Extraflame Lucrezia - Instant Domestic Hot Water Production Accessory Kit; 8 Automatic Thermostatic Mixer Valve; Automatic Thermostatic Mixer Valve (Mandatory); Mandatory

AUTOMATIC THERMOSTATIC MIXER VALVE MANDATORY
14
Closed expansion vessel
The vessel maximum exercise pressure must not be lower than the calibration
pressure of the safety valve, increased by overpressures, characteristic of the same
valve, bearing in mind the eventual level dierence between vessel and valve
and the pressure generated by the functioning of the pump. The capacity of the
expansion vessel/s is evaluated depending on the total system capacity as results
from the project. The closed expansion vessels must comply with the dispositions
regarding the planning, manufacturing, evaluation of conformity and use for
pressure appliances. Intercepting objects or section decreases must be inserted/
practiced on the connection piping, which can be constituted by system portions.
The insertion of a three-way intercepting valve which allows connection between
the vessel and the atmosphere for maintenance operations, is allowed. Such device
must be protected against accidental manoeuvres. The connection pipe must be
realised in order not to present scales or deposits storage points. In case of more
heat generators which feed the same plant or the same secondary circuit, each heat
generator must be connected directly to the expansion vessel or plant expansion
vessels unit, altogether dimensioned for the total volume of water contained in the
same plant or the same independent circuit. Where it is necessary to separate the
individual heat generator from the expansion vessel or expansion vessels unit, a
three-way tap must be applied on the connection piping between the generator
and the vessel, in order to ensure, in every position, the connection of the generator
with the expansion vessel or with the atmosphere. The expansion vessels, the
connecting pipes, the bleed pipes and drain pipes must be protected from freezing,
where this phenomenon occurs. The solution used for this purpose is described in
the design.
Commissioning checks
Before connecting the boiler:
a) wash all system piping in order to remove any residues which might compromise
the correct functioning of certain system components (pumps, valves, etc.).
b) check to verify that the ue has adequate draft, is not narrowed and that other
appliances do not discharge into the ue.
This is to prevent unexpected power increases. Only after this control can the
chimney tting between the boiler and ue be mounted. It is recommended to
control the ttings with pre-existing ues.
Feeding water features
The chemical-physical features of the system and reinstate water are fundamental
for the correct functioning and life-span of the boiler.
Amongst the inconveniences caused by bad quality feeding water, the most
frequent is the scaling of the heat exchange surfaces.
Less frequent, but equally serious, is the corrosion of the water side surfaces of the
entire circuit.
It is known that the lime scale, even if there is only a few millimetres, due to their low
thermal conductivity, greatly reduce the heat exchange, determining damaging
localised heating. It is strongly recommended to treat the water in the following
cases:
a) very hard water available (higher than 20°f)
b) very extended systems
c) large water quantities restored due to leaks
d) subsequent llings due to system maintenance work
It is recommended to always contact specialised companies to treat the feeding
water of the heating systems.
Filling the system
Once the hydraulic connections have been carried out, proceed to connecting the
plant.
Open all air venting valves of radiators, boiler and plant.
Gradually open the load cock ensuring that the air venting valves work regularly.
Using the manometer, check that the system is pressurised. In case of closed vessel
system, reach the pressure of about 0.11 – 0.12 MPa (1.1 – 1.2 bar). Close the load
cock and again release the air from the boiler through the venting valve.
AUTOMATIC 8.
THERMOSTATIC MIXER VALVE
MANDATORY
The automatic thermostatic mixing valve nds applications in solid
fuel boilers as it prevents cold water return into the exchanger.
Routes 1 and 3 are always open and, together with the pump
installed on the return, they guarantee water circulation inside the
biomass boiler exchanger. An elevated return temperature, allows
eciency improvement, reduces formation of combustion product
condensation and prolongs the boiler life span.
Valves on the market have dierent calibrations. The company
advises use of 55°C model with 1" hydraulic connections. Once the
valve calibration temperature is reached, route 2 is opened and the
boiler water goes to the system via the ow.
It is recommended not to use this device whenever the DHW is
produced through an instant heat exchanger.
INSTANT DOMESTIC 9.
HOT WATER PRODUCTION
ACCESSORY KIT
Warnings: if the instant hot water production accessory kit is to be
used, contact the company technical after-sales service.