Midco RS40 User Manual

direct spark ignition conversion burner is adaptable to any type gas utilization equipment,

including gravity and forced circulation furnaces and boilers, and is particularly recommended for horizontal and downdraft

Do not store or use gasoline or other

flammable vapors and liquids in the

vicinity of this or any other

Installation and service must be

performed by a qualified installer,

phone. Follow the gas suppliers'

supplier, call the fire department.

USER: Retain this manual for future reference. If other than routine service or maintenance

ATTEMPT REPAIRS. An inadvertent service error could result in a dangerous condition.

: The following terms are used to identify hazards, safety precautions or special

notations and have standard meanings throughout this manual. When you see the safety alert symbol and one of the

Identifies unsafe practices which would result in minor personal injury or product and property damage.

Installation and Service Instructions

602

8471 09

Printed in U.S.A.

Economite RS40

Conversion Burners

The ECONOMITE Model RS40
gas utilization equipment since it needs no draft to maintain a pilot. Power burner design makes it perfectly suited for oil

burner replacement.

In the United States, installation must conform with local

codes or, in the absence of local codes, with Installation of
Domestic Gas Conversion Burners , ANSI Z21.8a-latest
edition and National Fuel Gas Code, ANSI Z223.1-latest
edition(s) available from American National Standard
Institute. Further reference should be made to the
recommendation of your fuel supplier.

Note: Any additions, changes or conversions required in order

for the gas utilization equipment to satisfactorily meet the
application needs must be made by a MIDCO distributor (or
other qualified agency) using factory specified and approved
parts.

In Canada, installation must conform with local codes or, in the

absence of local codes, with Installation Codes for Gas

Burning Appliances and Equipment, CGA Standard
CAN/CGA 1-B149.1 or 2. When the conversion burner is

used on Forced Air Central Furnace, the two yellow and
black warning labels in the literature envelope shall be
attached in accordance with Installation Code, CGA
Standard CAN/CGA 1-B149, Clause 5.4.4.4. Further
reference should be made to the recommendation of your fuel
supplier.

WARNING: If the information in
these instructions is not followed
exactly, a fire or explosion may
result, causing property damage,
personal injury or death.

appliance.

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical
switch; do not use any phone in
your building.

• Immediately call your gas
supplier from a neighbor's

INSTALLER: Inform and demonstrate to the user

the correct operation and maintenance of this gas
utilization equipment. Inform the user of the
hazards of storing flammable liquids and vapors in
the vicinity of this gas utilization equipment and
remove such hazards. Affix this manual adjacent

to the conversion burner.
CODE COMPLIANCE IS THE SOLE RESPONSIBILITY
OF THE INSTALLER.

instructions.

• If you cannot reach your gas

service agency or the gas supplier.

as described in this manual is required, contact a qualified service agency. DO NOT

safety information terms as shown below, be aware of the hazard potential.

DANGER: Identifies the most serious hazards which will result in severe personal injury or death.
WARNING: Signifies a hazard that could result in personal injury or death.
CAUTION:

Midco®International Inc
4140 West Victoria Street Chicago, Illinois 60646
tel [phone] fax [phone] web www.midco-intl.com

Part 1 Installation

Specifications

NATURAL or PROPANE Gas

Air Delivery

(Approximate air delivery at zero draft)
Maximum Firing Rate**
Minimum Firing Rate**
Tube Diameter
Tube Length
Minimum Combustion Chamber Size

200 MBH

150 MBH
Gas Pressure Required

NATURAL or PROPANE
Electrical Supply
Flame Safety

Main Automatic Valve

Notes:

* SCFM=Standard Cubic Feet/Minute
** Ratings based on 1,000 BTU/cu. ft. NATURAL, 2500 BTU/cu. ft. PROPANE at Sea Level.
*** 1 MBH=1,000 BTU/Hr.
One gallon of fuel oil=140,000 BTU.
Derate burner for altitudes over 2,000 feet by 4% for each 1,000 feet above sea level.

24V Electronic Flame Safety, Direct Spark Ignition

with 100% shut-off, 30-second prepurge.

7" W x 11" L or 10" dia.

6" W x 10" L or 9" dia.

3 Function Redundant

42 SCFM*

200 MBH***

75 MBH***

4 inches

6.5 inches

5.0" to 14.0" W.C.
120/1/60, 3 Amp

Part 1 Installation

I Ventilation

CAUTION: The ECONOMITE RS40 is not intended for outdoor installation and must be
protected from excessive moisture. Provide adequate clearance for service and proper opera­tion.

_____________________________________

If the former automatic oil burner gave trouble-free operation, it is probable that the gas utiliza­tion equipment area has sufficient infiltration of air for combustion and dilution of flue gases.

Nevertheless, the area must be checked:

?? Open basement or utility areas of normal construction, without storm windows or tight
doors, will generally allow sufficient air infiltration. However, if the gas utilization equipment is
located in a tight or separate room, ventilation to an open area as described above will be
required. Install two permanently open grills, each sized on the basis of one square inch free
area per 1,000 BTU (but not less than 100 square inches) of the total input rating of all gas
utilization equipment in the confined space. One grille should be located within 12 inches of
the ceiling, the other within 12 inches of the floor.
?? If the gas utilization equipment is located in an area of unusually tight construction, or if
an exhaust fan, kitchen ventilation system, clothes dryer and/or fireplace is installed in the
building, provision must be made for an outside air supply near the gas utilization equipment
area. Install permanently open grills sized at not less than one square inch free area per 4,000
BTU of burner input. When ventilating through horizontal ducts, grills should be sized at not
less than one square inch free area per 2,000 BTU of all gas utilization equipment in the
confined space. In any case, the minimum dimension of rectangular air ducts shall not be less
than 3 inches.
?? In Canada, for detailed ventilation requirements, refer to standard CAN/CGA 1-B149.1 or
.2 and/or local codes.

_____________________________________

II Preparation of the Gas

Utilization Equipment

2

?? Clean the gas utilization equipment, heat exchanger interior, combustion chamber, and
flue connections. Remove all adhering tars, scale, dirt and soot. Inspect for actual leaks
and/or potential leaks.
?? Cement all joints, including those in the gas utilization equipment base and around door
frames, to prevent leakage into or out of the combustion chamber.
?? The access or firing door should open easily to relieve pressure. If positive latches exist,
they should be modified to permit easy opening; a spring loaded door holder is recommended.
?? On all boilers, make certain the pressure relief safety valve is in good operating condition.

_____________________________________

3

Part 1

Part 1 Installation

Installation Continued

III Combustion Chamber

A combustion chamber liner is normally required
to protect non-heat transfer surfaces and to
provide a radiant bed for rapid heat transfer to
the primary surfaces of the heat exchanger. In
most cases, an existing oil burner combustion
chamber liner can be used, if in good condition.
?? In the case of wet base boilers, where the
entire combustion chamber is comprised of heat
exchange surfaces and no combustion chamber
liner was provided for oil firing, a liner is usually
not required for the ECONOMITE. However, a

Figure 1: Dry Base Boiler with

Combustion Chamber Liner (Warm Air

Furnace Construction is Similar)

Figure 2: Wet Base Boiler with

Combustion Chamber Unlined

?? Before permanently setting the burner in place, check that the burner nozzle is free of
foreign materials and also that the electrodes have not been damaged or displaced, see
Figure 7.

_____________________________________

liner or target wall may be necessary if the
combustion chamber is unusually short, in order
to avoid flame contact on the heat exchanger
walls or flueways.
?? If a built up chamber liner is required, use
2300°F minimum insulating material.
?? The burner tube, must be sealed air tight
into the combustion chamber liner opening with
refractory material as shown by Figures 1 and 2.

CAUTION: In no case should the burner
tube be allowed to extend into the chamber
proper; it must be set flush with the inside
surface.

WARNING: Burner cabinet must be
mounted in orientation shown in Figures 1
and 2. Any other mountings may cause a
dangerous condition, and will void burner
warranty and agency approvals. Non-stan­dard arrangements may be available for
some models; consult factory for details if
required.

IV Chimney, Vent Connector,

and Draft Control

WARNING: The chimney shall be inspected for unsafe conditions such as
deteriorated masonry and excessive soot or other blockage or potential blockage.
Installation must conform with local codes or in the absence of local codes with
ANSI Z21.8b latest edition and NFPA, ANSI Z223.1 latest edition.

WARNING: The Vent Connector shall not be connected to a chimney already
venting solid fuel burning equipment, an incinerator or an open fireplace.

?? The Vent Connector shall be made of non-combustible, corrosion resistant material
capable of withstanding the vent gas temperature produced by the gas utilization
equipment and of sufficient thickness to withstand physical damage.
?? The Vent Connector shall be as short as possible. The entire length shall be readily
accessible for inspection, cleaning and replacement.
?? The length of horizontal uninsulated Vent Connector between chimney and a single
gas utilization equipment shall not exceed 75% of the height of the chimney above the con -

Maximum

Input

100 MBH
130 MBH
195 MBH
200 MBH

Table 1: Recommended Vent

Connector Sizes

Source: ANSI Z21.8b 1993, Installation

of Domestic Gas Conversion Burners.

For other applications,

consult appropriate standards.

Vent Connector

Dia.

5"
6"
7"
8"

nector, or 100% if the Vent Connector is insulated.
?? The Vent Connector shall be installed so as to
avoid turns or other construction features which
create excessive resistance to flow of vent gas. It
shall be installed without any dips or sags and shall
slope upward at least 1/4" per foot.
?? A manually operated damper shall not be
placed in the Vent Connector or chimney of any gas
utilization equipment.
?? The Vent Connector shall be firmly attached to
draft hood outlets and flue collars. Joints between
sections of connector piping shall be fastened by
sheet-metal screws or other approved means. The
Vent Connector shall be supported for the design

Part 1 Installation

Part 1

Installation Continued

IV Chimney, Vent Connector,

and Draft Control Continued

Figure 3: Draft Hoods Figure 4: Location for Barometric

Draft Regulator

Figures 3 and 4: Copyright by the American Gas Association. Used by permission of the copyright holder.

and weight of the material employed to maintain clearance and prevent physical damage
and separation of joints.
?? A draft hood or barometric draft regulator shall be installed in the same room or enclo­sure as the equipment in such a manner as to prevent any difference in the pressure
between the hood or regulator and the combustion air supply. In no case shall the relief
opening of the draft hood or barometric draft regulator be located at a point lower than the
top of the highest flue passage in the equipment.

_____________________________________

V Electrical

4

CAUTION: Do not add any power consuming devices in the low voltage circuit
as overloading of the transformer can result. Do not use Motor Relay to operate any
external devices as overloading of motor relay contacts can result.

Note: If any of the original wiring as supplied with the conversion burner must be replaced,
it must be replaced with type TFF wire or its equivalent.
Installation wiring and grounding of the burner must conform to local codes, or in their
absence in the United States to National Electric Code, ANSI/NFPA No. 70-latest

edition; in Canada, to Canadian Electrical Code Part 1, CSA Standard C22.1.

Figure 5: Wiring Diagram

?? Use 14 gauge copper wire for line voltage wiring. Be sure to hook up to a permanently
live circuit. Provide a fused on-off disconnect switch carrying a minimum 3 amp fuse.
?? The frame of the burner must be well grounded. A terminal is provided in the control
box for positive grounding where insulated pipe couplings are used or where any doubt
exists regarding grounding sufficiency.
?? Confirm that the polarity is correct—hot wire to black wire, neutral to white, and that
the neutral line is not subject to induced low voltage (check white wire to earth ground)
from other equipment as that can cause the electronic flame safeguard to malfunction.
?? Each installation must include suitable limit controls. Existing oil burner combination
limit and operating controls are normally NOT SUITABLE for gas burner use.

5

Part 1 Installation

Part 1

Installation Continued

V Electrical Continued

?? Set the thermostat heat anticipator for the total current draw handled by the
thermostat. The current draw of the ECONOMITE 24V operating circuit is 0.9 amps.

CAUTION: Label all wires prior to disconnection when servicing controls. Wiring
errors can cause improper and dangerous operation. Verify proper operation after
servicing.

_____________________________________

VI Piping

CAUTION: The available gas
pressure should be within the
limits shown in the SPECIFICA­TIONS section. Excessive pres­sure will damage Combination
Valve and Regulator. If the supply
pressure exceeds the 14.0" W.C.
maximum, a suitable intermediate
main regulator must be installed
ahead of the Main Manual
Shut-Off Valve shown in Figure 6.

?? The burner gas supply piping
should branch off from the main line
as close to the gas meter as possible.
Do not connect to the bottom of a
horizontal section. Use new black pipe

Figure 6: Piping Connections

and malleable fittings free of cutting
and threading burrs or defects.
?? Provide a sediment trap, union
and 1/8" pressure tap in piping close
to burner as shown in Figure 6.
?? Use pipe joint compound
approved for use with Liquid
Petroleum Gases.
?? Piping must comply with local
codes.
?? To obtain the maximum firing
rate of 200 MBH, the NATURAL and
PROPANE gas supply piping must
be sized to provide minimum of

5.0" W.C. pressure to the inlet of
the Combination Valve when the
burner and all other gas utilization
equipment are on.

Pipe

Size

1

/

2

3

/

4

1

11/

4

Type

of Gas

NATURAL

PROPANE

NATURAL

PROPANE

NATURAL

PROPANE

NATURAL

Table 2: Supply Pipe Capacities in MBH

Capacities shown are for a total pressure drop of

0.3" W.C. For higher permissible pressure drops,
consult your fuel supplier.

Source: Gas Engineering Handbook 1974

Approx. Capacity-MBH

Length of Pipe (ft.)

10

130
200

200

20 40 60

90

145
190

200
200

100
130

200
200

80

105
165
195
200

?? When pressure testing the
supply piping, the burner valve train must be protected. If the test pressure is 0.5 PSIG or less,
closing the Main Manual Shut-Off Valve will suffice.

CAUTION: If the test pressure is 0.5 PSIG or less, closing the Main Manual Shut-Off

Valve will suffice.

DANGER: Explosion hazard.

Do not use oxygen for pressure testing.

An explosion could occur during initial start-up.

100

80
125
150
200
200

VII Main Gas Spud

?? If the burner piping must be rearranged because of space limitations, be sure to carry
out the general arrangement shown in Figure 6. Install the Combination Valve in any
position except up-side down.
?? When the burner is installed in jacketed equipment, it is recommended that the
Combination Valve be left adjacent to the burner within the vestibule and the Main Manual
Shut-Off Valve be installed outside.

_____________________________________

Standard burners are approved for use with NATURAL or PROPANE gas only, and should
be used only with the gas specified on rating plate.
?? A Standard Model RS40 Economite is shipped ready for NATURAL gas. It is field
convertible to PROPANE gas, see Table 3.

Part 1

Part 1 Installation

Installation Continued

VII Main Gas Spud

Continued

?? As shipped, the installed
NATURAL gas spud has a .266"
diameter orifice size for an input
capacity range of approximately
150 to 200 MBH. Spare spuds
are included in a spare spud
bag (stamped with inch
diameter) for other capacity
ranges and/or conversion to
PROPANE, see Table 3.
?? The Combination Valve
Gas Pressure Regulator is set
to provide 2.0" W.C. manifold
gas pressure for minimum spud
input and the combustion air

*Main Gas Spud Orifice Size, approximate Manifold Pressure

setting as shipped. Data shown is approximate and based

on "0" overfire pressure at sea level

Table 3: Main Gas Spud Capacity and

Preliminary Gas and Air Settings

the PROPANE label from the spare spud bag over the NAT designation on the rating plate
and install the appropriate size main spud as detailed below.
?? If the required firing rate does not fall within the range of the installed spud, or if con­verting to PROPANE gas, select the correct capacity range from Table 3 and if so indicated,
the spud with the correct orifice size (stamped with inch diameter) from the spare spud bag.
If the required firing rate is at the minimum of a capacity range, select the next lower range
spud.
?? To change the main spud, turn off the Main Manual Shut-Off Valve and burner power,
remove the backplate, disconnect the field installed union located between Combination
Valve and Main Manual Shut-Off Valve and remove manifold assembly. Remove Nozzle
Assembly from Main Gas Spud, see Figure 7.Unscrew the installed main spud from the
manifold pipe and install the selected main spud. Reassemble burner in reverse order.

WARNING: Reposition the combustion air shutter for the maximum firing rate of

the selected spud capacity range. Do not change the Combination Valve Main Gas

Pressure Regulator setting at this time.

CAUTION: The approximate air and gas settings described above are for initial
start-up only. Final settings must be made in accordance with Section VIII, Initial
StartUp/Adjustment Instructions for adjustment of the manifold gas pressure are
detailed in Section XI, Combination Gas Valve.

_____________________________________

shutter is set for maximum spud
input, to provide a lean gas/air
mixture for initial start up.
?? If a standard NATURAL gas
ECONOMITE RS40 is to be
used with PROPANE gas, affix

VIII Initial

StartUp/Adjustment

6

WARNING: Ignition is automatic. Make spark observations into combustion
chamber only with Main Manual Shut-Off Valve closed. Confirm that gas utilization
equipment does not contain any accumulated gases. Purge as described in Step 3
below.

1. Check the burner piping and valves for gas leaks by applying a weak liquid soap
solution to unions and joints with the gas supply on. Leakage will be indicated by the
appearance of soap bubbles. Locate and correct all gas leaks before proceeding.

WARNING: DO NOT USE OPEN FLAME FOR CHECKING.

2. Purging the air from the gas supply line at this step will expedite the first light-off.

CAUTION: Purge gas to outside the building. Do not purge into the gas

utilization equipment.

3. To purge the gas utilization equipment and chimney of any accumulated gases, turn
Manual Gas Cock Knob on the Combination Valve to OFF, turn burner power on and set
the operating control to ON or thermostat to call for heat. Let the blower run long enough to
accomplish four air changes, but not less than five minutes.

4. CAUTION: Make sure that the capacity range of the installed spud and the
preliminary combustion air shutter setting are suitable for capacity rating of the gas
utilization equipment. Refer to Section VII, Main Gas Spud and Table 3.

5. RESET the Electronic Control by setting the operating control to OFF or the thermostat
below room temperature for at least 30 seconds, see Section XII, Electronic Control.

6. Confirm that Main Manual Shut-Off Valve is open. Turn Manual Gas Cock Knob on
Combination Valve to ON.

7

Part 1 Installation

Part 1

Installation Continued

VIII Initial Start-up/

Adjustment Continued

7. Turn operating control to ON or set thermostat above room temperature. Main flame
should come on after a 30 second pre-purge. Whenever the burner fails to light during the
6-second ignition trial, or if the flame is lost during the burner run and not re-established
within 36 seconds, the Electronic Control will shut off the Combination Valve and LOCK
OUT. To RESET the Control for restart, de-energize the Electronic Control by setting the
operating control to OFF or thermostat below room temperature for at least 30 seconds. If
burner still fails to light, turn it off and repeat from Step 5 above. Then if necessary, refer to
the Trouble Chart to isolate the problem.

WARNING: Repeated unsuccessful attempts to light will result in accumulated
gases in gas utilization equipment and chimney. To prevent these gases from reach­ing an explosive level, periodically purge the gas utilization equipment and chimney
as described in Step 3.

8. To make a preliminary setting of the burner input, determine the manifold gas pressure
required from Table 3 and adjust the Combination Valve Pressure Regulator accordingly,
see Section XI, Combination Gas Valve.

9. To determine the firing rate for NATURAL gas, accurately time test dial for the number
of seconds for one revolution and use the following formula. Turn off all other gas utilization
equipment.

3600 x test dial size x BTU value

No. of seconds for one rev. test dial.

Then divide by 1,000 for MBH value:

= BTU/Hr.

Example:

For PROPANE gas, consult your supplier for method of determining firing rate.

10. Readjust the combustion air shutter to provide a quiet, soft blue flame with well defined
orange and yellow tips for NATURAL gas or with well defined yellow tips for PROPANE.

11. Check the operation of the burner; start and stop it several times with the thermostat or
operating control.

12. With the burner running, check the operation of all limit and associated controls.

13. PERFORM THE FOLLOWING FINAL ADJUSTMENTS for combustion and flue gas

temperature. Take the flue gas samples and temperature immediately ahead of the draft
control.

A. The flue gas temperature should be above 325°F but not exceeding 550°F.

Excessive flue gas temperatures will result in low efficiencies. Low flue gas
temperature may cause excessive condensation. Reset gas input if necessary to
adjust stack temperature.

B. Make the final setting of the combustion air shutter by checking the flue gases with

an ORSAT or similar combustion testing instrument. The carbon monoxide content
should conform to local codes, or in their absence to the level specified in the
United States or Canadian Standard referenced on the front cover of this manual;
and the carbon dioxide content should be approximately 9.5% for NATURAL and

12.1% for PROPANE, or within the limits prescribed by local codes.

14. Check the draft control to make sure there is no spillage of flue products into the room.

15. FILL OUT THE INSTALLATION ADJUSTMENT DATA TAG and affix to the burner or

gas utilization equipment.

Note: For subsequent normal starting and shut-off procedure, refer to CONSUMER

INSTRUCTIONS or to the instruction plate mounted on the burner.

3600 x 1 x 1000

20

= 180,000 BTU/Hr. = 180 MBH

_____________________________________

Part 2 Service

Part 2 Service

IX Nozzle and Electrodes

DANGER: Be sure that the Main Manual Shut-Off Valve, Combination Valve and

Burner Power Switch are turned off before removing any parts for service.

WARNING: Do not attempt to FIRE the burner with the burner backplate removed
as air from the blower will not reach the combustion chamber and a dangerous level
of unburned gas could accumulate.

Figure 7: Nozzle Assembly and Electrode Assembly

The nozzle and electrode assembly can be removed as a unit by disconnecting the field
installed union located between Combination Valve and Inlet piping and disconnecting
electrode leads. Withdraw nozzle assembly completely by removing the backplate.
?? Service will normally consist of inspection and cleaning. Check the electrodes for
deterioration and the insulators for cracks. The electrode assembly is adjustable, if
defective replace with a new one. Be sure to replace the rubber boot over the spark
electrode and treat electrode leads with care. Because of high voltage any damage to the
insulation is a potential leak path. When a new electrode is put in, be sure to set the spark
gap and flame sensor dimension, as shown in Figure 7.

_____________________________________

X Blower Shelf Assembly

XI Combination Gas Valve

The blower assembly including the blower and motor, and motor mounting bracket can be
withdrawn as a unit after external wiring is disconnected.
?? Cleaning of the blower wheel is usually the only service required. Need for cleaning is
indicated if the air inlet of the burner housing show an accumulation of dust and lint, or if
the character of the flame—long, hazy and yellow (sooty)—indicates a deficiency of air.
Motor air cooling vents if present, should also be cleaned at this time.
?? If the motor must be replaced, remove the blower wheel first and remove the retainer
clips at the rubber motor grommets, pull the motor out of keyhole brackets. Remount in
reverse order, noting that brass flanges of rubber motor mounts are located against motor.
Do not omit the three clips. Position blower wheel on motor shaft to provide 1/8” inch
clearance between blower inlet opening and blower wheel ring.

_____________________________________

The 24 volt Combination Valve serves three functions:

1. Manual Gas Shut-off

2. Manifold gas pressure regulation

3.Automatic electric redundant (double seated) gas valve

?? For manual control the Manual Gas Cock Knob is turned full ON or full OFF.
?? The Combination Valve Gas Regulator has an outlet pressure setting range of 2.0" to

4.0" W.C. and is factory set for 2.0" W.C. Manifold Gas Pressure Tap is located on the
outlet end of the Combination Valve body.
?? If pressure adjustment is required for setting capacity, remove regulator cap for access
to slotted adjustment screw. Turning of adjustment screw counterclockwise reduces
pressure; clockwise increases pressure. Do not adjust past point where no change in
pressure is noted.

Note: Pressure setting can only be made with burner running and gas on.

CAUTION: If gas supply pressure is below its specified range during adjustment,
an overfire condition could result when pressure returns to normal, particularly if the
regulator adjustment screw is bottomed out. ALWAYS confirm that at least the
minimum rated gas pressure is being supplied to the burner during regulator
adjustments, and NEVER bottom out regulator screw.

8

9

Part 2

Part 2 Service

Service Continued

XI Combination Gas Valve

Continued

?? If the pressure regulator fails to maintain a constant manifold gas pressure within ±0.1"
W.C., and it is confirmed that the inlet gas pressure to the Combination Valve is a steady

14.0" W.C. maximum during standby, and a steady 5.0" W.C. minimum with the flame on,
the regulator portion of the valve is defective and the entire valve must be replaced.

CAUTION: If the Combination Valve has been moved or replaced, soap bubble
test for leaks with the burner running.

CAUTION: If leakage through the valve occurs on standby, as evidenced by the
presence of any flame, the entire valve should be replaced.

_____________________________________

XII Electronic Control

The electronic control is a 24 volt AC, solid state electronic device that automatically ignites
and monitors the main flame. It has an integral high voltage transformer and upon a call
for heat , applies high voltage to the spark electrode and 24 volts to the Combination Valve.
When the flame is proven, the spark is terminated and the burner run continues.
?? If the flame is not proven within 36 seconds or if the proof of flame is lost during the
burner run and is not re-established within 36 seconds, the control will shut off the
Combination Valve and LOCK OUT. To RESET the system, set operating control to OFF or
thermostat below room temperature for at least 30 seconds.
?? If the electronic control is changed, the replacement must be identical to the make and
model number, or it must be an authorized substitute.

WARNING: Explosion hazard. Can cause serious injury or death. This device can
malfunction if it gets wet. Never try to use a device that has been wet-replace it.

_____________________________________

Consumer Instructions

Maintenance

Keep the area around the burner clear and free of combustible materials, gasoline and other
flammable liquids or vapors. Do not obstruct burner air inlet or ventilation air.
?? The motor features permanently lubricated ball bearings and requires no routine oiling
maintenance.

IMPORTANT: Check the burner flame periodically. A proper NATURAL gas flame will appear
blue at the burner face with orange and yellow tips. A proper PROPANE gas flame will
appear blue at the burner face with yellow tips. If the flame is too rich, it will appear billowy
and yellow with hazy tips. If too lean, it will appear short and all blue. If the flame does not
appear proper, CONTACT A QUALIFIED SERVICE TECHNICIAN FOR CLEANING,

READJUSTMENT AND/OR REPAIR.

WARNING: If any flame is observed when the burner is on standby, or if the
ignition spark or valve operator is heard to come on before the motor reaches
operating speed, immediately turn off the Main Manual Shut-off Valve and burner
power. A dangerous condition has developed and must be corrected. CONTACT A
QUALIFIED SERVICE TECHNICIAN FOR CLEANING READJUSTMENT AND/OR
REPAIR.

WARNING: If PROPANE gas is used and the burner is located in a basement,
crawl space or confining space, contact your gas supplier about installing a GAS
LEAK warning device. PROPANE gas is heavier than air and can settle in low areas or
confined spaces. This would create a danger of explosion or fire. If you suspect a gas
leak, follow instructions on front cover of this manual.

_____________________________________

Lighting Instructions

1. SET OPERATING CONTROL TO OFF OR THERMOSTAT BELOW ROOM

TEMPERATURE FOR AT LEAST 30 SECONDS.

2. TURN MANUAL GAS COCK KNOB ON COMBINATION VALVE TO ON.

3. TURN BURNER POWER ON.

4. SET OPERATING CONTROL TO ON OR THERMOSTAT TO CALL FOR HEAT (THERE

IS A 30 SECOND PREPURGE).

5. WAIT 36 SECONDS. IF BURNER HAS FAILED TO LIGHT, OR IF BURNER LIGHTS

THEN GOES OUT AND SYSTEM GOES INTO SAFETY LOCKOUT, DE-ENERGIZE

THE SYSTEM BY SETTING OPERATING CONTROL TO OFF OR THERMOSTAT

BELOW ROOM TEMPERATURE FOR AT LEAST 30 SECONDS TO RESET THE

SYSTEM AND THEN SET OPERATING CONTROL TO ON OR THERMOSTAT TO

CALL FOR HEAT.

TO SHUT OFF

1. TURN MANUAL GAS COCK KNOB ON COMBINATION VALVE TO OFF.

2. TURN BURNER POWER OFF.

SHOULD OVERHEATING OF THE GAS UTILIZATION EQUIPMENT OCCUR:

1. Shut off the main manual shut-off gas valve to the equipment.

2. Do notshut off the power switch to the ECONOMITE burner, or the equipment pump or

blower.

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10

Trouble Chart

Trouble Chart

11

Make sure the thermostat and operating controls are calling for heat. Defective wiring or
loose connections can simulate the component defects outlined below. Check associated
wiring before replacing a component.

ELECTRICAL AND FLAME CHECKS MUST BE MADE IN ORDER LISTED.

I. Motor Will Not Run

or Motor Runs

in Repeated Cycles.

II. Motor Runs Continuously,

But No Flame.

A. Confirm 120V hot to neutral voltage and verify the circuit polarity and electrical ground,

between neutral and burner chassis metal.

B. Check 24V* operating control circuit between left T-T terminal and GND.

1. No voltage, transformer defective.

2. Very low voltage,* circuit overloaded or transformer defective.

C. Confirm 120V between hot wire and motor relay terminal 4:

1. No voltage, motor relay is defective.

2. Voltage present, motor is defective.
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A. Confirm that both Main Manual Shut-Off Valve and Manual Gas Cock Knob on

Combination Gas Valve are in the ON position.

B. Whenever the burner fails to light during the 6-second trial for ignition, or if the flame is

lost during the burner run and not re-established within 36 seconds (30 second
pre-purge) the Electronic Control will shut off the Combination Valve and LOCK OUT.
To RESET the Control for restart, set the operating control to OFF or thermostat below
room temperature for at least 30 seconds.

1. Check for 24V* between GND and Electronic Control 25V terminal. No voltage,

blower interlock circuit is defective.

2. If Electronic Control has a fuse, test for 24V from each end of fuse to strip terminal

GND.

C. For each of the following tests, reset the Electronic Control per step II.B. TESTS ARE

VALID ONLY DURING THE 6-SECOND TRIAL FOR IGNITION.

1. Turn Manual Gas Cock Knob to OFF. Check for 24V between the Electronic

Control 25V terminal and strip terminal GND. No voltage, defective Electronic
Control.

2.Check for 24V* between valve MV terminal and valve body:

a. With voltage, RESET Electronic Control and listen for audible CLICK as valve

operators open. No CLICK, replace valve.

3. Check for ignition spark (spark length approximately 5/32"). Since this is a capacitor

discharge system, observe closely when visually checking the spark as it is faint
and thread-like and may be overlooked in bright light.

a. Between Electronic Control high voltage terminal and GND. No spark,

defective Electronic Control.

b. Between Electronic Control high voltage terminal and Spark Electrode Wire .

No spark, broken wire, cracked insulator, or "spark gap" too wide, see Figure 7

c. Between spark electrode tip and distributor, see Figure 7. If spark is not visible

and/or cannot be heard, remove nozzle assembly (see Section IX Nozzle and
Electrodes) and ground it solidly to burner metal. No spark, replace ignition
electrode.

4.Turn Manual Gas Cock Knob to ON. Connect manometer to the manifold gas

pressure tap and during trial for ignition, check the gas pressure:

a. Pressure should be between 2.0" and 4.0" W.C. for NATURAL and PROPANE

and steady. Verify per Section VII Main Gas Spud that the spud orifice size
and manifold pressure are correct.

b. Zero, erratic low or high pressure: confirm that the inlet pressure to the

Combination Valve is between 5" and 14" W.C. for NATURAL and PROPANE
during standby and during trial for ignition.

c. If manifold pressure is zero, below 2.0" or above 4.0" W.C. for NATURAL and

PROPANE or erratic, the regulator section of the Combination Valve is
defective and the entire valve must be replaced.

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Trouble Chart

Trouble Chart Continued

III. Flame on Only During 6-

Second Trial for Ignition

A. With motor running check burner line voltage terminals for 120V as follows:

1. Between hot and neutral-120V; voltage OK.

2. Between hot and GND-120V: ground OK.

3. Between strip neutral and GND-"0"V: no backfeed, OK

B. Follow RESET procedure as specified in step II.B.

1. Check sense electrode position per Figure 7.

2. Check sense wire for continuity.

3. Connect DC microameter in series with Electronic Control SENSE terminal and
sensor wire. With flame on, flame signal should be at least 2 microamps.

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IV. Short Flame.**

V. Long Hazy Flame.**

VI. Gas Fails to Shut Off.

A. Low manifold gas pressure.
B. Main gas spud orifice too small.
C. Primary air adjustment open too far.

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A. High manifold gas pressure.
B. Main gas spud orifice too large.
C. Primary air adjustment closed too far.
D. Dirty blower wheel.

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A. Automatic electric (redundant) valve section of Combination Valve is defective and entire

valve must be replaced.

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* Normal low voltage:

Motor running-24V minimum.
Combination Valve energized-21V minimum.

** CAUTION: If changes are made in the Main Gas Spud Orifice size, Manifold Gas

Pressure or Primary Air Adjustment, change the installation Data Tag accordingly.

Midco International Inc.

4140 West Victoria Street * Chicago, Illinois 60646
tel [phone] * fax [phone] *
web www.midco-intl.com email [e-mail]

602

8471 09

Printed in USA