System Details - Baxi System 100 HE Plus Installation & Servicing Instructions Manual

Switch live from
programmer, etc.
N
S/L
Filter
Optional
Pump
Feed
N
S/L
Boiler
Connections
Fig. A Wiring an extra pump to the pump feed
connection of boiler
Boiler
Live feed to
pump

6.0 System Details

6.1 Water Circulating Systems
1. The appliance is suitable for fully pumped sealed systems
Hot water
only.
The following conditions should be observed on all systems:
• The boiler must not be used with a direct cylinder.
• Drain cocks should be fitted to all system low points.
Central
• All gas and water pipes and electrical wiring must be installed
heating
load in a way which would not restrict the servicing of the boiler.
• Air vents should be fitted to all system high points.
• An air rejection separator is recommended to ensure correct
operation of all appliance components.
2. If the system requires an output from the boiler greater than
75,000 Btu/hr then an additional external pump will need to be
fitted.
3. If the system is fully TRV'd with no bypass then any external
pump can be wired back to the boiler Optional Pump Feed
connection. This will protect the pump by turning it off if all the
TRVs are shut (sensed by the boiler flow switch). This is wired
as in Fig. A. See section 8.7 for how to increase boiler output
from 75.000 Btu/hr to 100,000 Btu/hr.
6.2 Treatment of Water Circulating Systems
• All recirculatory water systems will be subject to corrosion
unless an appropriate water treatment is applied. This means that
the efficiency of the system will deteriorate as corrosion sludge
accumulates within the system, risking damage to pump and valves,
boiler noise and circulation problems.
• When upgrading existing systems that exhibit evidence of
sludging, it is advisable to clean the system prior to treatment in
order to remove any sludge and reduce the likelihood of these
deposits damaging new components.
• When fitting new systems flux will be evident within the system,
which can lead to damage of system components.
• All systems must be thoroughly drained and flushed out. The
recommended flushing and cleansing agents are Betz-Dearborn
Sentinel X300 or X400 and Fernox Superfloc Universal Cleanser
which should be used following the flushing agent manufacturer's
instructions.
• System additives - corrosion inhibitors and flushing
agents/descalers should be suitable for aluminium and comply to
BS7593 requirements. The only system additives recommended
are Betz-Dearborn Sentinel X100 and Fernox-Copal which should
be used following the inhibitor manufacturer's instructions.
Failure to flush and add inhibitor to the system will invalidate
the appliance warranty.
• It is important to check the inhibitor concentration after
installation, system modification and at every service in accordance
with the manufacturer's instructions. (Test kits are available from
inhibitor stockists.)
• For information or advice regarding any of the above contact the
Baxi Helpline.
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