STA-RITE SR200NA Service Manual page 7

SECTION ONE – Heater Design and Function
Gas and Air Flow Through the Heater
Figure 1-5: Air and Gas Flow
1. The Blower draws ambient air into the Burner
System by negative pressure through the A A A A i i i i r r r r
O O O O r r r r i i i i f f f f i i i i c c c c e e e e .
2. The Blower at the same time is drawing Natural or
Propane Gas into the Burner System by negative
pressure through the G G G G a a a a s s s s O O O O r r r r i i i i f f f f i i i i c c c c e e e e .
3. The air and gas are thoroughly mixed in the M M M M i i i i x x x x i i i i n n n n g g g g
T T T T u u u u b b b b e e e e .
4. The B B B B l l l l o o o o w w w w e e e e r r r r then forces the air/gas mixture into the
F F F F l l l l a a a a m m m m e e e e H H H H o o o o l l l l d d d d e e e e r r r r in the C C C C o o o o m m m m b b b b u u u u s s s s t t t t i i i i o o o o n n n n C C C C h h h h a a a a m m m m b b b b e e e e r r r r under a
slight positive pressure.
5. The mixture is ignited in the C C C C o o o o m m m m b b b b u u u u s s s s t t t t i i i i o o o o n n n n
C C C C h h h h a a a a m m m m b b b b e e e e r r r r , around the circumference of the
F F F F l l l l a a a a m m m m e e e e h h h h o o o o l l l l d d d d e e e e r r r r . Combustion continues until the pre-
set water temperature is reached.
6. The H H H H e e e e a a a a t t t t E E E E x x x x c c c c h h h h a a a a n n n n g g g g e e e e r r r r tubes surrounding the
Burner/Flameholder extract heat from the hot flue
gases and heat the water flowing through the
tubes.
7. The cooled exhaust is collected in a sealed E E E E x x x x h h h h a a a a u u u u s s s s t t t t
P P P P l l l l e e e e n n n n u u u u m m m m , then is discharged out the V V V V e e e e n n n n t t t t B B B B o o o o d d d d y y y y .
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3
Air
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2
4
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S S S S a a a a f f f f e e e e t t t t y y y y P P P P r r r r e e e e c c c c a a a a u u u u t t t t i i i i o o o o n n n n s s s s : : : :
Risk of fire or explosion.
If Combination Gas Control Valve does not open or if
fuel does not ignite properly, DO NOT attempt to over-
ride safety interlocks to force combustion. Find and
fix fault before operating heater.
Exhaust
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