Table of Contents
Advertisement
Manual de-airing the heat exchanger
The heat exchanger of the boiler can be manually de-aired by means of the air-vent of the boiler. This air vent is
situated at the top left of the boiler.
Open
Closed
position
position
Figure 7.16
With the air also a small amount of water can stream out; with attached drain hose the drained
water can be easily collected Take care the drain tube is outside the boiler so components
and burner controller inside the boiler will not become wet.
NOTICE
Automatic Feed Valve
If an automatic feed valve is installed in the system, it must not be left open indefinitely. A continuous feed of fresh
water could damage the system (fresh water brings fresh oxygen into the system). It is recommended that, after a
short period of time following the installation of the boiler into a heating system, the automatic feed valve is closed.
When using an automatic water refill system some precautions must be taken, like installing a water meter to
measure and evaluate the total water volume added to the system. A water meter can be used to detect and
eliminate any water leakage as soon as possible.
When an automatic feed valve system is used, some form of monitoring must take place to prevent continuously
filling of the system with large amounts of oxygenated fresh water. This can occur when a leak in the system is not
detected and the total water amount added is not being monitored.
Water pressure
The installation must be designed and built conformably to all applicable regulations and standards, including the
right safety relief valves.
IMPORTANT: Always keep the pressure in the boiler lower than the value at which its safety relief valve opens.
Sensor
A water pressure sensor has been built into the boiler. The minimum water pressure in the boiler is 11.6 psi and
the maximum pressure is 43.5 psi. The normal water pressure must be between 18 and 28 psi. The pressure
sensor will stop the boiler from firing when the water pressure drops below 11.6 psi, and starts the boiler firing
again when the water pressure reaches above 14.5 psi.
These values should never be changed in the boiler control settings. The boiler cannot be properly purged of air if
the water pressure is less than 14.5 psi.
Higher pressure systems (e.g. in high buildings)
If a pressure higher than 43.5 psi is required for the heating system, the best solution is to separate the system
from the boiler by means of a plate heat exchanger. In this way, the boiler pressure can remain under 43.5 psi.
44
E93.1901EN032 Installation and Service Manual SlantFin VGH-CH / CO
To manually de-air the heat exchanger:
• Use a plastic pvc tube with an inside/
outside diameter of 0.27/0.39 inch. Only
deaerate when the water and heat exchanger
are cold.
• put a fitting with a tube to the air vent;
• slowly turn the vent open until the air
escapes;
• The screwing and unscrewing of the air
vent must be done manually only. Using a
wrench or pliers is prohibited (to avoid
applying a torque above the one to be
manually applied)
• A high torque caused by using a wrench
or pliers could damage the functioning or
the tightness of the manual air vent.
• when all the air is removed, close the air-
vent and remove the tube.
Advertisement
Table of Contents
