Market Forge M24G1A Service Manual

MODULAR

5033A

Printed in U.S.A.

4/75

Everett Ma.

02149

GAS
STEAM

SUPPLY
GENERATORS

Parts & Service
Manual

Area Code 617 387-4100

TABLE OF CONTENTS

5035

Subject Code No. Page
HOW TO USE THIS MANUAL 5023 3
BOILER STARTING INSTRUCTIONS 5023 3
170,000 BTU GAS BOILER - ASSEMBLY 5024 4
170 000 BTU GAS BOILER -PARTS LIST 5024 4
250,000 BTU GAS BOILER - ASSEMBLY 5026 5
250,000 BTU GAS BOILER - PARTS LIST 5026 5
LIGHTING INSTRUCTIONS 5028 6
ADJUSTING THE BURNERS 5028 6
CONTROL BOX ASSEMBLY - MANUAL BLOWDOWN 5150 7

CONTROL BOX.ASSEMBLY - AUTOMATIC BLOWDOWN 5151 8

WATER LEVEL CONTROL 5008 9
WATER LEVEL CONTROL ADJUSTMENTS 5009 10
SERVICING THE SOLENOID WATER FEEDERS 5009 10
PRESSURE REDUCING VALVE 5010 11

24 INCH CABINET 5011 12
36 INCH CABINET 5012 13

WIRING DIAGRAMS 5013 14
WIRING DIAGRAMS 5014 15

TROUBLE -SHOOTING GUIDE 5029 16
TROUBLE -SHOOTING GUIDE 5030 17
TROUBLE -SHOOTING GUIDE 5031 18
SETTING OF BOILER CONTROL PRESSURE SWITCHES 5032 19

COLD WATER CONDENSER ADJUSTMENT 5032 19

HOW TO USE THIS MANUAL

Market Forge, in the interest of both costs and efficiency to the purchasers of its equipment,
has designed these boilers with the latest type automatic controls in order to make it easier
for the operator to use and maintain this equipment. In addition, standard components are
utilized on all models of boiler equipment unless variances in size or capacity dictate a
divergence from this policy for more efficiency in operation. This parts and service manual is
written and illustrated to cover all boiler equipment that uses gas as a source of power other
than those which have been custom designed under special order.

The exploded view drawings of components are aids to the identification, disassembly and
assembly of parts. The parts listings provide information necessary for the ordering of
replacement parts (proper part names and part numbers). When requesting parts or service,
always furnish the model and serial number of your complete unit, which will indicate to
Market Forge Service Division the type of boiler with which you are equipped. This information
can be found on the nameplate attached to the boiler frame.

OPERATING INSTRUCTIONS FOR GAS BOILERS

Explanation of how the control system works on manual and automatic gas boilers. With the
boiler filled with water to its proper level and the fuel switch turned to its on position, the
solenoid in the gas valve will be activated allowing gas to flow to main burner which will be
ignited by the pilot. When the boiler builds up to its se t pressure, the pressure switch on the
left side of the control box opens. This will open up the circuit to the solenoid coil in the gas
valve which, in turn, will stop the flow of main gas to the burners. As the pressure in the
boiler drops off the pressure control switch will again come into operation and complete the
circuit and build the boiler back up to its set pressure. When the operator wishes to stop all
generation he need only to place the fuel switch to the off position.

5023

170,000 BTU GAS BOILER

AUTOMATIC BOILERS ONLY

30

SUPPLIED WHEN BOTH 5
&15STEAM SUPPLY IS NEEDED

McDONNELL MILLER

P

ROBE SYSTEM

MODEL: M24G1A or M36G1A

SPARE PARTS LIST GAS STEAM GENERATORS

170,000 BTU'S

ITEM QTY. PART NUMBER DESCRIPTION

1 1 10-1146 WATER GAUGE GLASS 51/2"

1 10-5869 WATER GAUGE GLASS 11"
2 1 10-4940 WATER GAUGE ASSY.
3 1 90 - 0039 RUBBER & BRASS WASHERS
4 1 10-2310 5/8" HEX NUT ( hand hole cover)
5 1 10-2414 5/8" WASHER ( hand hole cover )
6 1 90 - 5492 CHANNEL, YOKE ( hand hole cover )
7 1 10-2661 HAND HOLE GASKET
8 1 90 - 5495 HAND HOLE COVER
9 1 10-1135 DYNA - SEAL WASHER

10 1 10-2118 BOLT ( hand hole cover)

WATER LEVEL CONTROL ASSEMBLIES

WATTS

11 1 90 - 8929 COMPLETE FLOAT ASSEMBLY

2 10-5714 MICRO SWITCHES

1 10-5208 FLOAT BALL

1 10-5209 GASKET

1 90 - 5249 HEAD BELLOWS LINK & ROD ASSY.

1 91 - 5382 KIT, ADAPTOR - GASKETS

1 91 - 6222 HEAVY DUTY GASKET KIT

11 1 09 - 4887 REWORKED FLOAT ASSEMBLY

1 08-1409 GASKET, RING

8 09 - 3436 HX. HD.SCW.10-24 x 1/2" lg.

11 1 91 - 6287 KIT, FIELD REPLACEMENT, PROBES, PLATE & GASKET

1 91 -5112 KIT, FIELD REPLACEMENT, (3) PROBES, PLATE & GASKET

1 08 - 6328 LIQUID LEVEL CONTROL BD. ( 120 volt

1 08 - 6329 LIQUID LEVEL CONTROL BD. ( 240 volt)

1 08 - 6407 LIQUID LEVEL CONTROL BD. ( California Code )

1 08 - 6364 LIQUID LEVEL PROBE ( water fill )

1 08 - 6365 LIQUID LEVEL PROBE (low water level )

1 91 - 6286 PROBE PLATE, WELDED

1 08 - 4405 GASKET FOR PROBE PLATE

1 91 - 7031 PROBE PLATE, WELDED, ( 3 ) PROBES

1 08-4413 GASKET FOR PROBE PLATE # 91 - 7031

1 08 - 6398 LIQUID LEVEL PROBE, PRIMARY ( low water level )

1 08 - 6399 LIQUID LEVEL PROBE, SECONDARY ( low water level)

2 10-2515 LOCKWASHER, HELI - SPRING

2 10-8353 RUBBER BOOT FOR PROBES

4 09 - 3436 HX. HD. SCW. 10 - 24 x 1/2" lg.

12 1 10-4556 AIR VENT
13 1 10-4804 PRESSURE GAUGE
14 7 10-3250 BURNER
15 1 90 - 9429 LOWER DEFLECTOR PLATE ASSY.
16 1 90 - 9428 UPPER DEFLECTOR PLATE ASSY.
17 1 10-1043 GAS MANIFOLD
18 1 10-6472 GAS VALVE ( 120volt) NATURAL 3/4" inlet X 3/4" outlet

1 10-7683 GAS VALVE ( 120volt) PROPANE 3/4" inlet X 3/4" outlet

1 10-7684 GAS VALVE ( 240volt) NATURAL 3/4" inlet X 3/4" outlet

1 10-7685 GAS VALVE ( 240volt) PROPANE 3/4" inlet X 3/4" outlet

1 10-6465 GAS VALVE ( 120volt) NATURAL 1/2" inlet X 3/4" outlet

1 91-1337 DESCALER

MODEL: M24G1A or M36G1A

SPARE PARTS LIST GAS STEAM GENERATORS 170,000

BTU'S

ITEM QTY. PART NUMBER DESCRIPTION

1 10-6487 ADAPTER PLATE FOR PROPANE

19 7 10-2916 BURNER ORIFICE ( all btu's ) NATURAL

7 10-2921 BURNER ORIFICE ( all btu's ) PROPANE

20 1 10-5253 PILOT BURNER & ORIFICE ( natural )

1 10-5254 PILOT BURNER & ORIFICE ( propane )
1 91 -6154 PILOT BRACKET

21 1 90-1724 2" DRAIN LINE ASSY., AUTOMATIC

1 90-1832 2" DRAIN LINE ASSY., MANUAL OBSOLETE - NLA
22 1 10-5163 HAND BOX
23 1 95 - 3880 PILOT BURNER GAS LINE 24"

1 90 - 7948 PILOT BURNER GAS LINE 36"
24 1 10-6048 THERMOCOUPLE
25 1 90 - 5295 CONTROL BOX ASSY., MANUAL

1 90 - 5294 CONTROL BOX ASSY., AUTOMATIC
26 1 10-3661 DRAIN VALVE STD.
27 1 90-1724 2" DRAIN LINE ASSY., AUTOMATIC

1 90-1728 2" DRAIN LINE ASSY., AUTOMATIC
28 1 90 - 2823 SIDE COVER PLATES RIGHT & LEFT
29 1 90 - 2822 REAR COVER PLATES
30 1 10 -5787 1/2" SOLENOID ASCO DRAIN VALVE

1 10-1311 3/4" DRAIN VALVE

1 08 - 4872 COIL ONLY; FOR 3/4" DRAIN VALVE

1 10-3015 DRAIN VALVE REPAIR KIT ( new style )
31 1 10-1033 PRESSURE REDUCING VALVE
32 1 10-7955 15# SAFETY VALVE

1 10-4741 8# SAFETY VALVE ( 5# boilers only )

GAS VALVE - EXTENSION FOR PILOT PART NUMBERS

33 1 10-6467 ROD ADAPTER
34 1 10-1662 COTTER PIN
35 1 99-1310 GAS CONTROL KNOB
36 1 99-1313 EXTENSION ROD

MISCELLANEOUS

37 1 10-3489 3/4" 90 DEGREE OUTLET ELBOW
38 1 10-3490 3/4" 4 WAY TEE
39 1 10-2844 3/4" UNION

INSULATION

40 2 10-4095 MARONITE, SIDE INSULATION

BOILER SHELL, FLUE PARTS & MISELLANEOUS

1 90 - 9404 BOILER REPLACEMENT SHELL

1 90 - 9323 INNER FLUE

1 90 - 8849 OUTER FLUE ( RIGHT SIDE )

1 90 - 8850 OUTER FLUE ( LEFT SIDE )

1 90-1811 ACCEPTOR FOR FLUE

1 10-0880 GAS SOLENOID VALVE (120volt)

MODEL: M36G2A

WATER LEVEL CONTROL ASSEMBLIES

11 1 09 - 4887

REWORKED FLOAT ASSEMBLY

SPARE PARTS LIST GAS STEAM GENERATORS

250,000 BTU'S

ITEM QTY. PART NUMBER DESCRIPTION

1 1 10-4754 WATER GAUGE GLASS 6"

1 10-5869 WATER GAUGE GLASS 11"
2 1 10-4576 WATER GAUGE ASSY.
3 1 90 - 0039 RUBBER & BRASS WASHERS
4 1 10-2310 5/8" HEX NUT ( hand hole cover )
5 1 10-2414 5/8" WASHER ( hand hole cover )
6 1 90 - 5492 CHANNEL, YOKE ( hand hole cover )
7 1 10-2661 HAND HOLE GASKET
8 1 90 - 5495 HAND HOLE COVER
9 1 10-1135 DYNA - SEAL WASHER

10 1 10-2118 BOLT ( hand hole cover)

WATTS

11 1 90 - 8929 COMPLETE FLOAT ASSEMBLY

2 10-5714 MICRO SWITCHES

1 10-5208 FLOAT BALL

1 10-5209 GASKET

1 90 - 5249 HEAD BELLOWS LINK & ROD ASSY.

1 91 - 5382 KIT, ADAPTOR - GASKETS

1 91 - 6222 HEAVY DUTY GASKET KIT

McDONNELL MILLER

1 08-1409 GASKET, RING

8 09 - 3436 HX. HD.SCW.10-24 x 1/2" Ig.

PROBE SYSTEM

11 1 91 - 6287 KIT, FIELD REPLACEMENT, PROBES, PLATE & GASKET

1 91 -5112 KIT, FIELD REPLACEMENT, (3) PROBES, PLATE & GASKET

1 08 - 6328 LIQUID LEVEL CONTROL BD. (120 volt)

1 08 - 6329 LIQUID LEVEL CONTROL BD. ( 240 volt)

1 08 - 6407 LIQUID LEVEL CONTROL BD. ( California Code )

1 08 - 6364 LIQUID LEVEL PROBE ( water fill )

1 08 - 6365 LIQUID LEVEL PROBE (low water level)

1 91 - 6286 PROBE PLATE, WELDED

1 08 - 4405 GASKET FOR PROBE PLATE

1 91 - 7031 PROBE PLATE, WELDED, ( 3 ) PROBES

1 08-4413 GASKET FOR PROBE PLATE # 91 - 7031

1 08 - 6398 LIQUID LEVEL PROBE, PRIMARY (low water level )

1 08 - 6399 LIQUID LEVEL PROBE, SECONDARY (low water level)

2 10-2515 LOCKWASHER, HELI - SPRING

2 10-8353 RUBBER BOOT FOR PROBES

4 09 - 3436 HX. HD. SCW. 10 - 24 x 1/2" Ig.

12 1 10-4556 AIR VENT
13 1 10-4804 PRESSURE GAUGE
14 7 10-2940 BURNER
15 1 90 - 2830 LOWER DEFLECTOR PLATE ASSY.
16 1 90 - 2829 UPPER DEFLECTOR PLATE ASSY.
17 1 10-1060 GAS MANIFOLD

PARTS THAT ARE NOT SHOWN

MODEL: M36G2A

SPARE PARTS LIST GAS STEAM GENERATORS

250,000 BTU'S

ITEM QTY. PART NUMBER DESCRIPTION

18 1 10-6472 GAS VALVE ( 120volt) NATURAL 3/4" inlet X 3/4" outlet

1 10 -7683 GAS VALVE ( 120volt) PROPANE 3/4" inlet X 3/4" outlet
1 10 -7684 GAS VALVE ( 240volt) NATURAL 3/4" inlet X 3/4" outlet
1 10-7685 GAS VALVE ( 240volt) PROPANE 3/4" inlet X 3/4" outlet
1 10-6465 GAS VALVE ( 120volt) NATURAL 1/2" inlet X 3/4" outlet

19 7 10-2916 BURNER ORIFICE ( all btu's ) NATURAL

7 10-2921 BURNER ORIFICE ( all btu's ) PROPANE

20 1 10-5253 PILOT BURNER & ORIFICE ( natural )

1 10-5254 PILOT BURNER & ORIFICE ( propane )
1 91 - 3696 PILOT BRACKET

21 1 90-1724 2" DRAIN LINE ASSY., AUTOMATIC

1 90-1834 2" DRAIN LINE ASSY., MANUAL
22 1 10 -5163 HAND BOX
23 1 90 - 7888 PILOT BURNER GAS LINE
24 1 10-6048 THERMOCOUPLE
25 1 90 - 5295 CONTROL BOX ASSY., MANUAL

1 90 - 5294 CONTROL BOX ASSY., AUTOMATIC
26 1 10-3661 DRAIN VALVE STD.
27 1 10-7955 15# SAFETY VALVE

1 10-4741 8# SAFETY VALVE ( 5# boilers only )
28 1 90 - 2823 SIDE COVER PLATES RIGHT & LEFT

29 1 90 - 2822 REAR COVER PLATES
30 1 10-5787 1/2" SOLENOID ASCO DRAIN VALVE

1 10-1311 3/4" DRAIN VALVE

1 08 - 4872 COIL ONLY; 3/4" DRAIN VALVE

1 10 -3015 DRAIN VALVE REPAIR KIT ( new style )
31 1 10-1033 PRESSURE REDUCING VALVE

GAS VALVE - EXTENSION FOR PILOT PART NUMBERS
32 1 10-6467 ROD ADAPTER
33 1 10-1662 COTTER PIN
34 1 99-1310 GAS CONTROL KNOB
35 1 99-1313 EXTENSION ROD

MISCELLANEOUS
36 1 10-3489 3/4" 90 DEGREE OUTLET ELBOW
37 1 10-3490 3/4" 4 WAY TEE
38 1 10-2844 3/4" UNION

INSULATION
39 2 10 -4065 MARONITE, SIDE INSULATION
40 1 10-4068 MARONITE, REAR INSULATION

BOILER SHELL, FLUE PARTS & MISELLANEOUS

1 90-2817 BOILER REPLACEMENT SHELL
1 90 - 4525 INNER FLUE
1 90 - 8849 OUTER FLUE ( RIGHT SIDE )
1 90 - 8850 OUTER FLUE ( LEFT SIDE )
1 90 - 8066 ACCEPTOR FOR FLUE
1 91-1337 DESCALER