UK Manufactured Unvented Hot Water Cylinder Installation Guide
51
Maintenance
General
Servicing should only be carried out by competent installers and any spare parts used must be purchased
from JOULE.
Never bypass any safety devices or operate the unit without
them being fully operational
Draining
Switch the electrical power off (important to avoid damage to element). Isolate boiler from the unit. Turn off
the cold water supply valve. Open hot water tap. Open the drain valve. The unit will drain.
Water drained off may be very hot!
Annual Maintenance
The water heaters require annual servicing in order to ensure safe working and optimum performance. It is
essential that the following checks are performed by a competent installer on an annual basis. This is com-
monly done at the same time as the annual boiler service.
•
Twist the cap of the expansion relief valve on the inlet control set and allow water to flow for 5 seconds.
Release and make sure it resets correctly.
•
Repeat with the pressure / temperature relief valve. In both cases check that the discharge pipework is
carrying the water away adequately. If not, check for blockages etc. and clear.
•
Check that any immersion heaters fitted are working correctly and that they are controlling the water at
a temperature between 55°C and 65°C.
•
Check the pressure in the expansion vessel is charged to 3 bar. Turn off the water supply to the unit and
open a hot tap first. The air valve on expansion vessel is a Schrader (car tyre) type.
•
Air, CO
2
or Nitrogen may be used to charge the expansion vessel. Unscrew the head on the inlet con-
trol set and clean the mesh filter within.
The Service Log Book supplied with this unit should be updated at each service.
Your guarantee may be void if you cannot produce proof of
annual servicing immersion heater replacement.
