Replacement Valves
Table Of Contents
- SAFETY WARNINGS AND GUIDELINES FOR A QUALIFIED SERVICE TECHNICIAN
- Instructions for Selecting a Replacement Ignition Controller and/or Valve
- Serial Number and Model Codes
- Serial No. Decoding
- Serial Number Key - Month and Year of Manufacture
- Heater Serial No. PREFIX and SUFFIX Codes
- Model No. Decoding
- Safety Pilot or Ignition System Originally Supplied, Identified by Serial No. Code -- See Serial No. Decoding on pages 3-4. (N/A = Not available; see other notes below.)
- Type of Valve Originally Supplied -- See Serial No. Decoding on pages 3-4.
- Maxitrol Components for Electronic Modulation - Indirect-Fired Equipment Model Series X, SC, RG, RP, RX, RPV, and EEDU with Options AG7, AG8, AG9, AG21, AG39, AG40, AG41, or AG42
Form P-VALVES, P/N 263995, Page 21
42
AG57, 6:1 modulating gas control manifold, illustrations identifying valves by their
location.
To 2/3 Burner
To 1/3 Burner
Modulating
Gas Valve
Gas Valve controlling
gas flow to 2/3 burner
Size Gas P/N Code
100-300 Nat 196980 Z7
350-400 Nat 196981 Y3orZ8
Gas Valve controlling
gas flow to 1/3 burner
Size Gas P/N Code
100-400 Nat 196980 Z7
Two orifices
to full Burner
To 1/3
Burner
To 2/3
Burner
Modulating Gas Valve
SIZES 450-700
Gas Valve controlling
gas flow to 2/3 burner
Gas P/N Code
Nat 196981 Y3or Z8
SIZES 450-700
Gas Valve controlling gas flow to 1/3 burner
Gas P/N Code
Nat 196980 Z7
SIZES 450-700
Gas Valve controlling
gas flow to full burner
Gas P/N Code
Nat 196981 Y3 or Z8
Manifold
Arrangement
for Gas Control
AG57 on Gas Heat
Section Sizes
100-400
Manifold Arrangement
for Gas Control AG57
on Gas Heat Section
Sizes 450-700
To 2/3
Burner
To 1/3
Burner
Two orifices
to full Burner
STAGE 1
STAGE 3
STAGE 2
SIZES 450-700
Gas Valve controlling
gas flow to 2/3 burner
Gas P/N Code
Nat 196981 Y3or Z8
Pro 196983 Y5 or A1
SIZES 450-700
Gas Valve controlling
gas flow to full burner
Gas P/N Code
Nat 196981 Y3 or Z8
Pro 196983 Y5 or A1
SIZES 450-700
Gas Valve controlling gas flow to 1/3 burner
Gas P/N Code
Nat 196980 Z7
Pro 196982 Z9
Manifold Arrangement
for Gas Control AG55
on Gas Heat Section
Sizes 450- 700
43
Ball valve and actuator in
deep modulation Gas Control
Options AG70, AG58, and
D12G.
See manifold illustrations and
notes below.
AG70 Manifold in
MAPS
®
III Models RCDB/
RDDB & MAPS
®
IV Models
RCDC/RDDC with Heat
Section Sizes 100, 150,
and 200
Orifice
Adapter
Ball Valve
Optional High Gas
Pressure Switch
Transducer
Ball Valve
Actuator
Gas
Valve
Optional Low Gas
Pressure Switch
Manifold Pressure Tap
NOTE: P/N 255786 is ball valve
only; actuator is P/N 222862.
Orifice
Adapter
Orifice Adapter
Optional High Gas Pressure Switch
Transducer
Ball
Valve
Single-Stage
Gas Valve
Ball Valve
Actuator
Optional Low Gas
Pressure Switch
Manifold Pressure Tap
AG70 Manifold in
MAPS
®
III Models RCDB/
RDDB & MAPS
®
IV
Models RCDC/RDDC
with Heat Section Sizes
250 and 300
NOTE: P/N 258321 is
ball valve only; actuator
is P/N 222862.
NOTES (cont'd) for
pages 11-18, "Type
of Valve Originally
Supplied"