Baxi Potterton 105 HE Central Heating System Pressure, To Shut Off the Boiler

Pressure Gauge

2

1 3

0 4

bar

Fig. 15

Normal Pressure (when cold)

2

1 3

0 4

bar

Fig. 16

Normal Pressure (operating)

2

1 3

0 4

bar

Fig. 17

Fault

2

1	3
	4

bar

Fig. 18

Below Minimum

ON/OFF

Selector Switch

Reset

Fig. 19

OFF Position

3.0Operating the Boiler

3.9Central Heating System Pressure

1.The water pressure in the central heating system is indicated by the pressure gauge.

2.With the system cold and the boiler not operating the pressure should be between 0.5 and 1.0 bar. During operation the pressure should not exceed 2.5 bar, and will normally be between 1.0 and 2.0 (Figs. 15 & 16).

3.A pressure of 3 or greater indicates a fault. The safety pressure relief valve will operate, at a pressure of 3 (Fig. 17). It is important that your Installer or Service Engineer is contacted as soon as possible.

4.The MINIMUM pressure for correct operation is 0.5. If the pressure falls below 0.5, this may indicate a leak on the central heating system (Fig. 18).

3.10To Shut Off the Boiler

1.For short periods: Turn the selector switch to the OFF position (Fig. 19).

2.For long periods: Turn off the selector switch (Fig.19), electricity and gas supplies.

If your home is to be left unoccupied for long periods during cold weather the boiler and whole system should be drained unless there is additional frost protection.

3.Your installer will advise you about frost protection and draining the system.

IMPORTANT: When the selector switch is in the ‘0’ (Off) position the electrical supply to the boiler is isolated. The boiler will not operate and the integral timer (if fitted) will require resetting once the selector switch is set to either Position (i) or Position (ii).

3.11Frost Protection Mode

1.The frost protection feature will operate when the selector switch is in the central heating and domestic hot water mode.

The gas and electrical supplies to the boiler must be on and the system pressure must be within the range described in Section 3.9.

2.If the system temperature falls below 5°C, then the boiler will fire until the water temperature has been raised.

3.Further frost protection can be incorporated by using a frost thermostat to protect the whole system.

© Baxi Heating UK Ltd 2007 9