Lubi Team Successfully Resolves Auto Cut-Off Issue in Pressure Booster Pump by Removing External Deposits from Pressure Hole


Client: Residential Society on the outskirts of Udaipur, Rajasthan.

Complain: Auto Cut-off not working in Pressure Booster Pump


Nameplate Of Product
pressure booster pump
Lubi Pressure Booster Pump (MH series)




  • A residential building had installed our Lubi inline pressure booster pump (MH series) to provide adequate/ equal water supply on all floors.
  • One day we received a complaint from them stating that the auto cut off was not working. 



  1. Customers can call on our toll-free number to raise a complaint, following which they will receive a text message with reference to the complaint and the contact details of our service engineer.
  2. Our Engineer usually calls up to fix an appointment as per the electricity schedule of the area - as there are frequent power disruptions in some places.


  • Our service engineer reached the site as per the pre-scheduled appointment.



  • On reaching the site, our service technician started his inspections to verify the complaint and find the cause of the problem.


pressure booster pump
Installed Pressure Booster Pump


  • Delivery (Outlet) Valve: To begin with, our technician switched on the pump and “closed” the delivery (outlet) valve. Under normal circumstances, the pump should have automatically stopped, but this time it did not, which was a clear indication that the auto cut-off was not working properly.
  • Suction (Inlet) Line: Another reason for this problem could be a leak in the suction (inlet) pipeline. Our technician checked it but did not find any leakage.
  • Pressure Gauge: If there is any leakage in the suction or delivery line, the pressure changes. Hence, the pressure gauge can be a good indicator of possible leakages. However, in this case, the reading was as per recommended levels, negating the possibility of any leakage.
  • Non-Return Valve (NRV): Our technician then checked the NRV by removing it. He checked its spring tension and poured water manually. The NRV passed all tests, confirming that there was no problem with it.
  • Pressure Control Switch: After checking all the above parts, our technician then moved on to check the Pressure Switch.
  • The main function of the pressure switch is to automatically turn the booster pump on and off at pre-defined pressure levels.


Caution: Always switch off the main power supply before inspecting the pressure switch.


  • Our technician removed the Pressure Switch from the pump connector and checked its electrical contact terminals.


As there did not seem to be any problem with the terminals, our technician inspected the “pressure hole” (Refer Diaphragm on image) on the lower side of the switch and found external deposits in it.


External Deposits In Pressure hole



  • After cleaning the “Pressure hole” properly, the pressure control switch was refitted (using a Teflon tape to avoid any leakage) to test the pump and cut-off function again.


Cleaned Pressure hole


  • Our technician switched on the power supply and closed the delivery (outlet) valve and immediately the pump stopped, indicating that the cut-off was now working properly.
  • In order to re-confirm the same, the technician reopened the delivery (outlet) valve and opened the taps and faucets. As soon as he did that, the pump started working and stopped after the taps and faucets were closed.



  1. The auto cut off function is managed by the Pressure Control Switch.
  2. The pressure can be increased or decreased by turning/ adjusting the nut on the pressure switch. If the pressure is increased more than the capability of the pump, the pump will not cut (turn) off automatically.
  3. If the auto cut-off is not working properly, it is better to switch off the power supply (and open the bypass valve) or it might damage the pump.
  4. The Pressure Control Switch may not work due to the following reasons:


  • Leakage issues - Leakage in the NRV or Suction / Delivery (inlet/outlet) valves, can all lead to failure of auto cut-off. Any leakage in the house like taps, faucets, toilets can also result in abnormal functioning of the cut-off function.
  • External Deposits - Always ensure that only “clean and soft” water enters the booster pump or else the debris from the water may get deposited in the switch or valves, thereby impacting the performance of the pressure control switch.
  • Electrical contact points - The cut-off function can be seriously impacted if the electrical contact points are loose or damaged.
  • Bypass Valve - The Bypass line must be opened only when the pressure pump is not working. If it is left open, it will cause a drop in the pressure and impact cut-off function



The following measures can ensure that your booster pump lasts longer with little or no downtime.


  1. Ensure only clean and soft water enters the pressure pump.
  2. Provide continuous power supply of 180-230 Volts (Single Phase). Improper power supply can significantly impact the performance of the pump.
  3. The size of the delivery and suction pipes can have a considerable impact on the pressure. Always install the pipes as recommended by the pump manufacturer.
  4. Avoid leakages. Any kind of leakage can impact the pressure.
  5. It is always beneficial to install a “Float Switch” to monitor the water levels and prevent dry runs.
  6. Always check the movement of fan (behind the pump) before switching on the pump. It should not be jammed or obstructed in any manner.
  7. The Non-Return Valve is a very critical component to ensure the smooth functioning of the pressure pump. Therefore, it is very essential to install the NRV carefully and at the right location.
  8. Ensure adequate levels of pre-charged air in the Pressure tank. The pressure gauge will always indicate the levels.
  9. Do not change the factory setting of the Pressure Switch without consulting the service technician. In scenarios where pressure needs to be increased or decreased, it is always advisable to ask the dealer or service technician to make the changes.


Final Words:

  • Always follow the guidelines provided by the dealer while buying or repairing the pump. You may also refer our user manual or call our toll-free number for any assistance.