8
Heating system servicing
Logano G115 WS US/CA – 6 720 813 418 (2019/09)
37
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.
Fig. 40 Pressure/temperature gauge for showing operating pressure
and feed temperature
▶ 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.
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.
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).
7 747 019 141-17.1RS
