Reznor YDSA Unit Installation Manual - Manual (Page 39)

Form I-Y, P/N 273646R6, Page 39
FIGURE 23 - Manifolds with
Staged Control Option AG71
(2-stage control, single heat
section) and Option AG72
(4-stage control, dual heat
sections)
Flue
Collection
Box
Venter
Assembly
Single Heat Section
Manifold Assembly with
2-Stage Option AG71
Optional
Low Gas
Pressure
Switch
Optional
High Gas
Pressure
Switch
2-Stg
Gas
Valve Ignitor
Limit
Manifold Pressure Tap
Optional High Gas
Pressure Switch
Ignitor Limit
Venter
Assembly
Dual Heat Section
Manifold Assembly
with 4-Stage
Option AG72
Manifold Pressure Tap
Heat Section 2
Manifold Pressure Tap
Heat Section 1
Venter
Assembly
2-Stg
Valve
Optional
High Gas
Pressure
Switch
2-Stg
Valve
Optional Low
Gas Pressure
Switch
Ignitor
Limit
NOTE: The manifolds
illustrated are for standard
efficiency, non-condensing
heat sections. Follow the
same steps for measuring
manifold pressure on high
efficiency, condensing
heat sections.
Measuring Manifold Pressure
Measuring manifold gas pressure cannot be done until the heater is in operation. It is
a procedure step included in the “Checklist - Startup” steps, Paragraph 10.5.2. When
performing this Startup Step, select and follow the instructions that apply to the gas
control option on the unit.
• Two and Four Stage Options AG71 and AG72 (apply to Model YDSA only)
• Electronic Modulation Control Options AG73 and AG74 (apply to Models YDHA,
YDMA, and YDSA)
Gas pressure measurements should be done with a digital manometer. Two manom-
eters may be required.
IMPORTANT NOTES: On units with two heat sections, take gas pressure measure-
ments with both sections in operation.
Manifold pressure should be as shown in the table on page 49 for the model size, gas
type, and gas control option or as noted on the rating plate.
WARNING
Manifold pressure must never exceed the value listed in the
table on page 49 (or as shown on the rating plate).
9.2.2 Checking
Gas Pressure
(cont’d)
NOTE: If unsure of the
Gas Control Option Code
(AG71, AG72, AG73, or
AG74), check the wiring
diagram on the heater.
All option codes affected
by electrical power are
listed on the bottom of the
wiring diagram after the
unit Model and Size.