Nordica TERMOSOVRANA Installation, User And Maintenance Instructions page 25

TERMOSOVRANA
The diameter of the opening for connection to the chimney must at least correspond to the diameter of the
flue gas pipe. The opening must be equipped with a wall connection for the insertion of the exhaust pipe
and a rosette.
The unused flue gas exhaust stub pipe must be covered with its respective cap.
It is COMPULSORY that the thermo cooker model TERMOSOVRANA is installed in an OPEN expansion
VESSEL system.
It is COMPULSORY that the OPEN expansion VESSEL system is provided with:
1. OPEN EXPANSION VESSEL: with a capacity of 10% of the total water content of the thermocooker
and the system. This must be positioned at the highest point of the system, at least 2m above the
radiator placed at the highest level.
2. SAFETY PIPE: that connects by means of the shortest path without descending routes or siphoning the
flow of the thermo cooker with the top part of the tank described in point 1. The safety pipe must have
the minimum gas section of 1".
3. LOAD PIPE: that connects the bottom of the tank of point1 with the system's return pipe.
It must have a minimum gas section of ¾''.
All these elements must not, for any reason, have intercepting objects inserted, as these could
accidentally exclude them, and they must be placed in an area not subject to freezing, seeing that, if
they should freeze, the boiler frame could break or even explode.
In case of exposure to ice, it is opportune to add a sufficient quantity of anti-freeze to the water in the
system, enough to completely eliminate the problem.
In no way should water circulate in the small tank in-between the safety pipe and load pipe, seeing as
this oxidises of the water and consequently this quickly corrodes the thermo cooker and system body.
4. HEAT DISCHARGE VALVE: permits an extra positive safety, capable of preventing boiling, even if
there is no electric power.
It consists of a valve, similar to a pressure safety valve, but differs, seeing that it opens once the pre-
calibrated temperature (normally 94-95° C) is reache d. It discharges hot water from the system flow
pipe, and the water is replaced with the same quantity of cold water, supplied from the tank vessel load
pipe, this way reducing the excessive heat.
5. SAFETY VALVE FROM 1,5bar: maximum operation pressure allowed for the system is 1,5 bar (equal
to 15m of the water column). Higher pressures can cause deformation and breakage of the boiler body.
6. SAFETY DEVICES envisioned by Regulations in vigour.
7. CIRCULATION PUMP: preferably fitted on the return pipes to avoid diffusion of extremely high
temperature water, however ensure that it does not make water circulate in the open vessel tank as this
would cause continuous oxidation of water which would quickly corrode the boiler body.
It must also be connected electronically so that it will only work when the water temperature reaches
65-70° C. To achieve this one can use the electronic control unit, available as an OPTIONAL with the
thermo cooker, or by using a sleeve thermo switch fitted directly on the flow pipe and calibrated at 65 -
70° C.
8. AUTOMATIC THERMOSTATIC MIXING VALVE - Figure 2
The automatic thermostatic mixer valve finds applications in solid fuel heat generators as it prevents
cold water return in the exchanger.
Routes 1 and 3 are always open and, along with the pump installed on the return (R), the guarantee
water circulation inside the biomass boiler exchanger (CB).
An elevated return temperature, allows efficiency improvement, reduces formation of smoke
condensation and prolongs the boiler life span.
Valves on the market have different calibrations. NORDICA advises use of model 55° c with 1"
hydraulic connections. Once the valve calibration temperature is reached, route 2 is opened and the
boiler water is goes to the system via the flow (M).
Instructions for installation, use and maintenance – EN – Rev.03 25