Quick Start Manual

3.0 Appliance Operation

NOTE: All delay timers mentioned in 3.1 and 3.2 are

overridden by domestic hot water demand.

3.1

Central Heating Mode

1. With a demand for heating, the pump circulates water

through the primary circuit. At a flow rate of

approximately 4.5 l/min the central heating flow switch

operates, initiating the ignition sequence.

2. The main burner ignites at a low rate, then the fan/gas

valve and proportionator control the gas rate to maintain

the heating temperature measured by the thermistor

sensor.

3. When the flow temperature exceeds the set

temperature, a 1 minute pump overrun occurs followed

by 3 minutes anticycle. If the flow temperature is low

enough the burner will then relight automatically

otherwise pump overrun and anticycle will occur again.

4. When the demand is satisfied the burner is

extinguished and the pump continues to run for a period

of 1 minute (Pump Overrun).

3.2 Domestic Hot Water Mode

1. Priority is given to the domestic hot water supply. A

demand at a tap or shower will override any central

heating requirement.

2. The flow of water will operate the DHW flow switch

and the 3-way valve will change position. This will allow

the pump to circulate the primary water through the

DHW plate heat exchanger.

3. The burner will light automatically and the temperature

of the domestic hot water is controlled by the return

thermistor.

4. When the domestic hot water demand ceases the

burner will extinguish and the diverter valve will remain in

the domestic hot water mode, unless there is a demand

for central heating.

3.3 Boiler Frost Protection

1. The boiler incorporates an integral frost protection

feature. It will operate in both summer and winter modes.

If the boiler temperature falls below 8°C (± 5°) then the

boiler will fire until a temperature of 15°C (± 5°) is

reached.

3.4 Pump Protection

1. The control system continually monitors the time since

the pump last operated. This will result in the pump being

run for 1 minute if it has not run in the last 24 hours to

prevent seizure.