LAARS Mighty Max VW (Sizes 320M - 400M) - Installation, Operation and Maintenance Instructions - Manual (Page 26)

Page 26
LAARS Heating Systems
long as the ignition control igniter senses a stable
flame.
5. After the call for heat is satisfied the ignition
control closes the gas valves and operate the
blower for a thirty (30) second post purge cycle.
This clears the combustion chamber of
combustion products.
The ignition is attempted three times. If ignition
is not successful, the control shuts down and “locks
out”. It remains in the lockout condition until the
heater is turned off then back on or 120 Vac power to
the heater is interrupted.
5.2 Venturi and Gas Pressure
Regulator System
Field Checkout
See Section 3.2 “Venturi and Gas Pressure
Regulator System” for proper setup procedure.
5.3 Electrical Components
This section describes guidelines for checking
the operation of electrical components installed on the
heater. Refer to the wiring diagram for correct
connection locations.
5.3.1 General Troubleshooting
This section describes guidelines for checking
the electrical components of the heater. Experience
has shown that most complaints about heaters failing
to fire have nothing to do with the heater itself.
Usually, one of the protective switches in the heater
system has shut down operation.
Any of the following can prevent proper
operation. Check these items first:
1.
Be sure the heater has been properly installed
(see Section 2).
2. Make sure the pump is not airlocked, clogged or
otherwise inoperative.
3. Make sure the gas valve is on and there is
sufficient gas pressure in the line. All external
gas valves must be open.
WARNING
The ignition control and igniter operate on 120V
power. Keep this in mind while servicing the heater,
and take care to avoid contact with electrically live/
energized parts which will cause electrocution,
leading to property damage, injury or loss of life.
ATTENTION
Débranchez la chaudière avant d’enlever ou de
remplacer tout élément ou branchement de fil. Si la
chaudière est branchée, « connecter » la valve de
gaz ou mettre accidentellement à la terre le
faisceau de fils ou des terminaux au corps ou à la
gaine de la chaudière peut faire sauter le plomb (ou
disjoncteur) de la commande d’allumage.
4. Verify that the electrical circuit serving the boiler
is ON
5. Make sure the toggle switch on the right side of
the boiler is ON.
6. Check the fuse inside the black, twist-lock fuse
holder. If it is burned, replace it with a 2-amp
fuse (part number E0084400).
7. With the power off inspect all electrical
connections and wiring. Finding a loose
connection or charred wire can save a lot of time
and money.
8. Make sure the temperature controller is set high
enough to call for heat.
9. Make sure none of the manual reset controls, i.e.,
low water cutoff, high limit, etc., have tripped.
Reset any tripped switches
If the pump is circulating water and the
foregoing items check out okay, the trouble may be in
the boiler control system.
Caution: Disconnect power to the heater before
removing or replacing any component or wire
connection. If the power is not disconnected,
“jumping” the gas valve or accidentally grounding the
wire harness or component terminals to the heater
frame or jacket could cause the ignition control fuse to
blow.
Figure 20. Lower Front Panel Removal.
OUT OF
PRODUCTION