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5.5. Warning on water level in system
After first water make-up in the system, minimum water level must be marked on hydrometer for open
vented circuits, minimum water pressure level must be marked on manometer for pressurized circuits.
Water level or pressure should be checked daily, and water should added to circuit if they are below the
minimum value. During first water make-up, oxygen must be fully discharged from the system. Generally,
oxidation will not be a problem, if all measures are taken into account during first water make-up. Oxidation
will take place because of fresh water addition to the system during operation of the boiler. The main
reasons are as follows:
1. In open vented systems, oxygen will be added as expansion tank is open to atmosphere. That is why,
open expansion tank sizes, its position in the system, safety connections to and from, are very important,
and instructions given in this manual for open vented systems should be followed carefully.
2. Leak points in a system will cause oxygen to be absorbed inside the heating water. For this reason,
minimum water pressure in a pressurized heating circuit must be above atmospheric pressure. Besides,
pressure level should always be checked periodically.
5.6. Precautions for new installations:
System should be sized and designed accordingly, in order to minimize fresh water addition. Make sure that
no part of the system is made of material that is permeable to gases. The original system filling water and
any topping-up water must always be filtered (using synthetic or metal mesh filters with a filtration rating of
no less than 50 microns) to prevent sludge from forming and triggering deposit induced corrosion.
5.7. Chimney connection
Your boiler must be connected to an individual chimney that will provide at least the minimum draught
requested. The flue canal between the boiler and the chimney should be insulated using a glass wool
material. The flue canal to chimney and chimney must be made of steel or an equivalent material that can
be used at temperatures around 400
o
C.
All connections on flue system must be sealed in order to perform a good combustion and efficiency. The
flue canal must be connected to the chimney using the shortest way possible and in accordance with the
dimensions given in the following scheme. Horizontal connections and equipments that will increase the
pressure loss such as elbows should be avoided
A vertical single steel piping should not be used as a chimney. Chimney must be made of one internal and
one external surface. External surface may be made of steel or brick. For internal surface stainless steel
chimney elements should be preferred against corrosion. The space between internal and external surfaces
of the chimney should be insulated to prevent condensation in flue gasses.
At the lowest level of chimney, there should be a cleaning cover which is made of steel, and sealed for any
leakage. The length of flue canal between the boiler and the chimney should not exceed ¼ height of
chimney.
