tap bang in the middle its not to bad but still way to hot, move it a bit more towards the cold and it will shut off the pump.

    I know barely anything so the only thing iv done is make sure there was no air lock by shutting off the pump and turning the shower on etc.

    Any ideas on what the problem could be? nothing pipe wise has changed(i think) :S
  2. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    If you turn the pump off and shower to cold does any water run out?
  3. Mike26

    Mike26 New Member

    Yeh it does, not much but yeh water does so i assume the connectors for the inlet and outlets are correct?
  4. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    If you can let it run for 5-10 mins without the pump on will clear any air lock could be the flow sensor on the pump best to change the pump if it's older than 5 years
  5. Mike26

    Mike26 New Member

    Sadly that didnt help so yeh i guess its the sensor :( thank you for your help though i really appreciate it
  6. Chalked

    Chalked Plumber GSR

    Some pumps have only one flow switch. This is normally fitted to the hot. As shower pumps are normally used for showers, not single bath taps, they would normally have some amount of hot water being pulled through. Would of being better using a negative head pump.
  7. Mike26

    Mike26 New Member

    The cold water tank is above the pump though :S and it was fine before it stopped working randomly
  8. Chalked

    Chalked Plumber GSR

    Everything is fine before it's broke:D
    If it's a twin impeller pump, most only have one flow switch.
    Could also be your shower valve is blocked on the filters on the cold inlet.
  9. plumbersm8

    plumbersm8 New Member

    I would try taking the pump out and turn it around.

    if the issue moves from cold to hot its an issue in the pump, if the issue stays on the same side then its a system issue. ( your pump has a flow switch both sides)

    hope this helps
Similar Threads - Pump turns cold Forum Date
To pump or not to pump Plumbers Arms Jun 5, 2018
Boiler cutting out after draining central heating - pump issue? Plumbing Forum May 30, 2018