Product specifications

Where required, the boiler offers the facility for an
independent towel rail circuit to be installed via the
extra central heating connection (Connection O in
Fig 11). This allows for the separate heating of a
radiator when the boiler is operating in either
central heating or hot water mode, with a maximum
power of 5kW. To prevent hot water circulation
within the central heating system when the boiler is
operating in domestic hot water only mode, the
towel rail circuit return must be the last connection
on the return pipe to the boiler. The heating of the
towel rail should be controlled by a thermostatic
radiator valve.
Note. When utilised, the towel rail circuit must be
carefully balanced to avoid short-circuiting of the
main central heating system.
A 'Robokit' sealed system kit is required for the
Atmos Multi boiler. The kits with filler loop and
RED expansion vessel in 8,12 or 18 litre sizes are
available from Atmos Heating Systems.
Table 5 provides guidance to the size of expansion
vessel required for systems fitted with steel panel
radiators in a two-storey house. Consult Atmos
Heating Systems for further information and advice
for non-standard systems.
Note. The red primary expansion vessel must not
be confused with the white secondary expansion
vessel intended for use on the domestic hot water
circuit.
Table 5: Required expansion vessel
Expansion
vessel
size in
litres
System
primary
water
capacity
Approx
system
output
Approx
no of
radiators
8 90 litres 10kw (34,000
Btu/hr)
8
12 140 litres 15kw (51,000
Btu/hr)
12
18 200 litres 20kw (68,000
Btu/hr)
18
ATMOS MULTI Mk 2 version 2008
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