4. Plumbing Installation
4.1. Connections
. Connections
MUST
be made to the cylinder in accordance with Fig 1, and Fig 2.
A drain cock (not supplied) should be fitted in the position shown in Fig 1 to facilitate draining of the
cylinder.
4.2
.
Cold water supply –
For best results, the cylinder should be fed by an uninterrupted 15mm
supply pipe into the pressure reducing valve (PRV) with a supply pressure of between 3 and 12 bar
maximum. The cylinder should not be used on any system with a supply pressure below 1.5 bar and a
flow rate of less than 20 litres per minute.
4.3. Temperature and pressure relief valve
– The temperature and pressure relief valve (T&P Valve)
is supplied factory fitted to the cylinder. The T&P Valve must not be removed from the cylinder or
tampered with in any way. The valve is pre calibrated to lift at 7 bar or 90 degrees centigrade and any
attempt to adjust it will invalidate the warranty and could affect the safety performance of the unit.
The outlet of the T&P valve should be routed in 15mm copper piping in a downward direction
alongside the water heating unit to the tundish. The outlet of the expansion relief valve must be T’d
into this pipe before the tundish so that any water exiting either valve can be seen draining through the
tundish– see fig 2
4.4. Pressure Reducing Valve
– The pressure relief valve should be installed in the cold water supply
to the water heating unit with the arrow pointing in the direction of water flow as shown in figure 5.
This can be connected to a supply pressure of between 1.5 and 12 bar.
4.5 Expansion Relief Valve
this must be installed between the pressure reducing valve and the water
heating unit in accordance with Figure 1. No other valve should be fitted between this valve and the
cylinder.
The expansion relief valve contains a non return valve.
4.6. Expansion vessel –
A suitable expansion vessel with a pre-charge pressure of 3 bar is supplied for
fitting to all water heating units in the range. The expansion vessel
MUST
be fitted between the
expansion relief valve and the cylinder. The expansion vessel
MUST
be positioned with the entry
point at the bottom.
IMPORTANT:
Regular checks must be carried out to ensure that the expansion vessel is correctly
pressurised to 3 bar at all times. The expansion vessel should be installed using a standard t-connector
between the expansion relief valve and the cylinder – see Figure 1.
4.7. Tundish –
The tundish must not be positioned above or in close proximity of any electrical
current carrying devices or wiring. The installation should conform with the requirements of item 7
below.
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