What it does

The probe is an insulated metal rod that reaches down into the steam boiler. While its tip is under water, a small current passes between the tip and the boiler wall and the electronics read the boiler as full. When steaming or drawing hot water drops the level below the tip, the contact breaks and the pump tops the boiler back up.

Signs it needs attention

Scale is the usual problem. A coated probe can no longer sense the water properly, so the pump keeps running and the boiler overfills, which shows up as water spitting from the steam wand or the pump running on far longer than normal. A lightly scaled probe can often be pulled and cleaned, but one with heavy buildup or damaged insulation is better replaced.

Because the probe works by conductivity, it also needs some minerals in the water. Fully demineralised water, such as distilled water, can leave it unable to detect the water level at all.

Fitting

Work on a cold, unplugged machine with the boiler fully depressurised. Pull the cable off the probe, unscrew the old probe from the boiler and fit the new one, then reconnect the cable. On first start, open the hot water tap until water runs so the boiler refills and any trapped air is pushed out.

Specifications

Fitment

Profitec lists this probe under the same part number in its parts diagrams for the Pro 300, Pro 500, Pro 600, MOVE and the Profitec Ride. It is also used in a number of ECM machines. If your machine is older or not listed here, check the part number against your own parts diagram before ordering, or send us your serial number and we will check it for you.