Installation & Maintenance Instructions for an unvented
hot water cylinder with internal thermal expansion
Hot Water
Energy
Storage
Unvented Cylinder
SEPT 2018
21
• Use the long shafted screwdriver or similar tool to support the element when reinsert-
ing into the cylinder. This prevents it moving in the immersion boss.
• Insert the new element into the cylinder.
•
Make sure the element plate is flush against the surface of the boss. Ensure the seal is
still in position and the top pocket for the thermostat bulbs is at 12 o’clock. Holding the
element in place tighten up the brass nut until finger tight.
• Remove the screw driver. Check the plate is seated properly.
• Tighten up the nut using the immersion key
• Apply the correct torque. 14N/m
•
Refill the cylinder to just over the immersion fitting and check for leaks.
• If leaks appear – DO NOT OVER TIGHTEN. Re-drain, remove element and replace seal
• Now replace the thermostat bulbs and wiring. Start by inserting the RHS thermostat
bulb spiral wound first in the top (12o’clock) element pocket
• Then follow this with the RHS solid bulb. Ensure the bulb is fully inserted to the pocket.
•
Insert LHS thermostat bulb spiral wound first in the bottom (6o’clock) element pocket
• Then follow this with the LHS solid bulb. Ensure the bulb is fully inserted to the pocket.
• Attach the electric supply and earth cables.
• Check all wires and thermostat bulbs are in the correct positions.
•
Open a hot outlet and refill cylinder from mains. Allow water to flow out of outlet. Once
a good flow is achieved close outlet.
• When cylinder reaches maximum available pressure. Re-check for leaks.
• Turn hot water programmer back on. Allow cylinder to heat up. Check water is hot and
thermostats are operating.
•
Now at operating temperature, re-check for leaks. After confirming everything is
operating correctly, replace cover.
