Operation In The Electricity Mode; Operation In Dual-Energy Mode; Operation In Auto-Relief Mode; Monitor Lights - Dettson LOW-BOY AME15-79 Guide D'installation Et Manuel Du Propriétaire

built-in High-Limit Control that prevents the burner from
overheating and damaging the furnace.
3.1.2

Operation in the ELECTRICITY mode:

When the three-position selector is on the ELECTRICITY
setting, the furnace operates like a conventional electric
warm-air furnace. When the thermostat is set high enough,
the fan comes on, followed by each of the elements in
sequence. When the call-for-heat has been met, the
elements go off-line sequentially, while the fan stays on until
residual heat is evacuated from the system. Each of the
elements is individually protected from overheating by way of
a Temperature Limit Control in the event of fan failure. A
removable panel under the oil burner provides easy access
to the electric elements.
Warm air from your furnace will naturally be cooler in the
electrical than the oil mode since the electrical output is 5
kW lower. It is imperative that airflow adjustments be made
in the oil mode where it is most critical. Once the call-for-h-
eat has ended, the elements go off-line sequentially,
separated by a 12 second delay.
When switching from oil to electricity, there is a five-minute
delay between burner shutdown and the elements coming
on-line in order to guard against overheating.
3.1.3

Operation in DUAL-ENERGY mode

When the three-position selector is on the DUAL-ENERGY
setting, the furnace micro processor is on-line with Hydro.
When the call-for-heat comes through, the processor
determines whether to heat with oil or electricity. The
electronic control system can also switch the furnace from
one mode to the other during a heating cycle. It is important
to note that there is a five minute delay between burner shut
down and the elements coming on.
3.1.4

Operation in AUTO-RELIEF mode

A factory-installed thermosensor, located on the left side of
the inside top portion of the component panel, relays
temperature readings to the board. The sensor requires no
adjustment or modification. If, during a period of 15
consecutive minutes, the sensor records temperatures under
38° C (100° F) while the thermostat circuit is closed , the board
will assess an abnormal operation and implement auto-relief.
In basic terms, this means simply changing the heating
mode.
When the AUTO-RELIEF indicator light comes on, the
furnace has detected a problem with one energy source and
has automatically shifted to the other. If the furnace is
operating electrically, with both the AUTO-RELIEF and
ELECTRIC lights on, there is a burner problem. If the
furnace is in the oil mode, with both the AUTO-RELIEF and
OIL lights on, there is a problem with the electrical system.
Twelve hours following detection of AUTO-RELIEF, the
furnace will try once again to operate with the power source
indicated on the three-position switch:
dual-energy, according to the signal from Hydro. The
process will repeat itself every twelve hours. Obviously, if the
problem persists, the
AUTO-RELIEF mode. The only way to get out of this mode,
in such a situation, is to manually reset the furnace by
cutting and then restoring the main power supply.
oil, electricity, or
furnace will remain in
3.1.5

Monitor Lights

These lights, which indicate the operating state of the
furnace, are located just below the three-position selector on
the outside of the electrical compartment door.
OIL light alone
This indicates that the furnace is operating on OIL solely and
is not in the dual-energy mode.
OIL light with DUAL-ENERGY light
This indicates that the appliance is in the DUAL-ENERGY
mode, but operating on OIL at the moment.
ELECTRICITY light alone
This indicates that the furnace is operating solely on
ELECTRICITY and is not in the dual-energy mode.
ELECTRICITY and DUAL-ENERGY lights
This indicates that the appliance is in the DUAL-ENERGY
mode, but operating on electricity at the moment.
AUTO-RELIEF and OIL lights
When both these lights are on, there is a problem with the
ELECTRICITY mode. The dual-energy light may or may not
be on.
AUTO-RELIEF and ELECTRICITY lights
When both these lights are on, there is a problem with the
OIL system. The dual-energy light may or may not be on.
3.1.6

Operating in the EMERGENCY mode

In the case of an electronic board malfunction or breakdown,
the emergency mode enables the furnace to run on OIL, by
using the emergency switch located between the thermostat
connection terminal strip and the ventilation switch in the
burner cabinet. When the thermostat calls for heat, the
burner is energized and the blower is controlled by the Fan-
Limit Control.
The transfer to the emergency mode is not automatic,
but must be effected manually, as required. The
EMERGENCY MODE must only be used as a temporary
means of heating. The problem that caused the
activation of this mode in the first place must be
repaired as soon as possible. For further details see
Part 4 of this manual.
3.2

OPERATING IN THE OIL MODE

3.2.1

Operational checklist

Before starting up the unit, be sure to check that the
following items are in compliance:
the
1. The electrical installation, the oil supply system, the
venting system, combustion air supply and ventilation;
2. The blower access door secured in place;
7
WARNING