Hot Water
Energy
Storage
Unvented Cylinder
Installation & Maintenance Instructions for an unvented
hot water cylinder with internal thermal expansion
SEPT 2018
20
Before commencing work to remove the immersion heater ensure the cylinder is fully
drained of water. Refer to the installation manual for guidance. Ensure heating con-
trols are turned off.
This bulletin features an indirect model, so the thermostat enclosure contains thermo-
stats for immersion element and boiler control. For direct models discount the boiler
thermostat as it wont be fitted (this is shown on the LHS in Figure.1).
WARNING! DANGER OF ELECTRIC SHOCK! DO NOT remove thermostat enclosure
without isolating the supply to the product. If in doubt do not continue and seek ad-
vice from a competent electrician.
Immersion Heater Key – supplied
with install manual or fitted to
preplumbed pipework.
Long shafted screwdriver
Do NOT remove cover without isolating the supply to the product.
• Locate thermostat enclosure on cylinder. Loosen screw (circled on photograph) that
holds front cover on to back plate.
• Remove cover to reveal the thermostats and the associated wiring.
• Remove power and earth cables
• Remove thermostat bulbs from element pockets.
• Use the Immersion heater key to unscrew the brass restraining nut.
• Remove the nut and withdraw the element.
•
Prepare new element. Always fit a new seal on an element. DO NOT REUSE SEALS. En
-
sure seals are not distorted and free from dirt, tears and imperfections. The seal should
sit flush on the element plate and have good surface contact. If any imperfections are
present on the seal, discard and replace.
• The lip of the seal should be fully engaged around the edge of the plate.
The longer seal lip should be on the water side of the element plate
WATER
Immersion Heater Replacement