PRIMARY COIL CONNECTIONS
Connect the primary connections ( Indirect only ) using the compression connections provided. The primary circuit must be
positively pumped. Gravity circulation is not suitable. Either primary connection may be used as the primary flow. Reheat times
are identical either way. The primary circuit can be open vented or sealed with up to a maximum pressure of 3.5 bar. If you seal
the primary circuit an additional expansion vessel and safety valve is required. The boiler may be Gas, Electric, or Oil but must
be under effective thermostatic control. Uncontrolled heat sources such as some AGA’s, back boilers, solid fuel stoves, etc are
NOT SUITABLE. Please contact our technical department for guidance. Connect the two port zone valve ( indirect only ) into the
primary flow pipework. The direction of flow arrow should be towards the primary flow connection. On twin coil solar cylinders we
have provided an extra thermostat boss should you wish to use it. Again a two port zone valve should be fitted (supplied).
For Solar products refer to pages 10-13.