Baxi Potterton Solar manual Check pressure in the solar primary, Pipework, From air

Fig. 4

1

	2.0	Commissioning of hydraulic station
	2.1	Check pressure in the solar primary
		pipework
	After flushing and filling the solar primary system with
	heat transfer fluid the pressure must be checked.
	Pressure test the system (6 bar). Observe the maximum
	pressure ratings of all components concerned.
	Check the solar heating system for leaks.
	Close the fill and drain valve on the safety group.
	2.2	Ensure the solar primary system is free
		from air
	Switch on the power supply to the solar differential
2	temperature controller.
	Manually switch the circulation pump ON and OFF
	via the solar differential temperature controller
	(see section 3.1.7) to pump fluid around the solar
	primary system.
	Turn the pump off and open the airbleed screw on the
	air separator (Fig. 4 Item 1). Bleed any air from the air
	separator. If the system pressure drops top up by opening
	the fill and drain valve (Fig. 4 Item 2) on the safety group
	and pumping in more solar fluid to restore the pressure.
	This must be repeated until the pressure remains stable.
	2.3	Setting the system pressure
	During	commissioning, the system pressure should be
	0.7 bar above the static pressure (1 metre height
	differential equals 0.1 bar). However,it must be at least
	1.5 bar and no higher than 2.2 bar.

Determine the system pressure when the system is cold (20°C).This should be recorded on the Commissioning Record Sheet (page 21).

If the pressure is too low you should pump additional heat transfer fluid into the system; the fill & drain valve on the safety group (Fig. 4 Item 2) needs to be opened for this purpose. When system pressure is correctly set, ensure the fill and drain valve is closed and remove filling hose from safety group.

Potterton Solar - Solar Thermal Domestic Hot Water System 5