A quick reference table for troubleshooting issues when installing and servicing a Mixergy cylinder.
Mixergy cylinders
| Fault | Possible Cause | Solution |
| Milky / cloudy water | Oxygenated Water | Water from any pressurized system will release oxygen bubbles when flowing. The bubbles will settle out. |
| No hot water flow | Cold main off | Check and open stopcock. |
| Strainer blocked in inlet control group | Isolate water supply, strip and clean. | |
| Inlet control group may be fitted incorrectly | Check and refit if required. | |
| Water escaping from the case unit | Compression fitting on pipework not sealing | Check / remake joint. |
| Leaking cylinder | Isolate supply and contact Mixergy technical support via phone (01865 884 343) or through our Website. | |
| Cold water at hot taps. | Heat source not working |
Check heat source - consult boiler / heat pump / solar manufacturer’s instructions. |
| The immersion heater is not switched on or the cutout has triggered | Check / reset. | |
| Motorised valve fault | Check plumbing / wiring to motorized valve. | |
| Circulating pump fault | Check pump and consult manufacturer’s instructions. | |
| Cut-out in dual stat has operated | Reset and investigate cause. | |
|
Water discharges from expansion relief valve |
If continual, pressure reducing valve (part of inlet control group) may not be operating correctly. | Check outlet pressure from inlet control is 3 bar. |
| If continual - expansion relief valve seat may be dirty or damaged | Remove cartridge - check seat, clean and renew if necessary. | |
| If intermittent - expansion vessel charge may have reduced / bladder perished | Check pressure in expansion vessel. Recharge to 3bar if necessary. If bladder perished replace vessel. | |
| Unit is being back pressurized. |
With cylinder cold check pressure in cylinder. If this is the same as the incoming mains pressure then you are getting a back feed. Install a balanced cold supply. |
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Hot water discharges from temperature & pressure relief valve |
Unit has overheated - thermal controls have failed |
Switched off power to boiler / heat pump and immersion heater. Leave water supply on. Wait until discharge stops. Isolate water supply and replace if faulty. |
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Noise during hot water draw off - typically worse in the morning |
Expansion vessel over pressurised |
Check pressure adjust to 3 bar. |
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Hot or warm water from cold tap |
If tap runs cold after a minute or so the pipe may be picking up heat from hot pipework or heating pipework. |
Insulate / re-route. |
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Low Pressure |
Service valve not fully open |
Ensure service valve is fully open. |
| Partially blocked strainer |
Check/clean strainer in pressure reducing valve. |
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| Restricted delivery pipework |
Replace damaged or old pipework. |
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| Low mains pressure |
Check incoming mains pressure or discuss with local water supplier. |
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Water not hot enough |
Boiler not providing enough heat |
Ensure boiler thermostat is set to above 65°C |
| Cylinder thermostat settings incorrect |
Adjust thermostat to between 55°C & 65°C |
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Status LED codes |
Flashing green |
System OK |
| Solid green / red |
System updating. Do not turn power off |
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| Very slow flashing red every 2 seconds – temperature sensor issue |
Check temperature sensor |
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| Slow flashing red once a second – no gauge detected |
Check gauge is plugged in correctly |
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| Fast flashing red twice a second – energy measurement issue |
Contact Mixergy technical support via phone (01865 884 343) or through our Website. |
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| Very fast flashing red, five times a second – unable to detect the presence of the current reader if Mixergy Solar X |
Check the wiring between the cylinder controller, diverter, current reader and current clamp |
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| Very fast flashing red, five times a second – main processor issue |
Contact Mixergy technical support via phone (01865 884 343) or through our Website. |
Solar X
| Fault | Possible Fault | Solution |
| Cylinder always switches the immersion on to full power when diverting | Current clamp has been installed in the wrong direction | Current clamp must be attached around the neutral cable on the incoming mains supply with the arrow pointing towards the incoming supply main fuse. |
| Rapidly flashing red light on the side of the cylinder controller |
Cylinder unable to detect the presence of the current reader | Check the wiring between the cylinder controller, diverter and current clamp. |
PV Switch
| Fault | Possible Fault | Solution |
| 3rd party solar diverter not working correctly | Solar diverter is unable to supply heat to the cylinder | Check the solar diverter is setup correctly according to manufacturer's instructions |
| Check the immersion heater thermostat is adjusted to max | ||
| Check that the cylinder is not entirely full of hot water (i.e. 100% charged). If the cylinder is full of hot water, drain the cylinder down 20-30% and repeat the commissioning steps. | ||
| RCD tripping | RCD is tripping when the cylinder is switched on | Check all mains wiring to the PV switch, diverter and cylinder immersion. |
Heat Pump Kit
| Fault | Possible Fault | Solution |
| Heat pump DHW sensor reading incorrect value or giving an error code | The heat pump interface DIP switches set incorrectly Check resistance reading by measuring between the COM and HOT or COLD |
Reset DIP switches to correct resistance. Confirm by measuring between the COM and HOT or COLD |
| Immersion heater being energised when a call for heat | Cylinder hasn’t been set to operate with the default heat source set as ‘heat pump’ | Check/reset default heat source to ‘heat pump’ |
| Cylinder is charging slowly via heat pump | Heat exchanger circulator pump not running or set incorrectly | Check the heat exchanger circulator pump is running and set to 3 |