Vasoflex - Boiler Baxi - Free user manual and instructions

Product type	Solar thermal system for domestic hot water
Brand	Baxi
Model	Vasoflex
Category	Boiler (solar thermal)
Use	Production of domestic hot water using solar energy
Heat transfer fluid	Water-glycol mixture with corrosion inhibitors
Recommended glycol concentration	26% to 51% depending on minimum temperature (from -10°C to -35°C)
Optimal orientation	South (or West if not possible)
Optimal tilt	Geographic latitude (annual), latitude+10° (winter), latitude-10° (summer); range 15°-75°
Operating pressure	2 bars cold (add static pressure), max 10 bars
Expansion vessel	Required on primary circuit, sized according to DIN 4757, EN 12977 or VDI 6002
Piping	Copper or stainless steel, minimum slope 1%
Pump	Install with horizontal axis, avoid cavitation
Bleeding	Required (manual or automatic), activate only when system is cold
Fluid pH	Must be between 7.5 and 8.5; if <7.0, replace the fluid
Maintenance	Check every 6 months (area >20m²) or 1 year (area <20m²): condition of collectors, tightness, pressure, pH, glycol, bleeding
Safety	Safety valve, electrolytic sleeves, freeze protection
Installation	By authorized personnel, comply with DTU and local regulations

Frequently Asked Questions - Vasoflex Baxi

What is the optimal orientation for Vasoflex solar collectors?

The optimal orientation is south. If not possible, favor west. Avoid any shading on the collectors.

What tilt angle should be chosen for the collectors?

The tilt depends on usage: geographic latitude for annual use, latitude+10° for winter priority, latitude-10° for summer. Possible range: 15° to 75°.

What heat transfer fluid should be used?

Use a mixture of water and glycol with corrosion inhibitors. The glycol concentration depends on the minimum temperature: 26% for -10°C, up to 51% for -35°C. Do not exceed 50% to avoid excessive viscosity.

How to check the pH of the heat transfer fluid?

The pH must be between 7.5 and 8.5. If the liquid is dark or cloudy and the pH is below 7.0, replace the fluid.

What pressure should be maintained in the primary circuit?

When cold, the pressure must be at least 2 bars (adding the static pressure due to height). The maximum pressure is 10 bars.

How often should maintenance be performed?

For installations larger than 20 m², a check every 6 months is required. For installations smaller than 20 m², an annual check is sufficient.

How to bleed air from the system?

Activate the bleeder only when the system is cold. During normal operation, the high temperature of the fluid can cause burns. After filling, check the system the first few weeks to remove residual air.

What materials should be used for the piping?

The primary circuit piping must be in copper or stainless steel, with threaded, welded, or flanged connections. Horizontal sections must have a minimum slope of 1%.

How to install the expansion vessel?

Install the expansion vessel on the primary circuit, near the hydraulic group, preferably at the pump suction. No shut-off device should be placed between the vessel and the installation. Size it according to DIN 4757, EN 12977 or VDI 6002.

What to do in case of a leak or failure?

In case of a leak, repair and bleed the system again. Never fill the primary circuit with tap water if it may cause scaling or if an antifreeze is necessary. Check the pH and glycol concentration after repair.

USER MANUAL Vasoflex Baxi

Simple line drawing of a tilted rectangular object on an inclined stand, enclosed in a circular frame (no text or symbols)

Simple geometric diagram of a rectangular frame with hatched fill, no text or symbols present

Architectural line drawing of a square foundation or structural grid (no text or symbols)

1. Please read these instructions before installing or commissioning the solar system.
2. Please leave these instructions with the user for later reference.
3. This solar thermal energy system for domestic hot water should only be installed and handled by competent, authorised personnel.

During works, you must obey:

• The legal provisions on accident prevention.
• Environmental legislation.
- All occupational health and safety provisions in force.
- Specific EU safety regulations and the rules and regulations of the individual country.

Keep the collector protected from the elements and in its original packaging until installation.

To transport the collector, we recommend handling it in its packaging with the aid of aluminium frames. Do not handle the collector by its hydraulic connections. Protect the collector from knocks or other mechanical influences, especially the solar glass, rear of the collector and hydraulic connections.

Cover the collector during installation until it is fully operational, as this will prevent it from reaching high temperatures due to solar radiation.

The installer is responsible for ensuring compliance with all specific regulations in the individual country or region.

ORIENTATION AND TILT OF THE COLLECTOR

The best orientation of the solar collector is southward; if it is not possible to orient the collector in a southerly position, point it in a westerly direction.

The best tilt angle will depend on when the system is used, which may be:

a) Constant year-round demand: geographical latitude.
b) Demand mainly in the winter: geographical latitude +10°.
c) Demand essentially in the summer: geographical latitude -10°.
d) Collectors can be installed in installations with an inclination angle ( ) comprised between 15° and 75°

Avoid any shadows that could affect the solar collectors. Losses due to orientation, tilt and possible shadows over the system must be kept at or below the minimum levels permitted in the applicable regulations.

GENERAL CONDITIONS OF INSTALLATION

All systems will have independent primary (with heat-transfer fluid) and secondary circuits. Avoid mixing the different fluids.

They must all meet the regulations in force and specific legislation on protection against electric shock.

Electrolytic sleeves must be installed between parts of different materials to prevent galvanic coupling.

WORKING FLUID

The installer or designer will set the minimum allowed temperature of the system. Components located outside must be able to withstand this temperature without permanent damage. The system should be protected against temperatures of 5^ C below the lowest historical figure recorded with a non-toxic chemical fluid designed for this purpose.

Freezing point (°C) -10 -15 -20 -25 -30 -32 -35
Glycol concentration (%) 26 33 37 42 47 50 51

IN OUT

Technical line drawing of a pressure vessel with piping and valves (no text or labels)

Pure schematic diagram of a water supply system with tanks and piping (no text or labels)

We recommend the use of a directly applicable mixture of water and glycol with corrosion inhibitors. Avoid increasing the concentration by large amounts; it should never exceed 50% because this would create a mixture with very high viscosity levels, thereby reducing the heat-transfer properties of the fluid. DO NOT mix with any other fluids.

Although this fluid is non-toxic, odourless and biodegradable, it should be handled with caution. The use of chemical-resistant gloves and eye protection is recommended when handling this fluid.

If the fluid comes into contact with the skin, wash with soap and water. In case of contact with the eyes, rinse immediately with plenty of clean running water.

COLLECTOR INSTALLATION

If more than one row is required, the collectors must be installed in a multiple parallel arrangement, preferably with the same number of collectors in each row. Cut-off elements will be installed to separate each row. A safety air vent valve will be installed in each row; if an automatic air vent valve is used, a cut-off valve will be installed to disable the valve while the system is in operation. We must also ensure that there are no reverse flows, as doing so will prevent energy losses.

Temperature probe

Temperature sensors should be installed in such a way as to ensure good contact with the measuring point. They should be insulated from the influence of environmental conditions and installed against the flow of the fluid. The temperature probe will be installed at the hottest point of the output of the corresponding row.

⚠ Ensure correct installation of the thermal sensor in the collector. Secure the sensor wire with a suitable material to prevent its accidental removal from the collector.

Special attention must be paid to the maximum temperatures reached in the last collector of the row as the solar liquid may become deteriorated.

Expansion tank

An expansion tank will be installed in the primary circuit close to the hydraulic unit, in line with the size and characteristics of the installation. The size of the expansion tank will be calculated according to DIN 4757, EN 12977 or VDI 6002. This expansion tank will be installed:

1. Such that the temperature of the water touching the membrane is as low as possible.
2. Preferably in the pump suction line.
3. Cut-off elements should not be installed between the expansion tank and the system.

Pipes

The pipes will be as short as possible and allow for complete draining. Horizontal sections will have a minimum slope of 1%. The pipes of the primary circuit may be made of stainless steel or copper and have threaded, welded or flanged joints. Outdoor pipes must have external protection to enable them to withstand the effect of the weather and avoid transport losses.

The recommended sizes of pipe to maintain a pressure drop of less than 2.5 mbar per linear meter are:

m^2	5					7.5					12.5					25
l/h*m^2	15	20	30	40	60	15	20	30	40	60	15	20	30	40	60	15	20	30	40	60
l/h	75	100	150	200	300	113	150	225	300	450	188	250	375	500	750	375	500	750	1000	1500
min. int. ∅	DN13	DN13	DN13	DN16	DN16	DN13	DN13	DN16	DN16	DN20	DN16	DN16	DN20	DN20	DN25	DN20	DN20	DN25	DN25	DN32

Pumps

Where possible, the pump should be assembled in the cooler parts of the circuit, ensuring that there is no cavitation, and always with a horizontal axis of rotation.

To calculate the size of pump to install, we must take account of the pressure drop in the collectors installed, as well as pipe losses.

Collector connection

The optimal connection (parallel connection) is by crossing over the row of input and output collectors from opposite ends; they can be also connected from the same end of the row of collectors with barely any loss of performance.

COMMISSIONING

The first thing we must do after installation is clean the system to remove any residual welding slag, remover or dirt in the pipes.

Use a container large enough to collect the fluid. Once the circuit has been flushed, we can start filling the system.

The system must be filled without direct sunlight; if this is not possible, cover the collector or collectors during filling and flushing. Otherwise, there may be a risk of vapour formation..

Pressurise the system to 1.5 times the working pressure to detect for leaks. If any leaks are detected, eliminate them all from the system.

Alternatively, an air test can be conducted to detect any major losses in the system before flushing and filling with the heat-transfer fluid.

During filling and commissioning, the system must be completely drained. We recommend re-testing the system during the first weeks of operation to release any air

In case of breakdown or drops in the system, you will need to vent the air again when refilling. NEVER fill the primary circuit with tap water if its properties could lead to the formation of incrustations, deposits or attack on the circuit, or if the circuit needs antifreeze due to the risk of frost or any other additive to function properly.

Note: Only operate the air vent when the system is cold. During normal operation, the heat-transfer fluid reaches high temperatures and can cause severe burns.

Check the pH valve at regular intervals to make sure that it is between 7.5 and 8.5. If the fluid is dark or cloudy and the pH value is below 7.0, the heat-transfer fluid must be replaced.

The percentage of glycol in the heat-transfer fluid should be checked every two years. This can be done using a refractometer.

Note that the cold pressure in the collectors should be above 2 bar. Since the filling pressure gauge is located in the bottom part of the installation, we must add the static pressure of the system when taking the reading. The maximum permissible temperature for the system is 10 bar.

After commissioning, do not forget to close all manual and automatic vents.

Once the system has been flushed, drained and has the correct pressure, we must regulate the flow of the system. To do so, we will need to adjust the pump flow to the lowest possible speed (to minimise electrical consumption) and regulate the flow using a flow meter.

The following lists include the most important maintenance operations for an installation.

1. Check the proper functioning of the system Perform this checklist during commissioning.

☐ Check the seals and hydraulic connections of the solar collectors to the system.
☐ Check the solar collector mounting kit system.
☐ Check for leaks in the hydraulic circuit.
☐ Check that the heat-transfer fluid used in the system is composed of a mixture of antifreeze and water.
☐ Check the installation of safety elements: expansion tank and safety valve.
☐ Check the connections and operation of the regulation system of the installation.

1. Check on general system status

The following checks cover the operations needed to maintain the system within the acceptable limits of operation, performance, protection and durability. These operations must be carried out by competent technical staff with expertise in solar thermal technology and mechanical installations in general. The maintenance register of the system must be kept up to date. The maintenance of systems with a collector area of over 20 m ^2 must undergo inspection at least every six months. Those of less than 20 m ^2 should be inspected on an annual basis.

State of repair of collectors:

	Presence of condensation and dirt
	Presence of cracks, deformation
	Presence of corrosion
	Appearance of leaks
	Verification of temperature probe mounting

State of repair of the collector support structure and its fixing elements:

	Degradation, signs of corrosion and bolt tightening
	Condition of collector fixing elements
	State of repair of roof around the solar system
	Control of vegetation around the collector
	Check on ballast tray, where necessary

Hydraulic circuit:

	Presence of air inside the system
	Check on correct operation and cleaning of air valve
	Inspection to determine deterioration of insulation
	Pressure test
	Presence of leaks
	Pump seal
	Pump operation while the system is running
	System flow check
	Check on refrigerant density using a refractometer
	Check to ensure that the pH value of the refrigerant is pH>7.5

Verification of operating pressures:

	Check on system pressure
	Check on expansion tank pressure

Security system

	Actions (opening and closing) to check for cut-off valve stiffness
	Presence of glycol in the collection tray
	Check on safety valve operation

Regulation system:

	Check on pump shut-down and start-up differential
	Check of reading of the system's temperature sensors

INTRODUCTION

Technical line drawing of a pressure vessel with piping and valves (no text or labels)

Pure schematic diagram of a water circulation system with no text, numbers, or symbols

Pure technical diagram of a piping system with valves and a pressure vessel (no text or labels)

Pure schematic diagram of a fluid system with tanks, valves, and piping (no text or labels)

β N O ← → E α S

Technical line drawing of a pressure vessel with piping and valve components (no text or labels)

Pure schematic diagram of a water circulation system with tanks and piping (no text or labels)

β N O ← → E α S

Technical line drawing of a pressure vessel with piping and valves (no text or labels)

Pure schematic diagram of a fluid system with two tanks and piping (no text or labels)

β N O ← → E α S

Pure technical diagram of a piping system with valves and a pressure vessel (no text or labels)

Pure schematic diagram of a water circulation system with no text, numbers, or symbols

β O ← α S N E

ALLGEMEINE INSTALLATIONSBEDINGUNGEN

Technical line drawing of a pressure vessel with piping and valves (no text or labels)

Pure schematic diagram of a fluid system with tanks, valves, and piping (no text or labels)

β N O ← → E α S

Pure technical diagram of a piping system with valves and a pressure vessel (no text or labels)

Pure schematic diagram of a water supply system with tanks, valves, and piping (no text or labels)