Electrical shower fault finding and repair: Triton T90 XR Repair: Fix Low Pressure & Internal Pump Motor Faults

Working on electric showers is dangerous. You are dealing with a high-voltage appliance (240V) and water.
ISOLATE POWER: Always turn off the electricity at the main consumer unit (fuse box) and pull the isolation cord before removing the shower cover.
VERIFY DEAD: Use a voltage tester to ensure no power is reaching the unit.
LEGALS: In the UK, major electrical work in bathrooms is "Part P" regulated. If you are not a competent person or are unsure of these tests, stop and consult a Part P qualified electrician.
DISCLAIMER: You follow these guides at your own risk. This site and its authors are not liable for any injury, loss, or damage caused by your repairs.

Lots of faults on this one.

The "Grunting" Sound: If the shower makes a loud noise but has low pressure, the pump's Carbon Brushes are likely worn out or the impeller is blocked with grit.
The "Total Silence" Fault: If the shower turns on but the motor doesn't spin, you need to check the Pump Capacitor or the PCB relay.
The Indirect Water Link: Remember, the T90 XR is designed for Gravity-Fed (Tank) systems. If you have air-locks in your tank, this pump will burn out. Always "prime" the pump before full power testing.
Motor Brushes: Unlike standard Tritons, the T90 XR uses a brushed motor. If these brushes are less than 5mm long, the shower will behave intermittently.

0:00 – Introduction: Overview of the T90 XR "Pumped" system vs standard electric showers.
1:45 – Safe Teardown: Accessing the motor assembly and the PCB.
3:20 – Testing the Motor: Using a multimeter to check the winding resistance.
5:10 – Carbon Brush Inspection: How to remove the motor brushes to check for wear.
7:45 – Clearing Air Locks: The correct way to bleed the pump after a repair to prevent a "dry run" failure.

See video of this process below , thanks for looking.