3.4.2 Operation of the thermal safety valve.
The thermal safety valve is a safeguard that works on the basis of cold mains water. When the temperature at the
valve's detector becomes too high, the valve will open. In that case, cold mains water is sent through the cooling
coil in order to discharge excess heat. Mixing of mains water and water from the heating system is not possible, as
the cooling coil is separated from the central heating boiler.
The safety valve opens at 95 °C (+/-3 °C) and makes sure that the temperature of the central heating boiler
remains below 110 °C.
3.4.3 Pressure relief valve
Overpressure can damage the appliance and its components. In order to prevent overpressure, the system is
supplied with a pressure relief valve.
The pressure relief valve should be installed at all times! Without this valve, it is impossible to guarantee a safe
Caution!
operation of the system. For a safe and correct operation of the pressure relief valve, please take the following into
account:
Ø
Connect the pressure relief valve to the fire;
Ø
For this, use a pipe with a minimum diameter of ½";
Ø
Valves and resistors are not allowed in the pipe;
Ø
Place the pressure relief valve maximum 1 metre away from the appliance.
The supplied pressure relief valve has a maximum operating pressure of 3bar.
!Tip
The pipe from the pressure relief valve to the discharge must comply with the following requirements.
Caution!
In case of a pipe with a maximum length of 2 metres it applies that:
•
•
•
In case of a pipe with a maximum length of 4 metres it applies that:
•
•
•
If this valve should be replaced, a valve with the exact same specifications must be mounted. Mount the blow-off
pipe of the pressure relief valve outside of the direct reach of persons. For the benefit of periodic tests, the
pressure relief valve should be mounted on an accessible location.
3.4.4 De-aeration
A good de-aeration is very important for the system's operation. For a good de-aeration, proceed as follows:
At the top, at the rear of the appliance, there is a female thread socket in which the de-aeration system should be
mounted (see appendix 2, figure 1, G);
•
•
3.4.5 Boiling-dry safeguard
It is possible that steam is generated in a fire that is half-filled with water. This could result in highly dangerous
Caution!
situations. The risk that steam is generated occurs when radiators, buffer vessels or other water-filled elements
within the system are below the level of the fire. At all times, ensure a de-aeration system with a correct water
pressure.
EN
28
the maximum number of bends in this pipe is 2;
the minimum diameter of this pipe is ½";
it may not have any valves and resistors.
the maximum number of bends in this pipe is 3;
the minimum diameter of this pipe is ¾";
it may not have any valves and resistors.
Provide the system with de-aeration facilities in the supply and return.
If air accumulates in the system, the pump will be unable to transport the central heating water properly. In
that case, because of temperatures that are too high, the temperature safeguard may be activated before the
appliance supplies hot water to the system.
I N S T A L LA T I ON M A N U A L