Potterton eurocondense four 125 kw, Installation, Operation And Maintanance Manual, Page: 27 / 148

Caution
Keep the installation room frost-free.
If an antifreeze agent is used, pipework, radiators and gas con­
densing boilers are protected against frost damage. For the gas
condensing boiler to be ready for operation at any time, suitable
measures must also be taken to keep the installation room frost-
free. If applicable, please also note special measures for any in­
stalled domestic hot water calorifiers.
The table shows the relevant amounts of heat transfer medium and water
that need to be mixed together for varying volumes of water. If other frost
protection temperatures are required in exceptional cases, individual cal­
culations can be made on the basis of this table.
Water content of
the system
[l]
Amount
Lasacor® LS 1
[l]
Water in the mix­
ture
(1)
[l]
Frost protec­
tion down to
[°C]
50 36 14 -15
100 71 29 -15
150 107 43 -15
200 143 57 -15
250 178 72 -15
300 214 86 -15
500 357 143 -15
1000 714 286 -15
(1) The water for the mixture must be neutral (potable water quality with no
more than 100 mg/kg chlorine) or demineralised. Please also follow the
manufacturer instructions.
5.2.7 Water hardness tips
1. With reference to the specific system volume (e.g. when using heating
water buffer storage tanks), determine which requirements apply re­
garding total hardness of the fill and top-up water to VDI directive
2035 and the following table.
If partial softening to 6°dH is insufficient according to the project-spe­
cific water hardness diagram, use either an additive or use only fully
desalinated water (with pH stabiliser).
If a boiler is replaced in an existing system, we recommend installing a
dirt trap or filter in the system return, upstream of the boiler. Flush the
system thoroughly.
2. Depending on the materials used, determine whether the addition of
inhibitors, partial softening or full desalination is the best method.
3. Record the filling process (If an additive is used, note this on the boil­
er). To prevent gas pockets and bubbles, it is essential to fully vent
the system at maximum operating temperature.
4. After 8 to 12 weeks, check and record the pH value. Offer and con­
clude a maintenance contract.
5. Once a year, check the system is operating correctly with regard to
pressure maintenance, pH value and the volume of top-up water
used.
Tab.6 Table to VDI 2035 Sheet 1
Total heating output
in kW
Total hardness in °dH
subject to the specific system volume
< 20 l/kW ≥ 20 l/kW and
< 50l/kW
≥ 50 l/kW
< 50
(1)
≤ 16.8 ≤ 11.2 < 0.11
50 - 200 ≤ 11.2 ≤ 8.4 < 0.11
200 - 600 ≤ 8.4 ≤ 0.11 < 0.11
5 Before installation
7636047 - 02 - 24082015 27