Product specifications

7.9.Connecting the domestic hot water supply.
The cold water inlet and hot water outlet
connection points for supplying domestic hot water
are located on the underside of the appliance (Fig
20). The cold water inlet (K) is colour coded blue,
the hot water outlet (W) colour coded red, and both
are 15mm.
Figure 20: Mains-side hot & cold water
connections.
The cold water inlet to the boiler must be made via
the UV3 manifold. The hot water supply to the
property is connected to the boiler via the 15mm
diameter hot water outlet connection.
As the boiler's minimum domestic hot water
temperature setting is 60°C., the installation of a
thermostatic mixing valve is necessary to reduce
he hot water temperature at the tap. t
7.10 Hot water secondary circulation.
While there is no separate secondary return
connection on the boiler, a secondary re-circulation
loop may be installed. Where required, the
secondary return should be taken to the cold water
feed of the storage tank, immediately after the UV3
manifold. The return must not pass through the
UV3 manifold. If the secondary return loop has a
volume in excess of 1 litre, a larger potable
expansion vessel should be used. Contact Atmos
Heating Systems for further advice.
A non-return valve must be fitted to the return loop
to prevent the back flow of cold water to the hot
water taps. (Fig 20a
)
Figure 20a Hot water secondary circulation
7.11.Connecting the gas supply.
The gas pipe inlet connection is located on the
underside of the appliance being colour coded in
yellow (G). (Fig 21).
Figure 21: Gas inlet connection
Check the boiler's data plate to ensure that the
appliance has been set for the correct gas supply.
The boiler is available for either Natural Gas (G20)
or propane (G31).
For Natural gas, the supply pipe must have a
minimum diameter of 22mm. The meter governor
should deliver a dynamic pressure of 20mbar for
natural gas or 37mbar for propane.
ATMOS MULTI Mk 2 version 2008
Page 30