Supplied By www.heating spares.co Tel. 0161 620 6677
14
DOMINA PLUS F 24 - 30 E
FERELLA EXTRA F 24 - 30 MEL
Version - 09.2002
Hydraulic unit
This is a single piece of brass to which the exchanger
delivery is connected for ease of access. It
accommodates a number of safety and adjustment
components.
The hydraulic unit includes:
- safety valve
- water pressure switch
- heating sensor
- filler cock
- tap water sensor
- tap water check valve
Filler cock
This is located between the heating delivery and the tap water outlet. It is not fitted
on the boiler for some markets such as the British and Belgian ones.
Check valve
This is necessary to ensure no water returns from the heating system to the tap
water circuit.
Safety valve
It opens if the pressure exceeds 3 bars, making boiler operation safer and
protecting it against overpressure. You are strongly recommended not to use this
valve to drain the system; once open, dirt could remain inside it, preventing it from
closing completely.
Water pressure switch
It ensures a minimum pressure for the system. It is normally open (NO) and
closes the contact when the pressure exceeds 0.5 bar. It works on low voltage.