Lighting; Operating Hints; How Your Boiler Works - Potterton Powermax HE 85 User Instructions

Lighting

Check that the mains electricity and gas supply are both
turned ON. The amber neon on the control will light
when electricity is being supplied. Set the boiler On/Off
Switch to 'I' (ON), the boiler is now operational.
If the programmer is set to an ON period for Hot Water
the green 'burner' neon will light to indicate that the
burner has ignited and is heating the water (unless the
pre-set hot water temperature has already been
reached).
If the programmer is set to an ON period for Central
Heating the green 'burner' neon will light to indicate that
the burner has ignited and is heating the radiators
(unless the pre-set hot water store temperature has not
been reached or the system thermostat is not calling for
heat).
If the burner fails to light, the ignition sequence will be
automatically repeated until either the burner lights or a
safety Lock-Out condition is signalled by the red neon.
If the red neon lights note the error display code,see
Page 7. If appropriate, press the reset button on the
control panel and the boiler will re-set itself.

Operating Hints

When the burner is heating the water, the approximate
flow temperature can be indicated in the status display
window by a 't' for Hot Water or 'c' for Central Heating.
The temperature of the Hot Water can be adjusted by
turning the Temperature Control knob on the control
panel. The control temperature of this knob ranges
approximately from 45 °C to 65 °C. We recommend a
setting of 55 °C for normal operation.
During the summer period you can turn the Central
Heating off at the programmer. The life of the Central
Heating pump will be prolonged if you switch the Central
Heating on for a few minutes or so each week during the
summer period. Note: The boiler control will operate the
pump for a few seconds every day.
To turn the boiler off for short periods - set the central
heating and hot water channels to the OFF position at
the programmer. This leaves the boiler's built in frost
protection operational. To turn the boiler off for long
periods - set the boiler On/Off switch to the 'O' (OFF)
position and isolate the gas supply at the boiler. It may
be advisable to contact your Service Engineer if you
wish to do this.
Publication No. 5106228

How your boiler Works

Control of the Boiler
The boiler is fitted with a control panel which indicates
basic functions and also contains a programmer. If your
installer has fitted another make of programmer remote
from the boiler, the programmer display on the control
panel will operate as a clock only.
The burner automatically adjusts its heat output to meet
the demand of your central heating or hot water.
Central Heating
Your new Powermax HE works as part of a 'sealed';
pressurised hot water system which is why the boiler
has a pressure gauge and a means of re-filling the
central heating circuit.
Constant pressure in the pipework will find old or badly
made joints and allow water to weep or leak through.
Your installer should have advised you of this possibility
and recommended a course of action. It is not a fault of
the boiler.
Hot Water
To ensure a plentiful supply of hot water the Powermax
HE has a built in water store which during timed 'On'
periods is maintained around the selected temperature.
Your hot water taps may also leak due to the pressure
increase.
Hot water always takes priority over central heating
during a timed 'On' period. Where a significant volume
of hot water is drawn off (e.g. a bath) whilst the central
heating is on, the boiler will temporarily shut down the
heating until the required store temperature is restored
(this will typically take only 10 to 15 minutes).
Optional Immersion Heater
The hot water storage cylinder in your Powermax HE
may have been fitted with the optional electric
immersion heater. This is of a special type fitted with a
safety cut-out which switches off the heater in an
overheat situation. It is not interchangeable with
standard immersion heaters. Should it fail, use only a
genuine Powermax or Heatrae 'Mega' replacement
(Part No. P3223/5106143) which must be fitted by a
competent person.
A thermostat setting of around '3' (approx. 55 °C) is
recommended in hard water areas. Should the overheat
cut-out operate, it can be manually reset by pressing the
red button at the side of the thermostat dial. ALWAYS
investigate the cause of overheating before resetting.
User's Instructions 3