Coffee machine overfilling and flooding.

If the coffee machine floods overnight when switched off the boiler fill solenoid will need replacing.

Isolate the machine from the mains electricity and water supply before attempting any work.

Replacing the solenoid is not a difficult job but you will need a few spanners and some thread sealer just as an added precaution.

Replace the old solenoid with the new one making sure you check the direction of flow.

If you forget then the higher-pressure side goes to the side of the nucleus where it can’t force the solenoid open, in the case of a boiler fill solenoid it’s the mains water in which is the higher pressure. The side with the small hole is the out to the boiler.

Over filling only when the machine is switched on can have a few causes.

  1. Make absolutely the machine has a good earth/ground and the boiler has a good earth/ground, the control unit uses the earth or ground as a reference point.

  2. Remove the depth probe from the boiler, remove the whole assembly as only pulling out the probe can damage the Teflon seal. You can’t damage the probe other than bending it so scrape off any scale, as the scale builds so does the water level. Check all cables and connections to the control unit.

To remove the assembly a sharp tap on the side of the spanner to shock the joint is better than a slow pull as this can kink the boiler.

  1. If none of the above correct the problem then it’s the actual control unit at fault.

When ordering a new unit always check the makers codes/part number as all electronic units cannot be returned for credit or replacement, this is because faults on the machine can cause the control unit to fail.

Goes with Boiler fill solenoids 

0155 – 0154 – 0484 – 0776 – 1337 – 1356 – 1381 – 1465 -  1890 – 2103 – 2107 – 2365 – 2616 – 3421 – 4035 – 5038 – 8110 – 19363 – 8682 – 9975 – 17623