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Technical Manual

Thermo Siphon System

Solar Energy

This manual is for exclusive use of Bosch installers and technicians of the

authorized service partners.

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1) Introduction

Solar thermal systems collect heat from the sun for heating water, for different purposes,

as for central heating, swimming pool heating, or domestic hot water consumption.

The aim of this manual is to give guidelines and best practices recommendations on

domestic hot water use, to Bosch Service Partners and Installers, on Solar Thermo

Siphon Systems for – DHW – Domestic Hot Water production for sanitary purposes.

The manual gives also an overview of the main changes on the actual TSS System from

Bosch, in order to comply with some of the main request given during 2nd generation of

product.

1.1) General Variants of Thermo Siphon Systems

Pict.1 – Direct system representation (source Caleffi)

Pict.2 – Indirect system representation (source Caleffi)

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1.2) Thermo siphon working principle

One of the most common system designs is the thermo siphon system. It is perhaps the

most widely used system design in the world. It is based on the natural convection to

collect the heat from the sun and store it in an insulated tank for later end user need. The

sun rays are absorbed by the collector absorber, which heats the fluid inside the collector

tubes. When the fluid is heated inside the collector tubes, its density decreases and,

naturally, the fluid goes up and enters inside the tank, which is on the top of the collector.

After transferring its energy, the cooler fluid from the tank drops down into the bottom of

the collector and the cycle continues, as long as the sun is able to heat the fluid in the

collector.

Insulation in the back and sides of the collector and the glazing in the front of the collector

allow it to collect heat during the day, at much higher temperatures than the surrounding

ambient air. The insulated tank reduces heat losses, so the heated water can be stored

for long periods of time until it is consumed. The roof structure must be able to support

the whole system weight or, an alternative installation area must be considered.

In order to ensure a natural convection effect to work in a thermo siphon system, the

storage tank must always be installed at a level above the top header of the collector.

Pict.3 – Example of solar thermo siphon system

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2) Installers Brief

The largest market for solar thermal installers has traditionally been in retrofit situations.

In retrofit settings, the installer takes whatever conditions they find and makes things

work.

During the construction of new residences, the emphasis should be on systems

integration, optimal design, and interaction with other trades. Nevertheless, best practices

and good conduct will help the installers in new contracts and installations’, leaving a

good image of the Brand and it’s after sales organization.

• Use specialized knowledge to educate constructors. New construction provides an

opportunity to optimize the equipment and installation process;

• Work with site supervisors, roofers, plumbers, and other specialists, to determine

the best installation sequence and schedule what materials should be provided, in

order to optimize working sequence and to avoid unnecessary work, roof

penetrations, etc;

• Confirm solar exposure before mounting any equipment on the roof, to avoid

shadows from vents, trees and/or buildings;

• Provide quality assurance inspections and maintenance contracts with end users;

• Select packages that preserve floor space and maintain a tidy appearance;

• Use quality assurance techniques to avoid problems;

• Work with the constructor to develop inspection protocols;

• Correct any installation problems immediately, in order to ensure a good image

and sense of respect and professionalism from the brand, to the end user;

• Protect pipe circuit from other trades that may also need access to the same

spaces or that may need to create circuits of their own;

• Label and fix pipe circuits, so that they are not pushed up and out of the way,

creating water traps and freeze hazards.

It may be necessary to ensure having teams to do pre-installations, collector installations,

and interior component installations. Different teams may do these tasks simultaneously,

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or one team may have different jobs at different times. Be clear with the site supervisor

about demands for teams intervention time.

Work with site supervisors, roofers, plumbers, and others to determine the best time to

schedule and what materials to provide. Pay attention to other trades that will be working

in the same space.

For the operations of pre-installation check, installation or maintenance, take care always

of the necessary devices and tools for safety assurance. Workers must be protected from

difficulties or obstacles in the field, in order to avoid accidents.

A safety check-list is recommended in order to ensure, before the beginning of work

activities, that all the necessary equipment of protection and installation are available.

2.1) Identification of risks during works on the roof by service partner or installer

– Installation of heavy objects;

– Execution of works on the roof or higher positions;

– Protection of fragile materials;

– Presence of plumbing pipes (gas or others fluids);

– Proximity to high voltage wires or other electrical cables;

– Atmospheric conditions (wind speed, rain, etc);

Pict.4 – Identification of risk areas in installation and servicing of TSS systems

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2.2) Identification of the equipment and safety material needed

a) Equipments for collective protection

- Railings

- The scaffolds (fixed or not)

- Fixed stairs

- Motorized elevation platform

- Motorized platform to elevate material without damages;

Pict.5 – Example of collective protections (scaffolds and stairs)

Pict.6 – Example of elevation platforms for material / persons

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b) Equipment for individual protection

- Helmet

- Safety Shoes

- Protective gloves

- Harnesses

- Safety glasses

- Hearing Protectors

Pict.7 – Example of individual protections

c) Complementary equipments of protection

- Stop losses

- Locking Solo

- Pole attachment

- Temporary Lifeline

- Anchor Point Roof

- Belt Tools

Pict.8 – Example of complementary safety tools

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Attention:

The installer is responsible to install the equipments properly, the do the connection and

interface with existent backup heating appliances and / or accessories and the start up of

the system, ensuring correct and proper working.

The technician is responsible for check Installation system, repair and inform end user of

an eventual correction need by the Installer, ensuring safety and a proper operation of the

system supplied by Bosch.

At the end of the installation activities, the system documentation should be given and

explained to the end user and a maintenance contract should be done in order to prevent

any system problems.

3) General Concepts

On a clear day, solar radiation is most intense at solar noon (e.g., that time of day when

the sun reaches its highest position in the sky and directly above a polar north/south line).

Before striking the earth’s atmosphere, solar radiation travels in straight paths. This is

called the “direct” solar radiation. On a clear day, the majority of solar radiation striking

the earth’s surface is direct radiation and, because of travelling in straight lines, direct

radiation is easy to reflect.

If there was no atmosphere, nearly all the solar radiation that would reach the earth

surface would be direct radiation, however, the gas and vapour molecules in the

atmosphere create a very different scenario. They reflect a significant portion of the

incoming direct radiation in every direction. The result is called “diffuse” solar radiation. Its

presence is the reason why we see the sky and objects around us in a very different way

as they could be seen in space, without atmosphere.

The majority of solar radiation reaching the earth surface on cloudy days is diffuse

radiation and this one cannot be easily focused.

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Pict.9 – Overview of solar energy incidence in Europe

3.1) Solar Orientation

The orientation of the solar collectors should be always facing sun position and trajectory

according to the solar diagram of its localization.

We have so:

- North hemisphere – orientation facing South

- South hemisphere – orientation facing North

Pict.10 – Example of orientation and solar trajectory (source Caleffi)

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However, and in order to adapt to a real situation or to avoid sun obstacles, short

deviations to east or west are acceptable without a big decreasing of system efficiency,

with a maximum recommended deviation of ± 20º.

Deviation until - 20º East Deviation until + 20º West

Pict.11 – Collector orientation to South in North Hemisphere

Deviation until - 20º East Deviation until + 20º West

Pict.12 – Collector orientation to North in South Hemisphere

3.2) Collector Inclination

The solar collector angle is usually the correspondent one with the latitude of the

installation place, nevertheless, in the thermo siphon system in flat roof, the angle is fixed

and in the on roof installation, generally is used the roof tilting to support system.

As a general rule, the following consideration can be taken in consideration:

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Thermo siphon system with flat roof support system:

- Fixed angle of the support structure

Thermo siphon system on roof:

1. Inclination = Latitude of location – 15º

Note: This situation is better to improve Domestic Hot Water (DHW) production in

summer;

2. Inclination = Place latitude – 5º

Note: This situation is better to have in a installation working during whole year

(ideal for TSS);

3. Inclination = Latitude of location + 15º

Note: This situation is better to improve DHW production in winter

Pict.13 – Example of different collector inclinations

Pict.14 – Collector inclination adaptation

3 2 1

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3.3) Shadows

The existence of buildings, trees or other obstacles in front of a solar system can be a

problem and reduce the system efficiency, decreasing the number of sun exposition

hours to the available solar energy.

These situations must be verified before installation with the correspondent solar diagram

of the location, and communicated to the end user, in order to know the consequences of

a solar fraction reduction.

Solution can be the increase of the solar area exposition or the adaptation of an adequate

backup solution.

Pict.15 – Example of obstacle to a solar system for latitude N 40º

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Pict.16 – Example of solar diagram for a location at latitude of 40º N

Pict.17 – Example of a solar diagram for 40 N latitude and obstacle influence indication

Also the obstacles in the installation place should be considered, for example in case of

walls or other systems that might provoke shadows on the collector.

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Pict.18 – Example of formula to calculate distance between rows of solar systems

Pict.19 – Example of simplified formula to calculate distance until the nearest wall

4) Solar System

Solar water heaters differ from conventional water heaters in two fundamental

characteristics. The first and most obvious is that, most of the primary energy used to

heat the water is provided free by the environment in which the heater is placed. The

second difference is that the input to this primary source of energy varies from season to

season. Often, the annual variation ranges from low levels of solar energy at times of

higher need to excessive level for times of less energy need.

Not only does the primary energy source vary with the seasons, but it often varies widely

from day to day. If this free energy component is to be maximised under these

circumstances, the storage capacity and insulation properties of a solar water heater

need to be greater than those of a conventional hot water system. This way, it is possible

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to accumulate some residual energy from a previous good day to one for which the solar

input may be not sufficient.

Solar hot water systems also require auxiliary energy supplies. These are usually

provided by a heating element as an electric resistance immerged in the water, or using

an instantaneous gas water heater installed in series with the solar system.

To ensure that an auxiliary element does not waste energy on heating water more than

required, the element is located in the centre of the vessel. In this way, the element heats

only the upper part of the stored water, however and as we are talking about big storage

tanks, it’s recommended the use of a backup appliances of instantaneous gas water

heaters with adequate accessories, in order to heat only when hot water consumption is

needed, avoiding extra heating consumption of electricity, when there is no tapping and

with a possible re-heating by the free energy of the sun.

Pict.20 – Cut view of Bosch solar tank

4.1 – Storage Tank – enamelled vitreous

The internal surface of the vessel is treated with a coat of enamelled vitreous. This

treatment is applied to protect the steel surface of the vessel against corrosion attack

and, is considered to be one of the the best corrosion protection methods for steel

vessels, from the point of view of hygienic purposes for domestic hot water applications

and durability.

The reasons are the following:

- resistance to corrosion.

- resistance to permanent scale deposition

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- resistance to high temperatures.

The enamel comprises a mixture of silica and clays that, when fused, has a coefficient of

expansion comparable to the one of the steel. The vessel and clay mixture are heated till

860°C and the resultant enamel melts and fuses covering the steel surface. When

cooling, the steel vessel contracts at a slightly greater rate than the enamel and it’s

therefore, under a slight compressive stress at low temperature. (Glass is extremely

strong in compressive strength).

In normal operation, the vessel can be heated up to 99°C and will therefore tend to

relieve only some of the pre-stressed compression.

In practice, large and sudden temperature variations between the enamel lining and the

vessel wall do not occur.

Pict.21 – Internal view of the vessel tank

Water has considerable thermal inertia, (time required for a temperature change with

application or withdrawal of heat). The intimate bond of the enamel with the vessel

prevents temperature gradients between the glass lining and the steel body.

The enamelling process is essential for the long life under the high temperature

conditions that might occur on solar hot water systems, even with large collector areas

and higher performance collectors.

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4.2) Magnesium anode and corrosion protection

The storage tank is fitted with a replaceable magnesium anode. The use of an anode in

corrosion protection is known as a cathode protection system.

The anode is protects all non covered enamel lining areas.

Pict.22 – Anode and its accessibility

The time life of the anode depends on different factors such as:

- type of anode (material);

- type of water (conductivity and pH);

- temperature of the water.

Essentially the life of the anode is determined by its natural solubility in the water where it

is immerged. For this reason, the life of the anode is quite variable.

Due to the time life variation, we strongly recommend a yearly inspection and than, the

replacement according to the results from the firs inspection: Note: the replacement of the

anode is much less expensive than replacing the vessel.

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Attention: In areas with bad water quality, the anode may need to be changed very

frequently.

Pict.23 – example of different corrosion level of the anodes

Corrosion is a chemical reaction that takes place on the surface of a metal. The worse

common reaction in the rusting of iron is the reaction with water and dissolved oxygen.

The severity of the corrosion attack from fresh water on metal varies widely, depending

on the dissolved salts and gases in the water. The principal corrosive agents are

chlorides, sulphur compounds, iron compounds and calcium salts.

The enamelling protection has advantages when compared with stainless steel, because

is not totally stainless and is susceptible to various insidious forms of corrosion such as

stress and crevice corrosion. This is particularly prevalent when, in the presence of high

temperatures, the metal is subject to high operational stress and high chlorides.

Corrosion occurs by a number of mechanisms, however in the case of water heater

cylinders they are mainly:

- Pit and Crevice Corrosion

- Stress Corrosion

- Corrosion Fatigue.

- Galvanic Corrosion

Water hardness is defined by the concentration of calcium ions (Ca++) and magnesium

(Mg ++) responsible by the deposition of calcaire in the interior of pipes and tanks,

provoking problems as decrease of water flow and / or temperature exchange.

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This hardness is generally indicated in ºF (French degrees).

Water Hardness

= 4 mg/l de Ca++

1°F = 2.4 mg/l de Mg++

= 10 mg/l de CaCO3

The water is :

• Soft when hardness is 0 à 18°F, • Mid-hard when hardness is 18 à 30°F, • Hard when hardness is + de 30°F.

As reference, the following values can be used as indicative for good water for domestic

purposes:

Water Quality

Type of Measurement Limits

pH 6,5 à 9

Conductivity 400 µS/cm à 20°C

Chlorides 0,1 mg/l

Temperature 15°C

Water Hardness 4 à 8°F

4.3) Water stratification

The baffler plate in the inlet of water prevents the mixture of the cold water entering in the

vessel with the hot water already inside the tank. This promotes thermal stratification of

the vessel contents.

The device achieves this through a combination of its shape and inverted outlet slot. The

velocity of the incoming water is dropped and the inertia, dissipated by the device. The

cold inlet water drops from the baffler plate through the inverted outlet slot and lies on the

bottom of the vessel. The temperature of the hot water already in the tank is therefore not

diluted which results on an enhanced hot water delivery capacity of the system.

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The water inlet:

- Effectively removes inertia from water without pressure reduction;

- Allows incoming cold water to be placed in the bottom of the vessel, without

mixing or disturbing the hot water layer;

Pict.24 – Cold water inlet baffler plate

4.4) Storage tank insulation

The vessel is fully encased in pressure injected polyurethane foam with very low thermal

conductivity, when compared for example with fibreglass.

Because we have always some losses, in manual is indicated the thermal dissipation of

the tank and under, extreme conditions, this will ensure a heat dissipation preventing

over-heating of the system.

4.5) Cold water pressure relief valve

The cold water relief valve is the main safeguard for excessive internal tank pressure.

The cold water relief valve is set for 10 bar and the system can also have a pressure and

temperature relief valve on other strategic point in the tank.

The cold water relief valve relieves pressure build up in the vessel arising from the

expansion of water as it is heated.

Under normal circumstances, the cold water relief valve can relieve between 5 and 30

l/day (depending on hot water usage, solar energy availability and booster operation),

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however, this can also be avoided in case of the installation of an optional accessory as a

membrane expansion vessel.

The actual valve keeps same functions (non-return, pressure relief and cut) but was

modified in dimensions and is installed in Horizontal position leaving more space,

especially for installations on roof.

Pict.25 – Cold water pressure relief valve

4.6) Storage tank heat exchanger

The solar energy collected by the solar collectors is transferred to the water in the vessel

over the steel wall of the vessel. The large heat exchange wall area, combined with a low

heat exchange rate, assures that the glazed inside surfaces are not excessively heated.

This minimises the build-up of scaling inside of the vessel.

Solar fluid inside the outlet jacket Sanitary water inside the tank

Pict.26 – Cut section of a heat exchanger (double jacket type)

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4.7) Solar Circuit

The solar fluid available is manufactured to comply with strict health and water authority

regulations under food-grade conditions.

The solution is supplied for direct use and will protect the system against freeze damage

till -14°C. Polypropylene glycol is safe in case of possible ingestion or absorption through

the skin.

The application of the solar fluid will prevent the collector from damages caused by

freeze.

Pict.27 – Glycol used by Bosch is Tyfocor L type

Pict.28 – Solar liquid (Glycol) circuit between collector and heat exchanger

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In order to prevent abnormal temperature and pressure reactions in the closed loop, a

pressure relief valve is installed in the top of the tank as indicated in picture 28. It will be

activated around 2,5 bar, however the solar collector is tested and proved until 6 bar.

Pict.29 – Solar circuit pressure relief valve

In this closed loop, the solar fluid is in normal circulation due to the density difference,

however, after some time, the fluid can degrade, depending on some conditions as

excessively sun exposition or long periods of stagnation temperatures.

In order to prevent degradation of solar fluid, the technician or installer should use for

maintenance purposes, the following tools:

Bosch WTI part – PH control strips

Bosch WTP part – density level control

Pict.30 – WTI and WTP tools for solar fluid controls

Following image, gives the indication of the correspondent hydraulic connections and

accessories.

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Pict.31 – Solar thermo siphon system connections

1 – Solar storage tank (double jacket type);

2 – Cold water inlet (cold water pressure relief valve connection);

3 – Solar circuit return from heat exchanger to collector;

4 – Cap;

5 – Return pipe;

6 – Way pipe;

7 – Hot water outlet (thermostatic valve installation);

8 – Solar circuit way connection to the heat exchanger;

9 & 10 – Solar circuit pressure relief valve connection and filling connection.

5) Integration on existent installation place

In case of integration of the solar system with existing appliances as backup, the working

conditions must be known, in order to prevent and install the adequate accessories to

avoid water scalding or damages on the appliance.

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Pict. 32 – Solar Installation examples with integration on roof or flat with existent

appliances

For these situations, installer should be informed of the type of appliance, in order to

advice the correct complementary backup solution to install, or the accessory to adapt to

the existent solution.

Nevertheless, backup system must be always considered, as the solar radiation intensity

is always dependent on weather conditions.

Examples of backup solutions:

- Appliance in serial connection with the solar system, in order to start

working when the temperature from solar is not enough. Usually

instantaneous gas water with enough power to assure that the

instantaneous heating is adequate, however and for safety reasons an

adaption accessory might be needed.

- Electric heating element controlled by a thermostat connected with the

water inside of the tank This solution is not so efficient as the previous

one and takes more time to ensure the desired temperature.

The protection of the appliances and / or users from high hot water supply, mainly during

high sun radiation period can be done by different accessories:

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- Solar kit (in combination with mechanical gas water heaters, which

means, non thermostatic);

- Thermostatic mixing valve (in combination with boilers or gas water

heaters with temperature control) ;

Pict.33 – Bosch solar kit adjusted to an outlet temperature of 45ºC

Pict.34 – Example of a thermostatic mixing valve

Cold Water supply

Hot Water supply from solar tank

Mixed hot water at constant consumption

temperature

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Pict.35 – Example of an adjustable selector of mixing valve and

correspondence between position and temperature of outlet hot water

5.1) Backup with gas water heater

The solar kit will prevent the entry of high temperature to the appliance, and deviate the

hot water (> 45ºC) to a second valve (mixing) in order to ensure the desired outlet

temperature of 45ºC. In case of insufficient water temperature from solar, the first valve

deviates the hot water from solar to the gas water heater in order to heat it up and then,

in the second valve (mixing), it ensures the outlet water temperature of 45ºC

Attention: These are only general indications, but before any further use, the

correspondent manual of solar kit must be read.

Advantages:

� avoid damages on the appliance due to high temperatures;

� avoid scalding of end user;

� avoids the use of a thermostatic gas water heater;

� the backup appliance will only operate when the hot water temperature from solar

is less than 45ºC;

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� less water heater maintenance costs, due to less working periods.

Pict.36 – Example of an installation scheme of thermo siphon with gas water heater

Pict.37 – Working principle when water from solar is higher than 45º

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Pict.38 – Working principle when water from solar is lower than 45º

5.2) Backup with boiler

In case of combination of solar system with temperature control appliances as wall hang

boiler, a thermostatic mixing valve must be assembled in the outlet of the system for

prevention of high hot water temperatures

Pict.39 – Installation scheme of thermo siphon with wall hang boiler

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5.3) Backup with electric heating element

In some cases, where instantaneous gas appliances can not be used, the direct heating

through an electric resistance is possible with an available accessory as indicated in

picture 39.

The working principle is similar to the one of a normal electric storage tank that, when the

thermostat control detects a need of heating, the heating element is electrically

connected and starts warming the water inside the tank. At the same time, the

temperature control thermostat is a safety element acting as a temperature limiter.

Pict.40 – Electric resistance and detail of temperature adjustment in thermostat

ATTENTION:

- Read the resistance installation manual 6 720 680 229

- The correspondence between electric power and water volume must be

10 W/l (e.g.: don’t install a resistance of 3000 W in a tank of 200 l, it

should have a maximum of 2000W)

- The cable area must be 2,5 mm2

Pict.41 – Installation scheme of a system with electric resistance and thermostatic valve

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6) Solar system maintenance

It is strongly recommended a dedicated and specialized maintenance program in order to

ensure the time life of the system and avoid consequences to the end user. As good

practice, Bosch recommends the Installer to make a visit within 6 or 12 months after the

start up of the system and help the end user on establishing a maintenance program

contract with the official Bosch after sales partner.

Technician and / or Installer should advice the end user about the importance of having

the solar collector glass clean (when system is accessible to end user), and contact him

immediately, in case of detecting any type of leakage in the system.

The table 1 shall be consider as a guideline with the most important points to be checked

and with a safe recommendation of inspection time; however, it will be acceptable by

Bosch the adaptation of this tasks by specialized technicians, after sales or installers

according to their own field experience with similar products.

Component Type of

intervention

Frequency

(months) Comments

Collector Inspection 12

Visual inspection to detect internal condensation and other defects.

In case of condenses, clean air vent holes in the collector and check

sealing joint by all surface and structure.

Collector -

glass Cleaning 12

Ensure Cleaning of the glass and in case of need use water and

soap to clean superficial dirtiness. Make this operation in a time

Schedule where sun is not too Strong (morning or end of the day).

Collector -

absorber Inspection 12

Check for corrosion or deformation in the black chrome copper

surface. In case of damaged absorber, replace collector.

Structure Inspection 24 Check all parts and its fixation and avoid corrosion formation in the

fixing elements. Check if screws are tightened.

12

Check the existence of leakages in the inlet and outlet of domestic

water and in case of need replace gaskets or other sealing material

used. Sanitary

water pipes Inspection

24 In case of existence of insulation, check its good status in all pipe

way.

Solar circuit

pipes Inspection 12

Check the existence of leakages in the tank and collector

connections. Replace pipes in case of damaged pipes, restricted or

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blocked and use always new fixation clips.

Test 12

Check by manual activation, the correct working of the pressure

relief valve avoiding the blocking of the safety device due to no

activation. Storage Tank

Inspection 12

Open visit trap and check insulation and presence of calc or

sediments inside of the tank. In case of need, clean internal tank of

sediments deposition with a vacuum cleaner.

Solar Fluid Test 12 Check density and PH of solar liquid with appropriate device (see

table 3)

Magnesium

anode Inspection 12 Check visually the status of the magnesium anode (see table 2)

Table 1 – Suggestion of a maintenance program

6.1) Structure control

The new TSS 3rd generation has include some changes in the aluminum structure in

order to reduce complexity, but keeping the same robustness.

The following key points should be checked during maintenance in order to be sure that

system is correctly attached to roof supports.

Pict.42 – Structure of a thermo siphon and important fixing points (TSS 3rd Generation)

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6.2) Magnesium anode control

The criteria for the control of the magnesium anode is checking its visual aspect and

when possible, checking its diameter, weight and dimension. In order to help service, the

following table gives an indication of the minimum values to be considered.

Model Weight

(Initial)

Weight

(minimum)

Diameter

(Initial)

Diameter

(minimum)

Length

(Initial)

Length

(minimum)

TSS 150 422 g 280 g 20 mm 13 mm 600 mm 400 mm

TSS 200 422 g 280 g 20 mm 13 mm 600 mm 400 mm

TSS 300 531 g 354 g 25 mm 16 mm 1120 mm 740 mm

Table 2 – Minimum control values for the magnesium anode

Pict.43 – Corroded anode in a tank

6.3) Solar liquid control

Before filling the solar fluid in the system, ensure that the “Glycol” of direct use, is well

mixed in the supplied recipient and before use, shake the vessel to ensure good mix.

Attention: Solar collectors must be cold before and during filling process for the system.

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Pict.44 – Cover the collector to fill with solar fluid, keeping it cold

Pict.45 – PH control with WTI and density control with WTP device

The following table, give to the service man the indication of the recommended values of

the two parameters of the solar fluid.

Inspection Frequency Value Maximum value

(limit) Comments

PH control PH between

7 and 9

Replace if PH < 5

or > 9 (acid or

basic fluid)

Density

control

Every year

Protection

until -14 ºC

Replace if value is

> -5 ºC

Even with

acceptable

values, replace

solar fluid every 4

years (after 60

months)

Table 3 – Solar fluid control

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6.4) Pipe Work Inspection

Insulation must be in good conditions to reduce thermal dissipation and efficiency

decreasing, especially in the accessories of connection.

In case of existence of pipes, crossing areas with personal movement, the pipes must

have mechanical protection.

Pict.46 – Missing Items: mechanical protection in cold water pipe and thermal insulation

in hot water pipe

Pict.47 – Correct insulation of connections of solar circuit

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Attention:

For guarantee activation, installer should communicate serial number and manufacturing

date visible in the sticker on the protection cover of the resistance and on the side of the

solar collector.

Pict.48 – Type plates and product identification

Annex Modifications included in TSS 3rd generation:

1) Changes on TSS Structure

a. Flat Roof – reduction of number of parts, reducing complexity

b. On Roof – improve of double ended screw support and reduction of

complexity in model TSS300 (independent collector installation and

separation of the structure fixation of the tank)

Example from collector 8370 – Plant identification; 004 – Manufacturing date (FD); 000016 – Counter number;

Example from tank 8370 – Plant identification; 004 – Manufacturing date (FD); 000005 – Counter number;

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2) Introduction of new solar collector FCB and FCC on TSS Systems (please check

FPI of SKW Project for details concerning collector)

Pict.49 – Detail of FCB / FCC collector

3) New Pressure relief valve

a. Horizontal Installation

b. Smaller dimensions

Pict.50 – System TSS200 with FCC Collector

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In terms of Installation, the following situations are accepted by after sales

1) Complete TSS system with Hooks only (please check)

Pict.51 – System installed with Hooks from image above

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2) Complete TSS system with double ended screw only (please check)

Pict.52 – System installed with double ended screws from image above

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3) TSS system installed with hooks in the collector area and double ended screw in

the storage tank support.

Pict.52 – System installed with both accessories and overview of change done in TSS 3rd

generation with the separation from collector fixation and tank

Pict.53 – System installed with double ended screw on tank structure and hooks in

collector area

Page 41 of 42

Pict.54 – For TSS300, collector profile support is with one length only as image shows

Pict.55 – Introduction of change in the double ended screw support in order to keep

profile in place

Page 42 of 42

Pict.56 – Overview of system installation

Pict.57 – Detail of change of TSS flat roof structure

Bosch, Termotecnologia, S.A

TT-GEH/STI – International Training and Technical Support

Aveiro Plant - Portugal