MAINTENANCE MANUAL
Mirage technical manual
page 39 of 65
Clean probes, level and safety
Two probes are mounted in the hot water/steam boiler. The probe with the orange wire checks the
water safety level. Power to the heating elements in the Mirage is disconnected when water level is
lower than this probe. The probe with the white wire checks the water level in the steam boiler for
normal operation; when water level is below the probe, the boiler will start filling with the pump
engaged, provided that no shot is being pulled. The boiler stops filling when water level reaches the
probe.
The controller sends an electrical current (appr. 1.2VAC high frequency) to the probes and checks if
water in the boiler “closes” the electrical circuit or not. Precipitation on the probes may act as
(electrical) insulation which prevents proper functioning of the probes.
Cleaning the probes requires that pressure is released from the steam boiler.
Figure M 18a (left). Water level probes as seen from back of machine. The probe with the white wire
(operational level) protrudes 45 mm above the boiler, the probe with the orange wire (safety level) is
pushed down as far as possible.
Figure M 18b (right). New water level probes. The upper (longer) probe is the safety level probe and
has been taken apart to show the Teflon sealing. The lower (shorter) probe is the operating level
probe.
Materials needed
Allen key 3 mm
Spanner 12 mm, 17 mm
Procedure
1. Switch power off.
2. Open steam valve(s) until no more steam escapes the machine. This is to release pressure from
the steam boiler, shut valve(s) when pressure is fully relieved.
3. Remove cup warmer.
4. Pull electrical connections from probes, then remove probes from boiler.
Note!
Loosen the inner fittings (small nuts). The inner nut squeezes a Teflon seal on the probe. When the
probes are not too dirty, they can probably be pulled through the Teflon seal, otherwise, the Teflon
seal will be pulled out of the outer fitting, either one is O.K.
5. Clean the metal end of the probes with a well-used plastic scrub pad. Scale and dirt adheres
better on a rough surface: try not to scratch the probes.
45
mm
operational
safety
operational
safety
Teflon seal