Draining The Central Heating System - PENSOTTI PCH 50B-H Instruction Manual

6.6 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 hosepipe 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 manual air vent located on the
primary heat exchanger.
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.
If only the boiler needs to be drained, close the flow/return isolating valves on the heating circuit
and open the drain valve R located at the bottom of the boiler on the pump manifold (see fig. 1 );
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 mains water supply valve.
Open all the hot and cold water taps.
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.
Glycol must not be used in Domestic Hot Water applications.
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.
MAINTENANCE INSTRUCTIONS
R
Fig. 1
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