Water Quality; Use Of Glycol - Slant/Fin VGH-299-CH Installation And Service Manual

Water quality

Maximum allowable
Contaminant level
pH 7.5 to 9.5
Hardness 50 to 150
2.92 to 8.76
Aluminum particles < 0.2
Chlorides 150
TDS 350
Table 7. 2
It is advised to prevent the possible air intake and water leakage of the central heating system. Fresh oxygenated
water might damage the heat exchanger of the boiler and must therefore be prevented! Usual spots where air is
most likely to seep in are: suction gaskets, circulators, air valve working as a venting pipe, O-rings / gaskets in
stuffing box, under floor heating pipes.
When a boiler is installed in a new system or an existing installation the system must be cleaned before the boiler
is installed. The system is required to be cleaned using a system cleaner from the list below or an equivalent
hydronic system cleaner. Follow the instructions provided by the system cleaner manufacturer. The system must
then be drained and thoroughly flushed with clean water to remove any residual cleaner. The system cleaner
must Never be run through the boiler. For recommended cleaners see table 7.4
Do not use petroleum-based cleaning and sealing compounds in the boilers system as they could damage
gaskets. When using antifreeze in the system always use an inhibited mono propylene glycol antifreeze approved
for use in heating systems. Never use Ethylene glycol in a heating system as it is toxic and can damage gaskets.
Read the antifreeze suppliers manual for the maximum allowable level of antifreeze that can be used with the
boiler.
The pH and water quality of the system must be checked on a yearly basis when antifreeze is used in a system.
Replace the antifreeze every 5 years or sooner based on the instructions from the manufacturer or if the pH is out
of the required range.
A micro bubble air elimination device is required to be installed in all heating systems. An air scoop is not an
acceptable substitute for a micro bubble air elimination device and may not be used in the installation. A few
examples of acceptable devices are
*Spirovent
*Taco 4900 Series
*Caleffi Discal
If an automatic feed valve is installed in the system, it may not be left open indefinitely. A continuous feed of fresh
water could damage the system. It is recommended that after a short period of time following the installation of
the boiler into a heating system that the automatic feed valve be closed.
If the boiler is used in a system with snow melt where antifreeze percentages are above the suppliers specified
values, it must be isolated from the snow melt with a plate heat exchanger.

Use of glycol

To prevent the system from freezing,
resistant to glycol.
Glycol at itself will acidify because of thermal degradation over time. This acidity will cause serious damage to
most components in the heating system including the boiler. Because of this, specific anti-freeze products are
available in the market for use in heating systems. These consist mainly of glycol, but they have additives added
which act against internal corrosion and/or scale formation. An important part of these additives are so called
"balancers" which are added to the product, to absorb the rise of acidity of the glycol over time because of thermal
degradation.
The chemical compatibility of two specific anti-freeze products has been tested by the heat exchanger producer.
These products mainly consist of glycol next to the described additives.
If these products are used according to the instruction, they will not harm the boiler.
24
Units
mg/l CaCo3
Grains/gallon
mg/L
Ppm
Ppm
the use of glycol can be considered. All materials, used in the boiler, are
E93.1601EN032.C VGH installation manual
The pH value is reached with the steady
conditions. These steady conditions will occur,
when after filling the heating system (pH around
7) with fresh water, the water will lose its air
because of the air bleeding operation and
heating up (dead water conditions).
If there is the risk of contamination of the water
by any kind of debris/chemicals in the period
after installing, a plate heat exchanger must be
used to separate the boiler circuit from the
heating circuit (see drawing at the next page).