Table of Contents
Advertisement
4
Installation
Immersion heater
When an immersion heater is fitted, do NOT energise the heater until the DHW tank is full of water. Also do NOT energise any immersion heater if any sterilisation chemicals
remain in the DHW tank as this will cause premature failure of the heater.
Safety Device Connections
The expansion relief valve on the secondary hot water side, and the temperature
and pressure (T&P) relief valve (*A), both need appropriate discharge pipework.
There must be no valve fitted between the expansion relief valve and the tank.
*A EHPT20X-MEHEW is equipped with factory-fitted T & P relief valve on the
tank (2). Any other models are equipped with Pressure relief valve, fitted to the
DHW pipework (3).
Note : 1. Do not secure the screws excessively when connecting the Discharge
pipe, otherwise it may result in damage to the cylinder unit.
<For UK>
The right side panel has a plate (*B) so that connection can be made to the factory
fitted temperature and pressure relief valve. If you wish to make the connection in
a different position you will have to cut a hole in the side panel yourself. However
it remains necessary that the drainage parameters outlined in the appropriate
Building Regulations are complied with.
*B Unscrew the plate on the right-side panel, connect the Pressure relief valve to
the discharge pipework, and refit the plate. Always replace the plate so that no
gaps exist between the plate and side panel and the plate and drain pipe to
avoid heat loss.
In accordance with Building Regulations a tundish must be fitted into the pipe-
work within 500 mm of the safety device (also see Figure 4.4.1). Due to the
distance between the two safety devices it may be necessary to fit each safe-
ty device with its own tundish before you run the pipework together to a safe
discharge (see Figure 4.3.6).
Note : 2. Alternatively the discharges from the expansion relief valve and
T&P relief valve may commonly discharge to a singular tundish, so
long as this tundish is located within 500 mm of the T&P relief valve
in UK. When connecting discharge pipes to the safety devices, be-
ware not to strain the inlet connections.
Diagram
Description
part No.
Expansion relief valve
1
(part of inlet control group)
T&P relief valve
2
3
Pressure relief valve
<Table 4.3.2>
Always refer to local regulations when installing discharge pipework.
Install discharge pipework in a frost-free environment.
It is necessary to provide appropriate drainage from the pressure relief valve
situated on top of the cylinder unit to prevent damage to the unit and the sur-
rounding area from any steam or hot water released. Relief valves MUST
NOT be used for any other purpose.
For UK use WK02UK-E kit, for other countries please see below;
• Any discharge pipework should be capable of withstanding discharge of hot
water. Discharge pipework should be installed in a continuously downward di-
rection. Discharge pipework must be left open to the environment.
Piping diagram for 2-zone temperature control
Connect the pipe work and locally supplied parts according to the relevant circuit diagram shown in Section 3. Technical Information, of this manual.
For more details on wiring, refer to "5.3 Wiring for 2-zone temperature control".
Note: Do not install the thermistors on the mixing tank. This could affect correct monitoring of flow and return temperatures through each zone.
Install the Zone2 flow temp. thermistor (THW8) near the mixing valve.
Connection
Connection
size
type
15 mm
Compression
15 mm /G 1/2
Compression/
Female
G 1/2
Female
<UK model>
EHPT20X-MEHEW
DHW
2
<Other models>
The expansion vessel on the sanitary water side shall
be installed as necessary in accordance with your lo-
cal regulations.
3
DHW
<Figure 4.3.6>
1
Cold water inlet
Tundish
Cold water inlet
en
14
Advertisement
Table of Contents
