Corrosion Protection; Requirements For Heating Circuit Water - Potterton EC three 125 Installation, Operation And Maintenance Manual

Before installation

4.2 Corrosion protection

4.3 Requirements for heating
circuit water
18
Caution! Risk of damage of the device!
The combustion air must be free from corrosive elements - especially fluorine and
chlorine containing vapours which are found, for example, in solvents and clean-
ing agents, propellant gases etc.
When connecting heat generators to under-floor heating systems, employing plas-
tic pipe work which is not impervious to oxygen in accordance to DIN 4726, heat
exchangers must be used for separation purposes.
Note: Avoidance of damage in hot water heating systems due to corrosion from
water.
If the pH-values of the system water during operation are outside of the limit val-
ues according to VDI guideline 2035-2 a treatment of the fill water for corrosion is
required. For under-floor heating systems and piping with is not impervious to
oxygen, a system separtion between the boiler and other system components at
risk of corrosion must be used.
To ensure economical operation and to keep the heat exchanger in serviceable
condition it may be necessary to treat the filling water with additives. If the water
hardness is greater than 17.5 degrees Clarke or 259mg/litre of Calcium then, this
must be treated. The treatment depends on the total water hardness, system vol-
ume and the size of the boiler.
If, in a special case, a need exists to use additives in a mixture (e.g. hardness sta-
bilser, frost protecion agent, sealing agent,etc.) it has to be observed that the
agents are compatible with each other and the pH-value is not altered. Preferably,
agents from the same manufacturer should be used.
The instructions of the additive manufacturer must be observed.
Released additives
Currently, the following agents have been approved by Potterton Commercial:
- "Full heating protection" from Fernox
- "Sentinel 100" from GE Betz
As a single frost protection agent, also Tyfocor® L may be used.
If not approved agents are used, the guarantee becomes void!
When softener facilities are used, water softening to a hardness of minimum 6 to
8 °dH is recommended.
The pH-value must not exceed the permissable value of 8.3.
Maintenance instructions
The water hardness of the heating water has to be checked within the scope of the
recommended maintenance of the boiler (every two years) and, possibly, the re-
spective amount of additive has to be added.
Condensing gas boiler Eurocondense three125-300 kW 7308536-02 06.13