MAINTENANCE MANUAL
Mirage technical manual
page 25 of 65
Anti-vacuum valve
Water inside the steam boiler cools down when the machine is shut off. While cooling down, the water
contracts which leads to a decreased boiler pressure. The anti-vacuum valve prohibits that under-
pressure occurs in the steam boiler. The anti-vacuum valve could malfunction when the machine is
turned off regularly. It is advised to replace the anti-vacuum valve every year.
Some sputter and hiss inside the drain pipe at the back of the drip tray is normal when the machine is
warming up from cold when the water reaches boiling temperature and a little steam is released
through the anti-vacuum valve into the discharge.
A malfunction of the anti-vacuum valve is recognised by a continuous hissing sound combined with
the lack of pressure and temperature building up while the heater in the steam/hot water boiler is
engaged continuously and the boiler is filled automatically once in a while. (However, a malfunctioning
safety valve leads to similar symptoms.)
The machine can remain operational when checking the anti-vacuum valve for leakage. However, it
must be shut down and pressure from the boiler must be fully released before the anti-vacuum valve
can be replaced.
Check anti-vacuum valve
Materials needed
Allen key 3 mm
Procedure
1. Remove cup warmer.
2. Pull black drain hose from anti-vacuum valve (see figure M 9).
3. Check for leakage, the hose should be dry and should not show evidence for leakage (detrital
build-up) on the inside.
4. If necessary, replace anti-vacuum valve (see below).
5. Remount hose.
6. Remount cup warmer.
Replace anti-vacuum valve
Materials needed
Spanner 13 mm, 16 mm, 17 mm
Socket wrench 17 mm
Allen key 3 mm
Replacement anti-vacuum valve and copper O-ring ¼
Procedure
1. Turn Mirage
“off”.
2. Open the steam valves, this will relieve the pressure in the hot water/steam boiler.
3. Remove cup warmer.
4. When all pressure is relieved, pull the black silicone (drain-) hose from the anti-vacuum valve (see
Figure M 10). The white adapter shown on the photo hardens over time and may crack or break.
For that reason the adapter is no longer installed, the hose connects directly onto the anti-vacuum
valve.
5. Unscrew the anti-vacuum valve from the boiler with a 17 mm socket wrench. Loctite is used for
sealing, a little extra torque may be needed.