VOKERA Linea Max HE Installation & Servicing Instructions Manual - page 27
Supplied By www.heating spares.co Tel. 0161 620 6677
LINEA MAX HE
23
6.7.8
Setting the Maximum Rate for Central Heating
The maximum heat input for the central heating
mode is not adjustable.
6.8
Checking the Flue System
6.8.1
The flue system should be visually checked for
soundness. Check all clamps and fixings are
secure and tight.
6.9
Checking the Heating Thermistor
6.9.1
Allow the system to warm up and manipulate the
c/h control knob to ensure that the burner modu-
lates between ‘high’ and ‘low’ and then to ‘off’
and vice versa (scale range covers approx. 45° -
85°C).
6.10
Regulating the Central Heating System
6.10.1
Fully open all radiator and circuit valves and run
the appliance in the central heating mode until
heated water is circulating. If conditions are
warm, remove any thermostatic valve heads.
6.10.2
If the burner will not light, ensure that water is in
fact circulating. See 4.6.3.
6.10.3
Adjust radiator return valves and any branch cir-
cuit return valves until the individual return tem-
peratures are correct and are approximately
equal.
6.10.4
When all is adjusted, progressively close all
radiator valves to ensure that the appliance still
operates when flow through the system is limited.
If the burner cuts out prematurely due to lack of
water flow through the appliance, the system
should be regulated to ensure a flow rate of at
least 360 litres/h (78 gals/h). This may mean the
addition of a small manual by-pass being fitted to
the system if a fully TRV system is used.
6.11
Final Flushing of the Heating System
6.11.1
The system should be flushed in accordance with
BS7593:1992. Turn on the boiler for central hea-
ting and allow the boiler and system to reach
temperature. Turn off the boiler and drain the
system whilst hot.
Refill the boiler and heating system as described
in 6.3.3.
Although not necessary for correct operation of
the boiler an inhibitor may be added at this point.
Contact the inhibitor manufacturer for further
information concerning application and required
dose.
6.11.2
Inspect the system for soundness. Turn the
appliance off at the mode selector switch.
6.12
Filling, Testing and Regulating the Domestic
Hot Water System
6.12.1
Start with the appliance switched on having com-
pleted the procedures described in 6.4 to 6.11.
6.12.2
Open a domestic hot water tap (Preferably the
bath tap).
Ensure cold water inlet stopcock is fully open
(horizontally to the right) and the dhw control
knob is set at maximum.
6.12.3
The flow of water should activate the domestic
hot water flow switch (13) and drive the diverting
valve (21) to its hot water position thus heating
the domestic water flowing through the dhw heat
exchanger. At the same time the pump and fan
are activated lighting the burner on maximum
rate.
6.12.4
If the burner does not light, check that the water
flow rate is above the minimum required to ope-
rate the domestic hot water flow switch (13) 2.0
litres/min (0.45 gals/min).
6.12.5
The temperature of the water will depend on the
rate at which it flows and the amount of energy
stored in the primary store.
The temperature of water at the tap can be varied
by adjusting the water flow rate at the tap up to
the maximum predetermined quantity.The hot
water temperature control knob will govern the
maximum temperature. When the appliance is
being used in hot water mode the temperature
indicator indicates the temperature of the hot
water leaving the appliance.
6.12.6
It is best to set for the lowest acceptable tempe-
rature since the user can gain higher temperatu-
res by restricting flow at the tap.
N.B. If the cold supply is subject to large fluctua-
tions or is above the permitted maximum a suita-
ble pressure/flow regulator should be fitted in the
cold water supply to the appliance.
6.12.7
Turn the appliance mode selector switch to the
position.
Slowly close the tap to reduce the rate of draw to
above the minimum approx. 2.0 litres/min., (0.45
gal/min.) Rotate the dhw control knob to ensure
the appliance modulates at its various setting.
6.12.8
Close the draw-off tap still further. The burner
should stop when the rate falls below approxima-
tely 2.0 litres/min. (0.45 gal/min.), and the primary
store temperature is replenished.
6.12.9
The appliance incorporates a hot water preheat
facility. The appliance will therefore ignite periodi-
cally to maintain heat within the thermal store of
the appliance.
6.12.10
Flow Restrictor
The appliance is fitted with a flow rate restrictor
that limits the maximum flow rate that can be
drawn through the appliance. The restrictor elimi-
nates the need to manually adjust the DHW flow
rate. Flow-rate (18 l/min).
6.13
Final Check for Operations
Turn mode selector switch to the OFF/RESET
position, disconnect pressure gauge, re-tighten
screw. Relight boiler.
6.13.1
Re-check for gas soundness
6.13.2
Re examine heating and hot water systems and
cold water supply for water soundness.
6.13.3
Check the appearance of the gas flame to assess
adequacy of combustion air supply.
6.13.4
Re-check the flue system for soundness and ade-
quacy of supports.