Troubleshooting
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      2. Installation support
      3. Troubleshooting

      Troubleshooting

      A quick reference table for troubleshooting issues when installing and servicing a Mixergy cylinder.

      In addition to the content below, you can also access a number of training and troubleshooting videos. See Mixergy Training for Installers.

      1. General troubleshooting
      2. Mixergy Solar X Issues
      3. PV Switch Issues
      4. Heat Pump Kit Issues

      1. General troublshooting

      Water Quality Issues

      The water is milky or cloudy

      • Possible Cause: Oxygenated Water
      • Solution: Water from any pressurized system will release oxygen bubbles when flowing. The bubbles will settle out.

      No Hot Water Flow

      Cold Main Off

      • Possible Cause: Cold main is turned off.
      • Solution: Check and open the stopcock.

      Blocked Strainer in Inlet Control Group

      • Possible Cause: Strainer is blocked.
      • Solution: Isolate the water supply, strip, and clean the strainer.

      Incorrectly Fitted Inlet Control Group

      • Possible Cause: Inlet control group may be installed incorrectly.
      • Solution: Check and refit if required.

      Water Escaping from Case Unit

      Pipework Compression Fitting Not Sealing

      • Possible Cause: Compression fitting is leaking.
      • Solution: Check and remake the joint.

      Leaking Cylinder

      • Possible Cause: Cylinder leak.
      • Solution: Isolate the supply and contact Mixergy.

      Cold Water at Hot Taps

      Heat Source Not Working

      • Possible Cause: Boiler, heat pump, or solar issue.
      • Solution: Check the heat source; consult the manufacturer’s instructions.

      Immersion Heater Not Switched On / Cutout Triggered

      • Possible Cause: Heater is off or cutout has tripped.
      • Solution: Check and reset.

      Motorized Valve Fault

      • Possible Cause: Motorized valve issue.
      • Solution: Check plumbing and wiring to the motorized valve.

      Circulating Pump Fault

      • Possible Cause: Faulty pump.
      • Solution: Check the pump and consult the manufacturer’s instructions.

      Dual Stat Cut-Out Operated

      • Possible Cause: Safety cut-out triggered.
      • Solution: Reset and investigate the cause.

      Hot or Warm Water from Cold Tap

      Heat Transfer in Pipework

      • Possible Cause: Pipe picking up heat from nearby hot pipes.
      • Solution: Insulate or re-route the pipe.

      Low Water Pressure

      Service Valve Not Fully Open

      • Possible Cause: Valve is partially closed.
      • Solution: Ensure the service valve is fully open.

      Partially Blocked Strainer

      • Possible Cause: Blocked pressure reducing valve strainer.
      • Solution: Check and clean the strainer.

      Restricted Delivery Pipework

      • Possible Cause: Old or damaged pipework.
      • Solution: Replace affected pipes.

      Low Mains Pressure

      • Possible Cause: Insufficient water supply pressure.
      • Solution: Check the incoming mains pressure or consult the local water supplier.

      Water Not Hot Enough

      Boiler Not Providing Enough Heat

      • Possible Cause: Boiler thermostat set too low.
      • Solution: Ensure the boiler thermostat is set above 65°C.

      Cylinder Thermostat Incorrectly Set

      • Possible Cause: Thermostat is set too low.
      • Solution: Adjust the thermostat to 55°C–65°C.

      Status LED Codes

      See 'Troubleshooting with the Gauge' as part of the Mixergy Trainign with Roy Fulger series for a walkthrough. 

      Flashing Green Light

      • Status: System is OK.

      Solid Green / Red Light

      • Status: System updating.
      • Solution: Do not turn off the power.

      Very Slow Flashing Red (Every 2 Seconds)

      • Issue: Temperature sensor issue.
      • Solution: Check the temperature sensor.

      Slow Flashing Red (Once a Second)

      • Issue: No gauge detected.
      • Solution: Check that the gauge is plugged in correctly.

      Fast Flashing Red (Twice a Second)

      • Issue: Energy measurement issue.
      • Solution: Contact Mixergy technical support.

      Very Fast Flashing Red (Five Times a Second)

      • Issue: Main processor issue.
      • Solution: Contact Mixergy technical support.

      Hot Water Discharges from Temperature & Pressure Relief Valve

      Overheating Issue

      • Possible Cause: Thermal controls have failed.
      • Solution:
        • Switch off power to the boiler, heat pump, and immersion heater.
        • Leave the water supply on until discharge stops.
        • Isolate water supply and replace faulty components if necessary.

      Water Discharges from Expansion Relief Valve

      Continuous Discharge

      • Possible Cause: Faulty pressure reducing valve.
      • Solution: Check outlet pressure from the inlet control (should be 3 bar).
      • Possible Cause: Dirty or damaged expansion relief valve seat.
      • Solution: Remove cartridge, check seat, clean, and replace if necessary.

      Intermittent Discharge

      • Possible Cause: Expansion vessel charge reduced or bladder perished.
      • Solution:
        • Check pressure in the expansion vessel.
        • Recharge to 3 bar if necessary.
        • If the bladder has perished, replace the vessel.

      Back-Pressurization Issue

      • Possible Cause: Cylinder pressure equal to incoming mains pressure.
      • Solution: Install a balanced cold supply.

      Noise During Hot Water Draw-Off

      Expansion Vessel Over-Pressurized

      • Possible Cause: Incorrect pressure.
      • Solution: Check pressure and adjust to 3 bar.

      2. Mixergy Solar X Issues

      Cylinder Always Switching Immersion On to Full Power

      • Possible Cause: Current clamp installed incorrectly.
      • Solution: Ensure the current clamp is attached around the neutral cable on the incoming mains supply, with the arrow pointing toward the incoming supply main fuse.

      Rapidly Flashing Red Light on Cylinder Controller

      • Possible Cause: Cylinder unable to detect the current reader.
      • Solution: Check wiring between the cylinder controller, diverter, and current clamp.

      3. PV Switch Issues

      3rd Party Solar Diverter Not Working

      • Possible Cause: Solar diverter is unable to supply heat to the cylinder.
      • Solution:
        • Check that the solar diverter is set up correctly according to the manufacturer’s instructions.
        • Adjust the immersion heater thermostat to maximum.
        • Ensure the cylinder is not entirely full of hot water (100% charged). If it is, drain 20–30% and repeat commissioning steps.

      RCD Tripping

      • Possible Cause: RCD trips when the cylinder is switched on.
      • Solution: Check all mains wiring to the PV switch, diverter, and cylinder immersion.

      4. Heat Pump Kit Issues

      See 'Setting the heat pump interface' walkthrough as part of Mixergy Training with Roy Fugler. 

      Heat Pump DHW Sensor Reading Incorrect or Error Code

      • Possible Cause: Incorrect heat pump interface DIP switch settings.
      • Solution:
        • Check resistance readings between COM and HOT or COLD.
        • Reset DIP switches to correct resistance and confirm via measurement.

      Immersion Heater Energized During a Call for Heat

      • Possible Cause: Cylinder not set to operate with the heat pump.
      • Solution: Reset the default heat source to "heat pump."

      Slow Cylinder Charging via Heat Pump

      • Possible Cause: Plate heat exchanger circulator pump issue.
      • Solution: Check that the pump is running and set to the correct setting (3).