Ariston Microgenus 32HE MFFI - no heating or hot water
- The boiler pump is working but after 5 seconds the boiler goes into a lock out with an error code E34.
- Open the boiler casing and reset the boiler
- Check the voltage to the boiler fan.
- Check resistance between neutral and live terminals on the fan. A working fan should have around 40 Ohms resistance. A faulty fan will have around 2 Ohms.
- If voltage to the fan is 240V then replace the fan
- The part number is 65102567 for 28kw model
- Completely isolate the electricity to the boiler when replacing the fan
|< Go Back||2017-03-02|
- ARISTON FLUE KIT (HORIZONTAL) STANDARD EFFICIENCY 3318000
|< Go Back||2015-05-23|
Ariston Microgenus 23 MFFI combi boiler has an intermittent heating and hot water (normally in the evenings)
- Boiler doesn't start and needs to be switched on and off several times before it fires up
- Pump is running
- Fan doesn't run
- There is no power to the fan
- Replace PCB - the part number is ARISTON PCB (CMP3-MCU HS MI/FFI) 65101732 (REPLACES 996163, 998642, 998947) (MICROGENUS 23 & 27)
|< Go Back||2014-10-17|
Ariston Microcombi 23 MFFI combi boiler doesn't fire up, no warning ligth and it doesn't reset
- The pump is not running
- The fan is not running
- Reset button doesn't do anything
- Remove 2 grey wires from Low water pressure switch inside the boiler and connect them bypassing the switch
- If boiler fires up then replace the part: Ariston Low water pressure switch 995903
|< Go Back||2014-06-12|
Ariston Microcombi 23 MFFI boiler doesn't work
- No heating or hot water are working
- The power light and the central heating light on the front panel are on
- Boiler pressure is normal and the low pressure switch is not faulty
- If the pump doesn't run then replace PCB
- replacement part is: Ariston 65100248 PRINTED CIRCUIT BOARD
- Replaces 999952 (old part number)
|< Go Back||2014-06-11|
Ariston Microgenus 23 MFFI - no heating and hot water. A red pump fault indicator is lit on a dash board.
- The pump replacement part number is 996614
|< Go Back||2014-01-02|
Ariston Microgenus 23 MFFI - Knocking and rattling noise coming from the gas valve when hot water is running but apart from that the boiler is working fine.
- This is a PCB fault.
- Replacement part number is 65101732 (replaces 996163, 998642, 998947) designed to fit an Ariston Microgenus 23 and 27 MFFI CE gas combination boiler.
- The part number 65103422 (REPLACES 65102571) (Microgenus HE 24,28 & 32) - doesn't work for this boiler
|< Go Back||2013-11-09|
Ariston Microgenus HE combi boiler displays fault code A03 and doesn't reset. After the reset button pressed the error code stays the same and the pump starts running.
- A03 fault code means that the flow temperature exceeds 103oC.
- If pump is working fine then it's likely that the problem is an overheat stat.
- Remove the left side panel for access.
- Put a wire bridge between overheat stat contacts and if the boiler starts working then the overheat stat need to be replaced.
- In my case when I swapped the contacts to the overheat stat the boiler started to work fine.
|< Go Back||2013-08-20|
The boiler doesn’t produce any hot water at all but the temperature on a dashboard remains at 80oC.
- The problem is hot water temperature probe is faulty
- Open the boiler cover and pull the connection to the thermistor out
- The thermistor is located on a diverter valve on the right hand side of the boiler
- Once you pulled it out, open the hot water tap. The boiler should start working.
- Don’t leave it working this way because it will go to overheat lock out after some time as it doesn't know the water temperature at the moment
- To fix the boiler you need to isolate flow and return pipes and drain the boiler in order to replace the thermistor
- The part number for replacement is 998458
|< Go Back||2013-06-27|
Ariston MicroGenus II 28 MFFI mechanical clock doesn't work on timer. If you can hear the clock ticking but it very stiff to turn or you can not hear its ticking then the clock need replacement. Also do the following check. Set the time on the clock and remember it. Then check the time after one hour. If the clock didn't move then its faulty. Before replacing the clock isolate the electrical supply to the boiler by removing the fuse from the boiler switch. The part number is 999599 and you can order it from here. To replace this part you don't need a gas engineer.
Ariston MicroGenus II 28 MFFI manual: PDF
|< Go Back||2013-03-20|
The water from a hot tap is lukewarm and keeps fluctuating. First of all we need to check the burner pressure of the boiler. Remove the from cover and connect the U-gauge to a P2 test point on a gas valve. Open the hot tap and with the boiler on check the burner pressure. It should be 11 mbar. If it is then we need to test the hot water thermistor. Unplug the wire and measure resistance between two connectors. It should be 12 kOhms at 12°C. If it is then we need to test the plate heat exchanger. Open a hot tap and touch the heat exchanger. If within 20 seconds it gets scalding hot then its blocked and need cleaning or replacing. The part number for the heat exchanger is 571646 and can be ordered from here.
Boiler manual: PDF
|< Go Back||2013-02-28|
Ariston Microgenus HE Combi Boiler works for 7 seconds and then goes to a lock-out with a fault code A01 on a screen
- Turn the central heating or hot water on
- remove the front cover and watch the spark electrodes
- If they continue to spark after the flame is present then check the flame sensing electrode (the left hand side one)
- if it looks intact then check the wire from it to PCB for continuity with a multimeter
- If there is a continuity then replace a PCB
- The replacement part number is ARISTON PCB (PRINTED CIRCUIT BOARD) 65103422 (REPLACES 65102571) (MICROGENUS HE 24,28 & 32)
|< Go Back||2013-01-27|