Delivery
There are two options available, the MW range and the EW range.
The MW is supplied with the following:
MW unvented water heater (with factory-fitted T + P valve)
x1
Wall bracket
x1
Tundish
x1
Dielectric junction
x2
The EW is supplied with the following:
EW unvented water heater
x1
Wall bracket
x1
Pressure relief valve set at 6 bar
x1
Dielectric junction
x2
How the heater works
The heating element is controlled by a capillary thermostat . The operating
temperature can be adjusted by the regulation knob on the front of the heater.
In addition to the thermostat there is a thermal cut-out which is set to switch off
the power to the element if the thermostat fails and the water temperature rises
too high. Once the cut-out operates it can only be reset manually (this should be
carried out by the installer - see maintenance).
A magnesium anode is provided to prevent corrosion of the water container. The
MW has a temperature and pressure relief valve on top of the heater which is a
safety device to back-up the thermostat and thermal cut-out. It works by sensing
an excess water temperature or pressure and releasing the hot water to the
discharge tundish and drain.
The heater will only work in the vertical position as the element is shaped to heat
the water at the bottom of the tank. The inlet pipe needs to deliver cold water to
the bottom of the tank and the hot water outlet draws water from the top of the
tank.
When water is heated it expands. In a small unvented water heater of this type the
expansion can normally be accommodated back into the cold water mains, as
indicated in the Water Regulations.
Where this is not possible the installer will need to fit a set of cold water controls.
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