2.5.4 Return lift
If the hot water return is below the minimum return temperature, some of the hot water
outfeed will be mixed in.
CAUTION
Risk of dropping below dew point/condensation formation if operated without
return temperature control.
Condensation water forms an aggressive condensate when combined with
combustion residue, leading to damage to the boiler.
Take the following precautions:
❒ Regulations stipulate the use of a return temperature control.
➥ The minimum return temperature is 65 °C. We recommend fitting some
sort of control device (e.g. thermometer).
2.5.5 Use with storage tank
NOTICE
In principle it is not necessary to use a storage tank for the system to run
smoothly. However, we recommend that you use the system with a storage tank,
as this ensures a continuous supply of fuel in the ideal output range of the boiler.
For the correct dimensions of the storage tank and the line insulation (in accordance
with ÖNORM M 7510 or guideline UZ37) please consult your installer or Froling.
⇨ See "Addresses" [page 60]
2.5.6 Chimney connection/chimney system
EN 303-5 specifies that the entire flue gas system must be designed to prevent,
wherever possible, damage caused by seepage, insufficient feed pressure and
condensation. Please note in this respect that flue gas temperatures lower than 160K
above room temperature can occur in the permitted operating range of the boiler.
NOTICE! Please see the technical data contained in the assembly instructions for
further information about standards and regulations as well as the flue gas
temperatures when clean and the other flue gas values!
Safety
2
Design information
Operating Instructions | B1300015_en
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