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ENGLISH
Jandy
®
LXi
™
Model Pool and Spa Heater by Zodiac
®
|
Installation and Operation Manual
ignition control then applies electrical power to
a “hot surface” igniter. When the igniter is hot
enough, the ignition control opens the gas valve.
It has sophisticated means to sense ignition and
flame condition so that unburned gas will not es-
cape. Once the ignition control has sensed flame,
it de-energizes the igniter. After the burner is shut
off, the ignition control continues blower opera-
tion to provide a post-purge period.
5.
Igniter -
The hot surface igniter is a crystalline
element which becomes very hot when electri-
cal power is applied to it. The hot surface igniter
directly ignites the air/gas mixture in the combus-
tion chamber.
6.
Limit Switches -
Two (2) limit switches prevent
excessive water temperature - one at the heat
exchanger outlet and one (1) for water leaving
the heater. If either senses excessive temperature,
burner operation is interrupted.
7.
Water Pressure Switch
- This control senses
whether or not water is available to the heater by
measuring back pressure inside of the heat ex-
changer. If the pool water pump fails or the water
filter is blocked, the pressure switch prevents
operation of the burner.
NOTE
: The air box fusible link maximum temperature
is 152°C. The vent box fusible link maximum
temperature is 240°C and is identified with red
paint. DO NOT interchange these fusible links.
8.
Roll-Out (Fusible Link) 152°C (305°F) -
This
is a single-use switch which detects abnormal
temperature in the component compartment of
the heater. It is a roll-out (fusible link) which is
held to the combustion chamber just above the
burner tray by a sheet metal bracket. Excessive
temperature in the component compartment,
possibly due to a burner flash-back will cause the
switch to fail. This opens the safety circuit which
shuts off the gas valve and shuts the heater down.
9.
Vent Temperature Limit 240°C (464°C)
- This
is a single use switch which detects abnormal
temperatures in the vent system. It is mounted to
the vent box. Excessive temperatures will cause
the switch to open. Excessive temperatures can
be caused by inadequate water flow or a dam-
aged heat exchanger. The vent temperature limit
switch will open the safety circuit which shuts off
the gas valve and shuts down the heater.
10.
Air Pressure Switch -
This switch verifies that
air is flowing through the combustion system by
sensing pressure. It shuts off the heater if air flow
is inadequate.
11.
Flame Sensor -
The flame sensor is the electrode
through which the ignition control detects "rec-
tification" of current passed through the flame.
Inadequate rectification indicates an unsatisfac-
tory flame condition. The rectification signal
can be measured by attaching the leads of a DC
ammeter to the two pins on the connector of the
ignition control labeled "FC". A wire harness,
available from Zodiac Pool Systems, Inc., makes
it easier to attach the voltmeter leads. The flame
current should not be less than 1.5 micro-amps.
If the flame signal is less than 1.5 micro-amps,
verify correct gas supply and manifold pressures.
10.4 Special Service Issues - Premix
Combustion System
10.4.1 System Operation
Premix combustion systems are less tolerant of
fuel and air imbalance than other technologies. Fuel
gas properties, incorrect supply or manifold pressure
affect their operation and reliability. If fuel gas heat
content is low, combustion is "lean" and tends to be
unstable. Flames may lift off the burner, causing out-
age. If heat content is high, "rich" combustion results,
with low, hot flames that can overheat the burners.
Likewise, low gas supply or manifold pressure results
in lean, unstable combustion and high manifold pres-
sure results in a rich process and hot burners.
The air pressure inside the burner throat also
effects combustion. Incorrect air pressure will affect
performance and reliability of the heater. The burner
throat pressure should be adjusted to 1.0" W.C., see
Section 10.4.3
for adjustment procedures. If the air
pressure is too high, combustion will tend to be “lean”
and unstable. Flames may lift off the burners and be
extinguished. If air pressure is to low, the combus-
tion will be “rich”. The flames will be low and hot.
This could lead to burner overheating and failure. The
burner throat and gas manifold pressure need to be bal-
anced for stable combustion to occur.
The sealing of the combustion chamber and flue
assembly is also important to maintaining good com-
bustion. The combustion chamber of the LXi runs at a
slightly positive pressure (0.08" W.C. to 0.18" W.C.).
It is important that combustion products do not leak
from the combustion chamber or flue collector inside
the cabinet of the heater where they will be pulled into
the combustion air fan. Most of the oxygen in combus-
tion products has been consumed. If these combustion
products are pulled into the combustion air fan, it may
cause a rich combustion condition and that will lead to
a short yellow streaked flame that can decrease burner
life. Combustion chamber and flue collector sealing
must be maintained in “factory” condition. Service
operation involving burner, heat exchanger or fuel col-
lector removal must be conducted with this in mind.
10.4.2 Field Service and Adjustment
As with all gas-fired appliances, the first order of
business is to verify correct gas type, supply pressure,