Installation requirements
Regulations governing installation
Alkon boilers should be installed in accordance with all
prevailing regulations and codes of practice, including the
Building Regulations, Health and Safety Regulations PM5,
Water Bylaws and the current Gas Safety (Installation and
Use) Regulations. Detailed relevant guidance will also be
found in;
BS 6644 :2005 Installation of appliances exceeding 70
kW net input
BS 5449 Forced circulation hot water central
heating systems for domestic premises
CIBSE AM14: 2010 Non-domestic hot water heating
systems
CIBSE Guides B and C and Commissioning Code B
Institution of Gas Engineers Utilization Procedures 1, 1A,
2, 4, 7 and 10.
Water treatment
Alkon 90 boilers have an aluminium/silicon/magnesium
alloy heat exchanger and care must be exercised to
ensure that the system water and any water treatment is
compatible.
Whenever a new boiler is connected to an existing
system, the pipework must be thoroughly cleaned and
flushed. This is to remove debris, rust particles, carbonate
deposits and any existing water treatment that might be
incompatible with the heat exchanger. New systems must
also be thoroughly flushed to remove debris and flux
deposits. Clyde recommend that a permanent means of
filtration be fitted into the return pipework, such as a
sludge trap, hydrocyclone or full flow duplex filters. The
boiler guarantee will be invalid if waterways are blocked
by debris or carbonate deposits.
The pH value of the system water should be measured to
ensure that it is between 6.5 and 8. Temporary hardness
(calcium carbonate and magnesium carbonate) can be
removed by boiling and its effects limited by preventing
ingress of fresh, untreated water. Permanent hardness
must not exceed 15oFR (150 mg/litre calcium carbonate).
The boiler guarantee will be invalidated by the use of
incorrect or incompatible water treatment. Specialist
advice should be obtained, eg from;
Fernox Tel. 01483 793200
For full information on cleaning, flushing and protecting
hot water systems, refer to BSRIA Application Guide AG
1/2001.
Deaeration
It is a condition of warranty that there is effective air
separation and removal from the system. The air
separator should be fitted at the hottest part of the system.
Boiler condensate
Alkon 90 boilers have a 32 mm flexible condensate drain
that is compatible with standard plastic waste pipe. Do
not use other materials, as they will corrode. The pipe
size must not be reduced and there must be a continuous
fall to drain. As a further precaution against freezing,
condensate pipes should be run internally whenever
possible and lagged when run externally.
Pressurisation of systems
Alkon 90 boilers should be installed as part of a
pressurised (sealed) or open vented system with a
minimum pressure of 0.5 bar. The maximum allowable
pressure for the boilers is 8 bar. They are not to be used
with a gravity circulation system.
Boiler location
Alkon 90 boilers can be installed external to a building if
the optional top weather cover is fitted. The boiler must
be mounted on a sound, smooth and level plinth of non-
combustible material, capable of supporting its weight.
The boiler location must be frost-free and adequately
ventilated (see below). Contamination of the combustion
air by inflammable vapours, high dust levels or
halogenated hydrocarbons will constitute a safety hazard
and will damage the boiler.
The following minimum clearances around the boiler
should be observed;
Front 500 mm
Sides 500 mm
Air supply and ventilation
Adequate air for combustion and ventilation is essential to
the safe operation of a boiler. The air for combustion and
ventilation requirements of either BS 6644:2005 or
IGEM/UP/10 must be met. Table 1 shows the
requirements of BS 6644:2005 for boilers with a Type B
flue. This standard requires natural ventilation at both
high and low levels to the outside air, and is based on the
net input of the boilers.
BS 6644:2005 calls for additional ventilation if a boiler is
used for more than 50% of the time during the summer or
if the ambient temperature of the plant room ceiling
exceeds 40°C.
Ventilation direct to
outside air
Total kW input (net)
Low level 4 cm² per kW of total rated net
input
High level 2 cm² per kW of total rated net
input
Table 1 Ventilation for multiple boiler installations in a boiler
room complying with BS 6644:2005
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