PENSOTTI PNCC-32N, Instruction Manual

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MAINTENANCE INSTRUCTIONS
67
6.5 Draining the central heating system
If the need arises to drain the system, this can be done
as follows:

Switch the system to “HEAT” mode and ignite the
boiler.

Switch off the power supply to the boiler.

Wait for the appliance to cool down.

Connect a hose to the system drain point R and
locate the other end of the hose in a suitable
drainage system.

Open the system drain valve (fig. 1).

Open the air vents on the radiators, starting with the
highest and moving down the system to the lowest.

When the system has been drained, close the
radiator air vents and the drain valve.
Draining the domestic hot water system
If there is a danger of freezing, the domestic hot water system should be drained. This can be done as follows:

Close the main water supply valve.

Open all the hot and cold water taps.

Drain the water from the system. Used compressed air to evacuate the pipes of any remaining water.

Use non-toxic antifreeze to protect the DHW system.

On completion, close all the previously opened taps.
Freeze Protection
Glycol must not be used in Domestic Hot Water applications.
System winterization (non-operative system)
Because it may be impossible to completely drain the boilers heating circuit, D.H.W circuit and distribution system.
Pensotti recommends the introduction of the proper type antifreeze to protect these systems from freezing damage.
System winterization (operating system)
Pensotti boilers are certified for indoor use ONLY. Proper precautions for freeze protection are
recommended for boilers and associated piping in areas where the danger of freezing exists. Do not use
automotive antifreeze. Pensotti recommends the use of inhibited glycol concentrations between 20-35%
glycol. Glycol products must be maintained properly so they do not become inactive or corrosive, consult
glycol specifications for more information.
Fig. 1