Approved Corrosion Inhibitors And Anti-Freeze For Central Heating Water; Possible Sources Of Corrosive Cfcs - Worcester CDi Combi N.G Service Booklet

12.8 APPROVED CORROSION INHIBITORS
AND ANTI-FREEZE FOR CENTRAL
HEATING WATER
CORROSION INHIBITOR
B Add a suitable* inhibitor (or combined inhibitor/anti-
freeze if the system is exposed to freezing conditions)
to the heating system in accordance with the DWTA
Code of Practice and the manufacturers instructions.
*The inhibitor or combined inhibitor/anti-freeze must not
cause damage to the materials within the appliance and
any other materials/components within the system.
Manufacturer
Fernox 01799 550811
Sentinal 1800 882 373
8 716 115 748 (2009/09)
Supplied By www.heating spares.co Tel. 0161 620 6677
fernox.com
sentinel-solutions.net
12.9 POSSIBLE SOURCES OF CORROSIVE
CFCS
The presence of halogenated hydrocarbons in the
combustion air causes surface corrosion on affected
metals. Particularly susceptible is the combustion
chamber and the heat exchanger surfaces (including
stainless steel) as well as the metal components in the
flue socket, flue pipe connections and in the chimney.
The halogen compounds present in the combustion air
produce highly corrosive hydrochloric acid in the flame
and in some cases - depending on the precise
composition of the combustion air - hydrofluoric acid,
both of which accumulate in the boiler and remain active
over long periods.
In order to limit the damage, the source of the air
contamination must be located and sealed off. If this is not
possible, the combustion air must be drawn from an
alternative clean source.
Halogens can occur in the following locations:
Commercial and industrial sources
Dry cleaners Trichloroethylene,
tetrachloroethylene, fluorinated
hydrocarbons
Degreasing baths Perchloroethylene,
trichloroethylene, methyl
chloroform
Printers Trichloroethylene
Hairdressers Aerosol spray propellants,
hydrocarbons containing fluorine
and chlorine (freons)
Sources in the home
Cleaning and Perchloroethylene, methyl
degreasing agents chloroform, trichloroethylene,
methylene chloride, carbon
tetrachloride, hydrochloric acid
Home workshops
Solvents and Various chlorinated
thinners hydrocarbons
Spray cans Chlorofluorohydrocarbons
(freons)
APPENDIX
79