Product specifications

8. Commissioning.
8.1 Filling the heating system.
Warning! The Atmos Multi must not be operated
without filling with water.
Warning! All new and existing systems must be
thoroughly drained and flushed out in
accordance with BS7593 requirements. A
suitable cleaning agent is Sentinel X400,
following the manufacturer’s instructions. A
corrosion inhibitor should be added and the
concentration level checked. The only suitable
product recommended by Atmos is Sentinel
X100, following the manufacturer’s instructions.
Atmos do not recommend any other inhibitor.
On completion of the boiler installation and
ensuring that all water connections are correctly
made and tight, the boiler may be filled with clean
water by fitting the supplied filling hose and
opening the manual filling valves, or in the case of
the optional Pre-Assembled Pipework kit, open the
cold fill valve in the filling loop.
On filling:-
 Ensure that the boiler's automatic air vent
sealing cap is loose.
 Slowly fill the installation until a system
pressure of 1.5 bar is obtained.
 Vent each radiator and purpose fitted air vent in
turn starting with the lowest in the system. The
system pressure should be regularly monitored
during this process and topped up when required.
 Air must be vented from the boiler pump by
unscrewing the pump’s integral vent plug (Fig 26)
and allowing water to bleed for a few seconds,
taking care not to allow water to splash onto the
boiler's electric parts. This process may have to be
repeated two or three times during the filling
process.
 Check that the pump shaft rotates freely:-
With the plug out, insert a narrow flat screwdriver
into the end of the shaft and rotate. Replace the
plug.
Figure26: Venting the pump
Note: The appliance must be installed and
commissioned in accordance with the
manufacturer’s instructions in order to comply
with the Building Regs. To
demonstrate
compliance, the Benchmark Checklist
(located at the back of this Manual) should be
completed and signed at the time of
commissioning, and left with the customer.
Failure to flush and add a suitable
inhibitor to the system will invalidate the
Appliance Warranty.

Test the operation of the heating system’s 3 bar
safety valve by turning the valve knob anti-
clockwise until water is released, at which point the
valve must be closed.
 Continue to fill the system until all air has been
expelled, leaving the system pressure at a nominal
1.5bar.
 Check the system for water leaks, rectifying
where necessary and disconnect the system filling
hose.
 If using a pressure differential regulator valve
(supplied by Atmos) for the bypass, set to 0.2
Note: For the optional Pre-Assembled Pipework
kit, the bypass is included and should be set to 0.1
Figure 27: Three-way valve
NOTE!
To aid filling, the boiler is supplied with its integral
three way valve locked in the middle position.
Once full, the valve must be unlocked by lightly
pressing and then pulling the black button located
on the rear of the valve. (Fig. 27). The three way
valve will then return to the 'Auto' position.
ATMOS MULTI Mk 2 version 2008
Page 35