It is essential that the cylinder unit is serviced at least once a year by a qualified individual. Any required parts should be purchased from Mitsubishi Electric. NEVER bypass

safety devices or operate the unit without them being fully operational. For more details, refer to service handbook.

Notes

▪ W ithin the first couple of months of installation, remove and clean the cylinder unit's strainer plus any additional filter items that are fitted external to the

cylinder unit. This is especially important when installing on an old/existing pipe work system.

▪ The PRV valve and T&P valve (No. 8, 20 and 21 on Figure 3.1) should be checked annually by turning the knob manually so that the medium is discharged,

thus cleaning the seal seat.

In addition to annual servicing it is necessary to replace or inspect some parts after a certain period of system operation. Please see tables below for detailed instructions.

Replacement and inspection of parts should always be done by a competent person with relevant training and qualifications.

Parts which require regular replacement

Parts

Pressure relief valve (PRV)

Manometer

Inlet control group (ICG)*

OPTIONAL PARTS for UK

WARNING: DRAINED WATER MAY BE VERY HOT

1. Before attempting to drain the cylinder unit isolate from the electrical supply to prevent the immersion and booster heaters burning out.

2. Isolate cold water feed to DHW tank.

3. Open a hot water tap to allow draining without creating a vacuum.

4. Attach a hose to the DHW tank drain cocks (No. 22 and 23 on Figure 7.1). The hose should be able to withstand heat as the draining water could be very hot. The hose

should drain to a place lower than the DHW tank bottom to encourage siphoning. Begin draining by opening drain cock.

5. When the DHW tank is drained close drain cock and hot tap.

6. For primary circuit, attach hose to water circuit drain cocks (No. 6 on Figure 3.1). The hose should be able to withstand heat as the draining water could be very hot. The

hose should drain to a place lower than the drain cock to encourage siphoning. Open the pump valves and the strainer valves.

7. Water remains in the strainer still after the cylinder unit was drained.

Drain the strainer by removing the strainer cover.

Replace every Possible failures

6 years

Water leakage

Parts which require regular inspection

Parts

Pressure relief valve (3bar)

Temperature and pressure

relief valve

Immersion heater