FAQ - Losing Pressure On Your Drain Cleaner or Water Blaster?


Are you losing pressure on your drain cleaner or water blaster and can't figure out why? This is an issue we hear about all the time at Kerrick and we understand just how frustrating it can be. New Zealanders are practical people and by working your way through this handy checklist we've created for you, there’s a good chance you’ll be able to figure out what’s going on with your jetting equipment.


Low Pressure?


Low water supply. A lower flow of water means the pump will not get to the required pressure and it will “cavitate” causing damage and ultimately complete failure. It’s extremely important to maintain a constant and adequate supply of water to the pump.

  • Check water tank is full / tap is turned on.
  • Check for any leaks or obstructions to the flow of water into the pump.
  • Check manual to ensure inlet port and line OD are correct and aren’t restricting the water flow.
  • Flush hoses/lines in gravity fed systems.

Nozzle is worn or you’re using the wrong size. If your nozzle is worn or too big, the hole the water passes through is larger than it should be and therefore provides less resistance. Less resistance equals less pressure.

  • Replace with a correctly sized new nozzle. If you’re not sure which nozzle size is the best fit for your equipment come chat to the team at Kerrick and they’ll do the calculations and set you up with the right equipment.

Faulty Regulator. A regulator is a pressure control valve that sets and maintains system pressure. A worn or “stuck” piston can cause excess bypass flow and low system pressure. 

  • Strip the regulator and check for wear/restricted movement in the piston valve assembly. Depending on damage either clean and repair or replace the internal piston.

Faulty Unloader. Check to see if the unloader is by-passing water back to the tank or pump head properly (unloaders help to regulate pressure).

  • Check condition of the seal at ball and seat.
  • Check for any obvious damage.

Worn or dirty valves and seals. Damaged valves and seals result in lower flow and pressure overall.

  • Check and replace as needed.

Pump not turning. If the pump doesn't turn, there will be no flow.

  • Check for key in shaft and replace as needed.
  • Check for belt slippage.
  • Check electric motor or engine for faults.

Belt slippage. Belt slippage results in the pump running at a lower RPM, which in turn affects pump output. Less flow equals less resistance, which equals less pressure.

  • Check belt drive assembly and tighten or replace belts as needed.

The details above are a general guideline, individual client needs may vary.  Kerrick has trained servicemen on board who specialise in water blastinghigh pressure jetting and drain and sewer equipment. If you need further assistance in identifying and resolving a problem with your drain cleaner or just need a general service give us a call on 0800 253 774 from anywhere in New Zealand,  contact us via the website or drop into your local branch.

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