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CAHA Midi
Installation, Usage and Maintenance Instructions
6.3.3 WATER-TREATMENT
Before filling up the installation (old and new), the installation should be rinsed thoroughly with clean water from
the tap.There are some rinsing/cleaning products listed below and it is recommended that these are used.
▪
The pH must be kept between 7 and 8,5 at all times
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The maximum allowed content of chlorides is 150 mg/ltr.
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The water hardness of the heating system must be according to the German VDI guideline 2035. See following table:
<0,11 ºdH = demineralised
ºdH =German VDI hardness
Installation
< 20 ltr/kW
Installation
between 20 and 50 ltr/kW
Installation
> 50 ltr/kW
50-300kW total boiler capacity
<11,2 ºdH
<8,4 ºdH
<0,11 ºdH
300-600kW total boiler capacity
<8,4 ºdH
<0,11 ºdH
<0,11 ºdH
>600kW total boiler capacity
<0,11 ºdH
<0,11 ºdH
<0,11 ºdH
▪
Example: for a CAHA Midi 340kW boiler and a total hardness of 8,40 ºdH (German VDI hardness) the total volume of
filled, refilled and topped up water must not exceed 20 ltrs/kW. If this hardness value is exceeded the total amount of
filling, refilling and topping up water is (8,4 / actual hardness in ºdH) x ltrs/kW. In the case of water hardness of 15ºdH
the maximum volume/kW is: (8,4/15) x 20 = 11,2 ltr/kW. If higher values are present, the water should be softened.
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The water may only be partly softened to a value of 20% of its original value. Example : if the initial hardness is 15°D,
then it may only be softened to 3,0 ºD Note that water softening by means of ion exchange principle is not allowed. If
the installation is filled with demineralised or distilled water additives must be added to stabilise the pH value in order to
prevent corrosion. Before filling with demineralised water the complete installation must be rinsed.
▪
The conductivity of the non treated installation water must not exceed the value of 300 μs/cm in combination with a
max O
2
content of 0,1 mg/ltr. If the O
2
content is lower than 0,02 mg/ltr a higher conductivity limit of 600 μs/cm is
allowed. if the conductivity is higher than the values mentioned above, empty the system, flush and fill with clean tap
water, prefeably by adding the recommended cleaning products.
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The water pressure must be higher than 0,8 bar
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The water quality must be checked on a regular basis (at least annually)
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There are many products available on the market which pretend to clean and protect heating systems. Unfortunately
there are only a few that have really proven this in practice.Therefore RVR Energy Technology only allows the following
quality products for water treatment ;
Producer : Fernox www.fernox.com
- Cleaner F3 : removes corrosion, lime and sludge
- Protector F1 : protects against corrosion, lime and sludge
- Alphi-11 : anti-freeze and protection against corrosion and lime
Producer : Sentinel www.sentinelprotects.com
- X100 : Inhibitor scale and corrosion protection
- X200 : Noise reducer long life system treatment to eliminate noise
- X300 : System cleaner for new hydronic heating systems
- X400 : System restorer non acid cleaning of older systems
- X500 : Inhibites antifreeze against scale and corrosion in all types of indirect heating systems at low temperatures
Note that these products must be used strictly in accordance with the water treatment manufacturers instructions.
Furthermore we strongly recommend the following ;
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Use the above mentioned water treatment protection products to fill and protect the installation
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Use a log book to record water filling, refilling, topping up, water quality measurements and water treatment
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Only use diffusion tight material, especially for under floor heating
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Always mount air vents at the highest points in the installation.
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Install isolation/check valves near the boiler and on strategic locations (anticipating any future expansions of the sys-
tem) to avoid fills, refills and topping up as much as possible.
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Install a water meter to check the amount of filled, refilled and topped up water.
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Install a filter (magnetic and dirt) in the return.
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Install an isolation heat-exchanger to separate the boiler from the installation to protect dirt or lime in the secondary
system from affecting the boiler.
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Avoid leaks and if there is a leak, repair as soon as possible.