Maytag MDG31 Manual

Service Procedures
for the
Model MDG31,51,77 Dryer
Hot Surface Ignitor Gas
Part No. 450274
Maytag Co.
403WestFourthStreet North
Newton,Iowa 50208
[phone]

“IMPORTANT NOTE TO PURCHASER”
Information must be obtained from your local gas supplier on the
instructionstobefollowediftheusersmellsgas. Theseinstructions
mustbepostedinaprominentlocationnearthe dryer.
FOR YOUR SAFETY
Do not store or use gasoline
orotherflammablevapors
andliquidsinthevicinityof
thisoranyother appliance.
POUR VOTRE SÉCURITÉ
Ne pas entreposer ni utiliser d’essence
nid’autresvapeursouliquides
inflammablesàproximité de cet
appareiloude tout autre appareil.
Wehave tried to make this manual as complete aspossible andhope you will find it useful. The manufacturer
reserves the right to make changes from time to time, without notice or obligation, in prices, specifications,
colors, and material, and to change or discontinue models. The illustrations included in this manual may not
depict your particular dryer exactly.
IMPORTANT
For your convenience, log the following information:
DATEOFPURCHASE ______________________________________________ MODELNO. ____________________________
DISTRIBUTOR’S NAME ___________________________________________________________________________________
SERIAL NUMBER(S) ______________________________________________________________________________________
_______________________________________________________________________________________________________
_______________________________________________________________________________________________________
For replacement parts, contact the distributor from which the dryer was purchased or contact:
MAYTAG
403 West Fourth St. North
Newton,Iowa 50208
[phone]
Retain This Manual in a Safe Place for Future Reference
This product embodies advanced concepts in engineering, design, and safety. If this product is properly
maintained, it will provide many years of safe, efficient, and trouble free operation.
Only qualified technicians should service this equipment.
OBSERVE ALL SAFETY PRECAUTIONS displayed on the equipment or specified in the installation
manual included with the dryer.
The following “FOR YOUR SAFETY” caution must be posted near the dryer in a prominent location.
MDG31,51,77

Table of Contents
Part Locations and Removal ................4
LowerFrontPanel Removal ......................................... 4
UpperFrontPanel Removal ......................................... 4
TopCoverRemoval....................................................... 4
LintBox/BlowerAssemblyRemoval............................. 4
GasValve/Ignition SystemRemoval............................. 5
GasValve/Ignition System Components ...................... 6
OvenHousing Components.......................................... 6
TumblerSupport
WheelAssembly Replacement .................................... 6
TumblerAlignment ....................................................... 7
BeltReplacement ........................................................ 8
Placing the Belt ........................................................... 8
MDG31BeltReplacement ............................................ 9
Placing the Belt ........................................................... 9
Electrical Component Locations........10
Electrical Panel ......................................................... 10
Sail Switch andAxial ProbeAssembly ...................... 10
Exhaust Probe, Exhaust Hi-limit,
andLintDrawerSwitch ...............................................11
IMPORTANT
You must disconnect and lockout the electric
supply and the gas supply or the steam supply
before any covers or guards are removed from
the machine to allow access for cleaning,
adjusting,installation,ortestingofanyequipment
per OSHA (Occupational Safety and Health
Administration)standards.
Please observe all safety precautions
displayed on the equipment and/or specified in
theinstallationmanualincluded withthedryer.
CAUTION
Dryer(s)should never beleftunattendedwhile in
operation.
“Caution: Label all wires prior to disconnection
whenservicingcontrols. Wiringerrorscancause
improperoperation.”
«Attention: Lor des opérations d’entretien des
commandes étiqueter tous fils avant de les
déconnecter. Toute erreur decâblage peut étre
unesourcededanger et de panne.»
WARNING
Childrenshould notbeallowed toplayonor near
thedryer(s). Childrenshouldbesupervisedifnear
dryer(s)inoperation.
Under no circumstances should the dryer door
switch(es), lint door/drawer switch(es), or heat
safetycircuit(s)everbe disabled.
Thedryermustnever beoperatedwithanyof the
back guards, outer tops, or service panels
removed. Personalinjury or fire could result.
Thedryermustnever beoperatedwithoutthelint
filter/screen in place, even if an external lint
collectionsystemisused.
FOR YOUR SAFETY
Do not use dryer in the presence of dry
cleaningfumes.
The dryers must not be installed or stored in
an area where it will be exposed to water
and/orweather.
The wiring diagram for the dryer is located in
thefront electrical control box area.

4 MaytagCo. 450274-4
Part Locations and Removal
LOWER FRONT PANEL REMOVAL:
Remove the lint drawer. Remove the four screws
located just below the loading door. Tilt the top of
thepanel out andlift thepanel up andaway fromthe
dryer.
UPPER FRONT PANEL REMOVAL:
Remove the four screws located just above the top
loading door. Tilt the bottom of the panel out and lift
the panel up and away from the dryer.
Unplug two connections on the exhaust hi-limit at
the left of the lint box. Also disconnect the two
connectionsfor thelint drawerswitch, locatedat the
back of the lint box. The lint box may now be pulled
out through the front of the dryer.
Unplug the motor harness.
For MDG31, remove two screws above the lint
drawer. For MDG 51,77, also remove two screws
beneath the gasket on the left and right side of the
lint drawer. Also, unplug the exhaust temperature
probe.
LINT BOX/BLOWER ASSEMBLY REMOVAL:
TOP COVER REMOVAL:
Firstremovethe back guard,thefour screws holding
topcover. Next pull top cover toward the rear of the
dryer and lift up.
Tilt the bottom of the panel out and lift the panel up.
Align support rod into hole to support control panel.
Disconnect the electrical connections. Remove
screw from hinge to remove the control panel.
LINTDRAWER
SWITCH
EXHAUST
HI-LIMIT
For Models MDG31,51,77
For Models MDG31,51,77
For Models MDG31,51,77
SUPPORT
ROD
DOOR
SWITCH
For Models MDG31,51,77
SERVICE
SWITCH

450274-4 MaytagCo. 5
GAS VALVE/IGNITION SYSTEM REMOVAL:
Be sure to shut off the gas main and then proceed
to remove electrical connections and screws
indicated. Remove lower front panel. Disconnect
union and screws noted with arrows.
By removing the top screws you will be able to
remove the burner tube. After, removing the top
burner, without damaging the Hot Surface Ignitor,
remove the whole gas valve assembly. Be careful
during assembly not to damage the Hot Surface
Ignitor. Replace assembly in the reverse order.
Inspect all wires to be sure all lead directly toward
the front of the dryer. Be sure no wires are caught
on the burner tube or ignitor.
To remove motorized impellor assembly:
Remove the six hex nuts shown with arrows. Now
pulltheblowermotorassemblyapartfromtheblower
housing. Remove the four phillips screws shown
with arrows and separate the motorized impellor
from the blower motor mount.
To remove motorizedimpellor assembly, removelint
housing cover, lint screen, and the four screws
shown with arrows. Pull the motorized impellor
assembly out through the opening.
For Models MDG31,51,77
For Models MDG31,51,77
Gas Valve Ingnition System

6 MaytagCo. 450274-4
OVEN HOUSING COMPONENTS:
GAS VALVE/IGNITION SYSTEM COMPONENTS:
BURNERTUBE
IGNITOR
GAS VALVE
For Models MDG31,51,77
OVEN CHAMBER
RADIANT
SENSORS HOTSURFACE
IGNITOR
Dual Burner 51,77
RADIANTSENSOR
BURNER HIGH-LIMIT
GAS VALVE
HOTSURFACE
IGNITOR
TUMBLER SUPPORT
WHEEL ASSEMBLY REPLACEMENT:
The front wheel assemblies can be replaced with
the lower front panel removed. Remove the three
bolts by reaching upward with a socket or box
wrench. The illustration below is provided to show
the location of these wheels as the wheels cannot
easily be seen while standing in front of the dryer.
All wheel assemblies are mounted on slots to allow
foralignmentofthetumbler. Afteroneormorewheel
assemblies are replaced, the tumbler must be
realigned.
The left rear wheel assembly can be removed with
just the back guard removed. The rear right wheel
requires removing the back guard, heat duct, and
oven. Be sure to mark the position of rear wheel
brackets prior to removal (refer to photo right).
For Models MDG51,77
For Models MDG31

450274-4 MaytagCo. 7
Adjust the tumbler position by loosening the three
bolts and forcing the wheel assembly toward the
center of the dryer to raise the tumbler and to move
it away from the side. A large screwdriver can
provide the necessary leverage. Adjustment of the
front of the tumbler is made by equalizing the gap
onthetop,bottom,leftandright bymovingthewheel
assemblies.
TUMBLER ALIGNMENT:
Proper alignment is achieved by making the gap
between the tumbler and openings in the front and
rear bulkheads equal on all sides.
The front to bulkhead may be checked for accuracy
by using a thickness gauge. The rear gap is not
accessible. Marking the position of the rear wheel
brackets before removing the brackets will help in
replacing the tumbler back into it’s original position
when the wheel brackets are reinstalled.
Below, both wheel assemblies are adjusted correct
and spacing is even on all sides.
EXAMPLES:
Intheillustrationstothe right, both wheelassemblies
must be moved to the right in order to move the
tumbler right. The left wheel assembly must move
a little more than the right in order to lift the tumbler.

8 MaytagCo. 450274-4
BELT REPLACEMENT:
Shut off electrical power to the dryer. Lockout and
tagout supply voltages. Followthe stepsto remove
front middle panel. Next you will remove either the
front bottom or front upper panel, depending on
pocket you are working on. Remove the belt from
the motor sheave. Next, remove the two screws
fastening the lint coupe to the front panel. Remove
the front panel screws, while holding up the
basket. Tilt the top of the front panel forward. Take
note of position of motor adjustment nut. Spin
counterclockwise to loosen tension. The old belt
can now be removed. Slide the new belt around
basket and push belt to a position close the motor
sheave.
PLACING THE BELT:
Nowthatthebeltisclosetothemotorsheave(Fig.1),
make sure the motor pivot is at it’s highest point.
Wrap the belt under the motor sheave (Fig.2), then
push the belt over the idler wheel (Fig.3). Once this
has been accomplished make sure to spin the
basketbyhandtoself align the beltonmotorsheave
and idler wheel. Tighten the motor adjustment nut
to position previous set.
FIG. 1
FIG. 2
FIG. 3

450274-4 MaytagCo. 9
MDG31 BELT REPLACEMENT:
Shut off electrical power to the dryer. Lockout and
tagout supplyvoltages. Follow thesteps to remove
front middle panel. Next you will remove either the
front bottom or front upper panel, depending on
pocket you are working on. Remove the belt from
the motor sheave. Next, remove the two screws
fastening the lint coupe to the front panel. Remove
the front panel screws, while holding up the
basket. Tilt the top of the front panel forward. Take
note of position of motor adjustment nut spin
counterclockwise to loosen tension. The old belt
can now be removed. Slide the new belt around
basket and push belt to a position close the motor
sheave.
PLACING THE BELT
BACK ON THE MOTOR SHEAVE:
Placebeltinstallationtool(BIT-P/N319582)overbelt
(Fig. 1) and rotate in a clockwise direction. While
rotating run BIT under motor sheave (Fig. 2).
Continueto spin BIT,beltwill thenwrap under motor
sheave (Fig. 3). Remove BIT from dryer (Fig. 4).
Next,you want to rotate basket slowly toensure it is
on the sheave completely. Tighten the motor
adjustment nut to position previous set.
FIG. 1
FIG. 4
FIG. 2
FIG. 3

10 MaytagCo. 450274-4
Electrical Component Locations
SAIL SWITCH AND AXIAL PROBE ASSEMBLY:
Located behind back guard. Access doors are
provided. Backguard does nothave to beremoved.
ELECTRICAL PANEL:
Theelectricalpanelislocatedbehindthefrontmiddle
panel.
For Models MDG31
For Models MDG51,77
DOOR
SWITCH
COMPUTER
PANEL
COVER
ROTATIONAL
SENSOR
SWITCH
REVERSING
RELAY
COMPUTER
COVER
DOOR SWITCH
For Models MDG51,77
For Models MDG31
AXIAL
PROBE
SAIL
SWITCH
BURNER
HIGH LIMIT
AXIAL
PROBE
SAIL
SWITCH

450274-4 MaytagCo. 11
EXHAUST PROBE, EXHAUST HI-LIMIT,
AND LINT DRAWER SWITCH:
Temperature probe and exhaust hi-limit are
accessible without the lint box being removed. The
lint drawer switch can be removed after the lint box
is and the cover has been removed.
LINT DRAWER SWITCH
TEMPERATURE
PROBE
EXHAUST
HI-LIMIT
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Part No. 450274 4- 03/09/06 - 0