LAARS Mighty Therm VW (Sizes 2000-5000) - Installation, Operation and Maintenance Instructions - Manual (Page 16)

LAARS Heating Systems
Page 16
A. Combustion air supply to
heater room is
inadequate.
B. Stack or vent is blocked
or restrictive.
C. Severe down draft is
causing spillage of flue
products into room.
D. Gas pressure to burners
is excessive.
E. Heater not fitted for the
fuel being supplied.
F. Heater installed at high
altitude without proper
derating.
A. Check air supply opening.
Look for debris in screen or
louvre which covers
combustion air opening, or
for material blocking the
opening.
B. Look for blocked stack and
excessive number of elbows
in stack or excessive length
of horizontal runs.
C. Check for (1) proper vent
cap on stack; (2) adequate
height of stack above roof;
(3) equipment exhausting
air from inside of building;
and (4) proper installation
of draft diverter.
D. Check gas pressure with
manometer, and adjust with
heater firing at full rate.
E. See nameplate for correct
fuel.
F. Installations at altitudes in
excess of 2000 ft. above
sea level are subject to
jurisdiction of the local
inspection authorities.
A. If heater is used with an
air conditioning system,
chilled water may be
flowing either by gravity
or pressure through
boiler and creating
condensate on boiler
tubes.
B. Tube in heat exchanger
has overheated and
ruptured.
Possible Cause What To Do
Possible Cause What To Do
6. Soot in flueways or in tubes, or noxious fumes
indicative or bad combustion. SECTION 6.
Conversion of VW from Indoor
to Outdoor Models
Please read the following instructions with
Figure 16.
Figure 17 shows the conversion completed.
Please follow the instructions in their numerical
order, failure to do this will cause problems on
assembly.
6.1 Conversion Procedure
6.1.1 SECTION I: (See Figure 16)
1. Remove top panel. (1)
2. Remove front and rear upper panels. (2)
3. Remove front and rear wings LH & RH. (3)
4. Remove diverter assembly. (4)
5. Remove outer screw from upper end panel at
junction with lower end panel.
6. Remove and disconnect all probes and wires
going to castings and gas train.
7. Remove control box assembly - front of heater
(not shown).
6.1.2 SECTION II: (See Figure 17)
1. Install front LH & RH extension panels (flush
with top of upper end panel). (18)
2. Install rear LH & RH extension panels (flush
with top of upper end panel). (15) (pick up holes
provided into LB upper and lower end panels)
3. Install front bottom panel. (21)
4. Install rear bottom panel. (14)
5. Install front inner baffles (2) 4" from ends. (17)
6. Install rear inner baffle (1) 2" from ends. (16)
7. Install front LH & RH upper spacers. (27)
8. Install rear LH & RH upper spacers. (7)
9. Install front flue collector extension (screw onto
flange of lower flue collector only). (28)
10. Install rear flue collector extension (screw onto
flange of lower flue collector only). (8)
11. Install rear upper panel and remaining screws
from flue collector extension. (12)
12. Install middle rear panel. (13)
7. Water dripping in firebox.
A. Install flow-check valve or
programmed bypass valve
in the system for change-
over from heating to
cooling.
B. A tube failure always
caused by (a) scale
formation in the tube
or
(b) inadequate water flow
through the boiler.