Midco DS24A User Manual

The ECONOMITE Models DS24A direct spark ignition conversion burner is adaptable to any type gas utilization equipment, includ-
ing gravity and forced circulation furnaces and boilers, and is particularly recommended for horizontal and downdraft 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.

INSTALLER: Inform and demonstrate to the user

the correct operation and maintenance of this gas
utilization equipment. Inform the userof 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.

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

Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.

Installation and service must be per­formed by a qualified installer, serv­ice agency or the gas supplier.

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
phone. Follow the gas suppliers'
instructions.

• If you cannot reach your gas
supplier, call the fire department.

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

as described in this manual is required, contact a qualified service agency. DO NOT
ATTEMPT REPAIRS. An inadvertent service error could result in a dangerous condition.

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

ANSI Z21.17
CONVERSION
BURNERS

Installation and Service Instructions

Midco International

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

Midco

INTERNATIONAL

799

8470-71

Printed in U.S.A.

Economite DS24A

Conversion Burners

Part 1 Installation

Specifications

I Ventilation

II Preparation of the Gas

Utilization Equipment

III Combustion Chamber

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

225 MBH

150 MBH
Gas Pressure Required

NATURAL or PROPANE
Standard Voltage
Flame Safety
Main Automatic Valve

47 SCFM*

225 MBH***

50 MBH***

4 inches
8 inches

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

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

5.0" to 14.0" W.C.

120 Volts 60 Cycle

Direct Spark Ignition of Main Flame, Electronic Safety

3 Function Redundant

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 of additional elevation.

CAUTION: The ECONOMITE DS24A 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 grilles, 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 grilles sized at not less than one square inch free area per 4,000 BTU of burner
input. When ventilating through horizontal ducts, grilles 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.

■■

■■ 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.

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.

2

III Combustion Chamber

Continued

IV Chimney, Vent

Connector*,

and Draft Control

*Formerly referred to as Flue Pipe

3

■■

■■ 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 liner or target wall may be necessary if the combus-

tion 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 bur ner tube, or the stainless steel sleeve

that is included with the burner, must be sealed
air tight into the combustion chamber liner open­ing with refractory material as shown by Figures
1 and 2. The sleeve is preferred as it is designed
to properly locate the end of the tube relative to
the inside wall of the combustion chamber, and
to permit burner removal without breaking the
seal.

CAUTION: In no case should the burner
tube be allowed to extend into the chamber
proper; it must be set at least 1" short of the
inside surface.

■■

■■ Special heat resistant alloy extension tubes and instructions are available for those applications

where the burner tube is too short to reach the combustion chamber (such as old-fashioned grav­ity warm air furnace installations).

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.

■■

■■ Before permanently setting the burner in

place, check that the nozzle ribbon is free of for­eign materials and also that the electrodes have
not been damaged or displaced, see Figure 7.

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 Z21.8 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 connector, 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.

Figure 1: Dry Base Boiler with Combustion

Chamber Liner (Warm Air Furnace

Construction is Similar)

Figure 2: Wet Base Boiler with

Combustion Chamber Unlined

Maximum

Input

V ent Connector

Dia.

100 MBH
143 MBH
195 MBH
225 MBH

5"
6"
7"
8"

Table 1: Recommended Vent

Connector Sizes

Source: ANSI Z21.8b 1993, Installation

of Domestic Gas Conversion Burners.

For other applications,

consult appropriate standards.