Checking Heating System Operating Pressure; Testing Relief Valve - Buderus Logano G115/3 WS Installation And Service Instructions Manual

8.4

Checking heating system operating pressure

The system pressure for closed systems must be
15 – 30 psi (1.0 – 2.1 bar).
▶ Check system pressure.
▶ If the pressure gauge shows less than 15 psi, the pressure is too low.
Top up the system with water.
CAUTION: Risk of system damage due to frequent
topping up.
If you have to top up the heating water frequently, the
heating system may suffer damage from corrosion or
scaling, depending on the water quality.
▶ Ensure that your heating system is bled properly.
▶ Check the heating system for leaks and proper
operation of the expansion vessel.
Fig. 40 Pressure/temperature gauge for showing operating pressure
and feed temperature
CAUTION: Risk of damage to system due to material
stresses caused by temperature differentials.
▶ Only fill the system when cold (the flow temperature
at the temperature/pressure gauge should be no
more than 100 °F).
▶ Add water through the feed valve.
▶ Bleed the heating system.
▶ Check the operating pressure again.
8.5

Testing relief valve

The functioning of the pressure relief valve must be checked at regular
intervals (1-3 years as specified by local codes).
▶ Make sure that no persons are in the discharge area of the pressure
relief valve.
▶ Raise the lever on the pressure relief valve.
The pressure relief valve must open and release pressure. If the pressure
relief valve does not discharge, it must be replaced, because system
components may be damaged by excessive pressure.
Logano G115 WS US/CA – 6 720 813 418 (2019/09)
7 747 019 141-17.1RS
Heating system servicing
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