Lochinvar EnergyRite ER152 - Manual (Page 18)

18
Service Manual
Combustion Air Shutter Adjustment
This pool heater uses a fan assisted combustion process. The fan
air shutter is factory preset and should not need adjusting in
most cases. If adjustment is required, the fan air shutter may be
manually adjusted to a dimension specified for each model (see
Table 2B).
Follow the steps below to adjust the fan air shutter if the pool
heater does not function properly or a continuous low air
condition is observed:
1. Check for proper installation and draft in the venting
system. Correct as required.
2. Remove the upper left access door (FIG. 2-6).
3. Turn the power switch to the “OFF” position.
4. Turn the gas valve switch to the “OFF” position.
5. Use a ruler to measure the distance from the base of
the fan to the end of the air shutter (FIG. 2-7).
Compare this distance to the specified “A” dimension
for the pool heater in Table 2B.
6. If the air shutter needs adjusting, locate the air shutter on
the left side of the fan assembly.
7. Slightly loosen the screws securing the fan assembly to the
metal base.
8. Move the air shutter towards the left of the fan assembly to
open the shutter and increase the air pressure. Move the air
shutter towards the right of the fan assembly to close the
shutter and decrease the air pressure.
9. Once the air shutter has been properly adjusted, retighten
the screws securing the fan assembly to the metal base.
10. To measure the front chamber pressure, turn all the gas
valve knobs and the manual gas cock to the “OFF” position.
11. Locate the air pressure switch on the left side panel. Trace
the hose from the air pressure switch to the chamber
pressure barb located in the top of the upper chamber.
Remove the hose from the chamber pressure barb and
connect the hose from the manometer or magnahelic to this
barb to measure the air pressure in the front chamber.
12. Turn the power switch to the “ON” position.
13. Set the thermostat to call for heat. The fan will start.
14. While the combustion air fan is running for the pre-purge
cycle and the pressure in the front chamber stabilizes,
compare this pressure to the chamber pressure specified in
Table 2B.
15. If adjustment is necessary follow steps 7 - 9 on how to
adjust the air shutter.
16. Turn the power switch to the “OFF” position.
17. Remove the manometer or magnahelic hose from the front
chamber barb and reinstall the hose from the air pressure
switch to the barb.
18. If the pressure switch still exhibits failures, check the
differential air pressure measurement.
Figure 2-6_Combustion Air Fan Location
2
Maintenance
"A"
Figure 2-7_Combustion Air Fan with Air Shutter “A”
Dimension
TABLE - 2B
AIR SHUTTER
ADJUSTMENT OPENING
Model
“A” Dimension
Opening
Chamber
Pressure
ER152 1 1/4" 1.4"
ER202 1 1/4" 1.4"
ER252 1 3/8" 1.4"
ER302 1 9/16" 1.4"
ER402 1 3/4" 1.4"