How to trouble shoot your pump issues

How to trouble shoot your pump issues

There are a few reasons why a pump could be playing up. In this blog we look at the ways in which you could trouble shoot your pump issues. We will teach you how to Do It Yourself, specifically:

  1. Learn how to do the famous Burn Out Test
  2. Learn how to change the impeller of your fountain, pond or waterfall pump

Let’s get started:

First you need to check if the pump or the impeller is clogged and therefore not letting any water flow through freely.

Switch off your main power supply. Take the pump out of the water for inspection. You may need to disconnect the pipe, but usually this won’t be necessary.

Clip off or disconnect the front end filter/ strainer from the pump housing. (See arrow 1)  You may have to use a bit of force as the pump has probably been submersed for some time now. You can do this by slightly tapping the pump against an object, or using the handle of a screwdriver.  Therefore bumping the front end filter/strainer off or away from the strainer until dislodged.

You will then have access to the volute. This is the circular plate that clips or screws into the impeller housing on the pump. This is also where the water inlet for the pump is. You will turn the volute (See arrow 2) anti-clock wise until the volute comes away from the housing. This may take a bit of force again as the pump has been standing in water for a while. You can use leverage to turn the volute if need be, but be aware that too much force may break the volute instead of simply loosening it.

Once this has been done you will expose the impeller, shaft and rubber washers inside the pump impeller housing. The rubber washers will be on either end of the shaft (See arrow 3) One will be lodged in the plate that you have just removed and the other should be lodged in the bottom of the impeller housing. These are used to secure the shaft in place, to ensure smooth spinning of the impeller.

The shaft is either stainless steel or ceramic and needs to be checked that there are no wear ridges along the shaft. Please note that is your shaft is ceramic, that care is taken not to drop the shaft as they are fragile and will break.

Also be aware that on opening the housing and exposing the impeller, that the rubber washers don’t drop out into the water without you noticing them. These are essential in allowing the magnet impeller to fit smoothly and securely inside the chamber.

You can now slide the impeller out of the chamber for inspection (See arrow 4). There will be some resistance to this due to the magnetic force. Once out, hold the impeller in hand and visually inspect that any of the fins on the plastic wheel are all intact.

Hold the magnet in one hand and with your other hand rotate the plastic fins around. They should turn about 340 degrees and then stop. Reverse this action and they should stop again.

If the fins rotate freely 360 degrees around and can keep rotating without stopping at a point, then this indicates that the impellor is worn and needs to be replaced. Please make sure you reassemble the impellor into the pump carefully, and that all pieces are replaced.

If the impellor, once tested for faults, is intact then the next step will be to test that the pump still has power and has not burnt out.

By doing the same as explained above, remove the impellor from the pump. Hold the impellor in one hand and while the pump is plugged into your power supply, move the impellor close to the pump. If there is a vibration felt from the impellor magnet while moving the impellor close to the motor, then you know that the pump has not burnt out bit only needs a new impellor. If however the pump is dead and there is no vibration felt, then the pump is burnt out and depending on the warranty, can be replaced for a new unit.

You can also do a visual inspection of the cable to see that the cable has not perished or is not broken anywhere along the line. If the cable is damaged, then this can usually be fixed so long as the cable is not broken too close to the pump. There should be about 1 metre of cable that is still intact, to make joining a new cable viable. A waterproof cable joiner can be used to join the cable properly.


Keep the pump from lying directly on the floor of the pond by suspending it on a brick or a stone. This will stop the debree that is on the pond floor from being sucked directly into the pump. This can lead to the pump blocking or clogging up quicker than normal.

To shop for pump spares and impellers – click here

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