Installation and Operation Instructions |
Document 1065D |
Installation and Operation |
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Instructions for |
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Mighty Therm |
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Model HH |
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Sizes 2000-5000 |
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Hydronic Boilers |
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FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician, qualified in hot water heater installation and maintenance. Improper installation and/or operation could create carbon monoxide gas in flue gases which could cause serious injury, property damage, or death. Improper installation and/or operation will void the warranty.
WARNING
If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or loss of life.
Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other 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 nearby phone. Follow the gas supplier's instructions.
•If you cannot reach your gas supplier, call the fire department.
Installation and service must be performed by a qualified installer, service agency, or gas supplier.
H0147600D
A subsidiary of BRADFORD WHITE Corporation
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TABLE OF CONTENTS
SECTION 1. |
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General Information |
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1A. |
Introduction................................................... |
3 |
1B. |
Flow Requirements ...................................... |
4 |
1C. |
Variable Water Flow Systems ...................... |
4 |
1C-1. A Special Note About 3-Way |
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Water Valves ................................................ |
5 |
1C-2. |
System Pressure Requirements ................... |
5 |
1D. |
Warning Regarding Chilled |
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Water Systems ............................................. |
5 |
SECTION 2. |
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Installation |
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2A. |
Boiler Placement .......................................... |
5 |
2B. |
Installation of Indoor Boilers ......................... |
6 |
2B-1. |
Combustion Air Supply ................................. |
6 |
2B-2. |
Venting ......................................................... |
7 |
2C. |
Installation of Outdoor Heater....................... |
7 |
2D. |
Freeze Protection ......................................... |
8 |
2E. |
Gas Supply and Piping ................................. |
8 |
2F. |
Electrical Wiring ............................................ |
9 |
2G. |
Piping of System to Boiler ............................ |
9 |
2H. |
Filling Fully-Connected System .................. |
10 |
SECTION 3. |
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Operation |
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3A. |
Initial Start Up ............................................. |
10 |
3B. |
To Start Up System .................................... |
11 |
3C. To Turn Off Boiler ....................................... |
12 |
3D. To Shut Down System ................................ |
12 |
SECTION 4. |
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Maintenance |
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12 |
SECTION 5. |
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Troubleshooting and Analysis of |
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Service Problems |
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13 |
SECTION 6. |
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Conversion of VW from Indoor |
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to Outdoor Models |
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15 |
SECTION 7. |
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Parts Description and Order Numbers |
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MightyThermHydronicBoiler |
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SECTION 1.
General Information
IMPORTANT WARNING:
The Model HH hydronic boiler must be installed in accordance with the procedures outlined in this manual. Warranty does not apply to boilers not installed or operated in accordance with these procedures. Consult local building and safety codes before proceeding with work. The installation must conform to the requirements of the authority having jurisdiction or, in the absence of such requirements, to the latest edition of the National Fuel Gas Code, ANSI Z223.1 and/or in Canada, CAN1-B149 requirement.
When required by the authority having jurisdiction, the installation must conform to American Society of Mechanical Engineers safety code for controls and safety devices for automatically fired boilers No. CSD-1, and in Canada, CGA3.3. Any modification to the boiler, its gas controls, gas orifices, wiring or draft diverter may void the Laars warranty. If field conditions require such modifications, consult Factory.
1A. Introduction
This manual provides information for the installation and operation of Laars boilers. It is strongly recommended that all application and installation procedures be reviewed completely before proceeding with the installation. Consult the factory, or local factory representative, with any problems or questions regarding this equipment. Experience has shown that most operating problems are caused by improper installation.
Model HH boilers are offered in two configurations: An indoor version and an outdoor version. The indoor version is convertible for outdoor use with the installation of a conversion kit as described in Section 6 of this manual. The two configurations are shown in Figure 1.
Some accessory items are shipped in separate packages. Verify receipt of all packages listed on the packing slip. Inspect everything for damage immediately upon delivery, and advise the carrier of any shortages or damage. Any such claims should be filed with the carrier. The carrier, not the shipper, is responsible for shortages and damage to the shipment whether visible or concealed.
Indoor |
Outdoor |
When boiler is ordered with stage or modulated control and sales order states it is to be used on a variable flow system, the temperature controller is factory installed in the outlet water.
Figure 1. Boiler Configuration.
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1B. Flow Requirements
All low volume hydronic boilers must have continuous flow through the heat exchanger when firing, for proper operation. The system pump must be capable of developing sufficient pressure to overcome the resistance of the boiler plus the entire circulating system at the designated GPM (see Table 1). The temperature rise across the boiler should never exceed 40° F.
NOTE: Water entering boiler should be 105°F minimum.
1C. Variable Water Flow Systems
Heating systems using zone valves, zone pumps or 3-way valves can experience reduced water flow through the boiler. This can result in an excessive water temperature rise and unstable boiler operation. If system water flow is variable, it must not be allowed to fall below 30% of full flow. The boiler must be equipped with staged or modulated fire with the temperature sensor installed in the outlet water. State variable flow when ordering. Laars recommends primary-secondary pumping for all variable flow systems. Primary-secondary pumping is mandatory for variable flow systems where minimum flows are less than 30% of full flow conditions. The boiler pump in a primary-secondary system maintains constant flow through the boiler even though the system flow is variable. In a primary-secondary system the pressure drop of the boiler is not added to the system (see Figure 2).
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Convectors Baseboards |
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or Fan Coils |
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Zone Valves |
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Compression Tank |
Pump |
12" |
System Pump |
Max. |
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(Location varies |
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with model) |
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Unit |
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Figure 2. Primary-Secondary System.
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20°F |
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25°F |
30°F |
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35°F |
Size (I) |
Size (E) |
GPM |
H/L |
GPM |
H/L |
GPM |
H/L |
GPM |
H/L |
20001P |
------ |
164 |
3.91 |
131 |
3.6 |
109 |
1.8 |
94 |
0.7 |
2P |
------ |
164 |
10.5 |
131 |
7.4 |
109 |
4.9 |
94 |
3.0 |
24501P |
22001P |
201 |
5.9 |
161 |
3.9 |
134 |
3.8 |
115 |
2.3 |
2P |
2P |
201 |
16.4 |
161 |
10.2 |
134 |
7.7 |
115 |
5.7 |
30501P |
28001P |
250 |
9.3 |
200 |
5.9 |
167 |
4.5 |
143 |
3.8 |
2P |
2P |
* |
* |
200 |
16.4 |
167 |
12.5 |
143 |
8.5 |
35001P |
32001P |
284 |
12.0 |
230 |
8.7 |
189 |
5.7 |
164 |
3.9 |
2P |
1P |
* |
* |
* |
* |
189 |
16.8 |
164 |
10.5 |
40501P |
36001P |
332 |
17.2 |
266 |
11.9 |
222 |
8.1 |
190 |
5.8 |
2P |
2P |
* |
* |
* |
* |
222 |
24.0 |
190 |
16.0 |
45001P |
40001P |
369 |
21.75 |
295 |
13.2 |
246 |
10.0 |
211 |
7.0 |
2P |
2P |
* |
* |
* |
* |
* |
* |
211 |
20.0 |
50001P |
45001P |
410 |
27.0 |
328 |
16.8 |
273 |
13.0 |
234 |
9.0 |
2P |
2P |
* |
* |
* |
* |
* |
* |
* |
* |
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HIGH |
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NORMAL |
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LOW |
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* Not recommended, consult factory.
I=Indoor, E=Outdoor. GPM=Water flow. H/H=Pressure drop (head loss)through the boiler, expressed in Ft. of H20. 1P=Single-pass heat exchanger. 2P=Two-pass heat exchanger. Shaded area is the recommended flow and temperature rise.
Table 1. Water Flow, Temperature Rise and Pressure Drop.
MightyThermHydronicBoiler |
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1C-1. A Special Note About 3-Way Water Valves
3-way water valves (2 position or proportional) are sometimes used to divert water around a boiler and control the temperature of water being supplied to the system. Valves installed in this manner must be supplied with an end switch or some other suitable control to shut off the boiler when the flow is reduced to 30%. The boiler must be supplied with staged or modulated fire as indicated in Section 1C, Variable Water Flow Systems.
It is often possible to accomplish excellent water temperature control without 3-way valves through proper application of staged or modulated firing systems. Consult the factory or local Laars representative for assistance with such systems.
1C-2. System Pressure Requirements
The Model HH boilers are designed to operate on closed, pressurized systems. A minimum of 12 psi should be maintained on the system where boiler supply water temperatures are 200°F or less. If higher temperatures are required, the minimum system pressure should be at least 15 psi above the water vapor pressure corresponding to the elevated water temperature.
The Model HH boilers are not suitable for open systems unless the supply water temperatures are kept below 180°F, and a minimum of 5 psi static head is maintained at the boiler.
Suggested Wiring Diagram For
Tempering System Water at
Changeover from Heating to Cooling
DPDT Manual or Automatic |
Clock Timer |
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Change-over Switch |
Auto-resetting |
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DPDT - Set at Change-over |
Set at 15 minute SPDT |
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Temperature |
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115/24V |
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Transformer |
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To Boiler |
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Valve Motors |
and |
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Chiller |
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2-Pos |
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Chiller |
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3-Wire - 24V |
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From |
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By-pass |
From |
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Boiler |
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System |
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To |
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System |
3-Way Valve No. 1 |
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3-Way Valve No. 2 |
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Change-over |
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To By-pass |
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(Heating and Cooling) |
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Both Heater and |
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Chiller |
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1D. Warning Regarding Chilled
Water Systems
When a boiler is connected to an air conditioning system where the same water is used for heating and cooling, chilled water must be prevented from entering the boiler. When changing such a system from cooling to heating, the chilled water should be allowed to circulate through the building after the chiller has been turned off long enough for the water to warm up to at least 70°F before the water is allowed to flow into the boiler. It is equally important to prevent hot water from entering the chiller. The system shown in Figure 3 is suggested to make sure that the system water is neither too hot nor too cold when a changeover from heating to cooling, or vice versa, takes place. When a boiler is connected to heating coils located in air handling units (where they may be exposed to refrigerated air circulation), the boiler piping system shall be equipped with a flow control valve or other automatic means to prevent gravity circulation of chilled water through the boiler. Chilled water in the boiler will create condensate on the boiler tubes which will drip on the burners and may extinguish the pilot.
Boilers installed in violation of either of the above requirements may void the warranty.
SECTION 2.
Installation
2A. Boiler Placement
The boiler must be placed to provide clearances on all sides for maintenance and inspection. There must also be minimum distances maintained from combustible surfaces.
All boilers must be installed on a noncombustible floor. Under no circumstances can boilers be installed on carpeting.
The National Fuel Code allows a boiler to be placed on a combustible surface when such an installation complies with the local codes. This code specifies the surface under the boiler be protected with hollow masonry no less than 4" thick, covered with sheet metal at least 20 Ga. in thickness. Such masonry
Clearance |
Indoor |
Outdoor |
From |
(Inches) |
(Inches) |
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Top |
24 |
— |
Water Connection Side |
24 |
24 |
Opposite Side |
24 |
24 |
Front |
48 |
48 |
Rear |
24 |
24 |
Vent |
6 |
— |
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Figure 3. Boiler-Chiller Installation. |
Table 2. Minimum Clearances from Combusible Surfaces. |
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must be laid with ends unsealed, and joints matched in such a way as to provide a free circulation of air from side to side through the masonry (see Figure 4).
2B. Installation of Indoor Boilers
2B-1. Combustion Air Supply
1.The boiler location must provide sufficient air supply for proper combustion, and ventilation of the surrounding area as outlined in the latest edition of ANSI standard Z223.1, and/or in Canada CAN1-B149 requirement, and any local codes that may be applicable. Inadequate combustion air supply may result in incomplete combustion and consequent sooting of the heat exchanger and unsafe operation of the boiler.
2.In general, in the U.S., these requirements specify that boiler rooms, which represent confined spaces, should be provided with two permanent air supply openings communicating directly through the wall to outside air; one within 12 inches of the ceiling, the other within 12 inches of the floor. Each opening should have a minimum free area of one square inch per 4,000 BTUs/H input rating of all appliances in the enclosed area. See Table 3 for recommended air supply for each model. An improperly ventilated equipment room can get excessively hot and cause accelerated deterioration of controls and electrical components.
Base Must Extend Out |
Metal Plate 20 |
Min. 12" On All Sides |
Ga. Min. |
Of Heater Frame |
Under Entire |
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Heater |
Concrete Blocks Or Tile
Min. 7" High With 3" Min.
Air Openings
Blocks must provide solid base and be braced so they cannot slip out of place. Air openings in blocks must be arranged to provide unobstructed opening through entire width or length of base.
NOTE: In Canada (Table 3 does not apply) consult local building and safety codes or, in the absence of such requirements, follow CGA requirement, and/or CAN1-B149 standard.
3.Exhaust Fans or Vents: Any equipment which exhausts air from the boiler room can deplete the combustion air supply or reverse the natural draft action of the venting system. This could cause flue products to accumulate in the boiler room. Additional air must be supplied to compensate for such exhaust. The information in Table 3 is not applicable in installations where exhaust fans or blowers of any type are used. Such installations must be designed by qualified engineers.
4.If a blower or fan is used to supply air to the boiler room, the installer should make sure it does not create drafts which could cause nuisance shutdowns of the pilot. If a blower is necessary to provide adequate combustion air to the boiler, a suitable switch or equivalent must be wired into the boiler control circuit to prevent the boiler from firing unless the blower is operating.
5.The boiler must be completely isolated and protected from any source of corrosive chemical fumes such as emitted by trichlorethylene, perchlorethylene, chlorine, etc.
Indoor |
Each Opening* |
Size |
(Square Inches) |
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2000 |
500 |
2450 |
613 |
3050 |
763 |
3500 |
875 |
4050 |
1013 |
4500 |
1125 |
5000 |
1250 |
Net Free Area in Square Inches*
*Area indicated is for one of two openings; one at floor level and one at the ceiling, so the total net free area would be double the figures indicated. For all other conditions, refer to latest edition of ANSI Bulletin Z223.1.
NOTE: Check with louver manufacturers for Net Free Area of louvers. Correct for screen resistance to the Net Free Area if a screen is installed. Check all local codes applicable to combustion air.
Figure 4. Non-combustible Base. |
Table 3. Minimum Recomended |
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Air Supply To Boiler Room. |
MightyThermHydronicBoiler |
Page 7 |
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2B-2. Venting
1.Laars boilers have built-in draft diverters for natural draft operation and must not be connected into any portion of a mechanical draft system under positive pressure. The flue outlet must be connected to a clear, unobstructed vent of adequate capacity terminating above the highest point of the building with an approved vent cap. The venting system should be installed according to the latest edition of ANSI Z223.1 and any local codes having jurisdiction and/or in Canada follow CAN1-B149 standard.
IMPORTANT NOTE: Do not use sheet metal screws at the snap lock joints of Type B gas vents.
2.Do not weld or fasten the vent pipe to the boiler draft hood. The weight of the stack must not rest on the boiler. The draft hood and boiler top must be easily removable for normal boiler service and inspection.
3.Avoid long horizontal runs of the vent pipe, and too many 90° elbows, reductions and restrictions. Horizontal runs should have at least a ¼" rise per foot in the direction of flow. A vent connector shall be supported for the design and weight of the material employed to maintain clearances and prevent physical damage and separation of joints.
4.Avoid terminating boiler vents near air conditioning or air supply fans. The fans can pick up exhaust flue products from the boiler and return them inside the building, creating a possible health hazard. A minimum of 4 feet horizontal distance must be maintained from electric meters, gas meters, and relief equipment.
Figure 7. Method of Installing a Tee Sediment Trap.
5.Always use double-wall or insulated vent pipe (Type B or equivalent). In cold weather, uninsulated outside vents can chill the rising flue products, blocking the natural draft action of the venting system. This can create a health hazard by spilling flue products into the boiler room.
6.Avoid oversize vent piping or extremely long runs of the pipe which may cause excessive cooling and condensation. Rule of Thumb: The total length of the vent, including the connector and any offset, should not exceed 15 feet for every inch of vent diameter. Longer total lengths shown in venting tables are based on maximum capacity, not condensation factors.
7.When the installation of a draft fan is necessary in the venting system to which a Laars boiler is to be connected, the installation should be engineered by competent personnel following good engineering practices. The draft fan supplier should be consulted for correct size. The installation should be in accordance with the latest edition of ANSI Z223.1 and any local codes having jurisdiction, in Canada follow CAN1-B149 standard. When a draft fan is installed, a suitable draft switch must be used and wired into the boiler control circuit at terminal designated “Field Interlock,” to prevent firing of the boiler unless a positive draft has been established (see Figure 5).
2C. Installation of Outdoor Boilers
Caution
Outdoor installations are not recommended in areas where the danger of snow blockage exists.
1.Locate the boiler to provide the minimum clearances as listed in Section 2A, “Placement of Boiler.”
2.Do not locate the boiler in an enclosure or wall recess. Avoid location where wind deflection off structures might cause down draft. When such
Window |
Or Grill |
Indoor |
WRONG |
Room |
Figure 6. Incorrect Outdoor Installation of Boiler.
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wind conditions are possible, locate the boiler at least three (3) feet from the structures.
3.Never install the boiler under any kind of roof overhang. Do not locate the boiler below or adjacent to any doors, windows, louvers, grills, etc. which communicate in any way with an inhabited area of a building. Even though such communication might be through another structure such as a garage or utility room (see Figure 6).
2D. Freeze Protection
Boiler installations are not recommended in areas where the danger of freezing exists unless proper precautions are made for freeze protection. Maintaining a mixture of 50% water and 50% ethylene glycol is the preferred method of freeze protection for hydronic systems. This mixture will protect the boiler to temperatures of about -35°F. To get the desired temperature rise across the boiler when this mixture is used, increase the G.P.M. flow recommended for water by 15%. Increase the head loss requirement by 20%.
2E. Gas Supply and Piping
Review the following instructions before proceeding with the installation.
1.Verify that the boiler is fitted for the proper type of gas by checking the rating plate. Laars boilers are normally equipped to operate below a 2000 foot altitude. Boilers equipped to operate at higher altitudes have appropriate stickers or tags attached.
2.Use the figures in Table 4 to provide adequate gas piping (check local code for BTU capacity required).
3.A trap (drip leg) must be provided ahead of the gas controls (see Figure 7). Where required by code, provide a second manual gas shutoff valve. Do not remove manual valve furnished with the boiler.
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Gas Supply |
To |
Inlet |
Equipment |
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Inlet |
Tee |
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Fitting |
Nipple |
3" Min. |
Cap |
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4.The boiler and its individual shutoff valve must be disconnected from the gas supply piping system during any pressure testing of that system at test pressures in excess of ½ psig. The boiler must be isolated from the gas supply piping system by closing its individual manual gas shutoff valve during any pressure testing of the gas supply piping system at test pressures equal to or less than ½ psig.
5.Provide gas supply pressure to the boiler as follows:
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Natural Gas |
LPG |
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Min. (inches water column) |
7 |
11 |
Max.(inches water column) |
9 |
14 |
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Note: The boiler and all other gas appliances sharing the boiler gas supply line must be firing at maximum capacity to properly measure the inlet supply pressure. Low gas pressure could be an indication of an undersize gas meter and/or obstructed gas supply line.
6.The correct burner manifold gas pressure is stamped on the rating plate. The regulator is preset at the factory, and normally requires no further adjustment.
7.The gas manifold and control assembly was tested and conform to the safe lighting and other performance criteria specified in the latest editions of ANSI Z21.13 and CGA 3.3 Low Pressure Boiler Standard.
Distance from Gas Meter or Last Stage Regulator
Indoor |
Outdoor |
0-100' |
100-200' |
200-300' |
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Size |
Size |
Nat. |
Pro. |
Nat. |
Pro. |
Nat. |
Pro. |
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2000 |
------ |
2½ |
2 |
3 |
2½ |
3 |
3 |
2450 |
2200 |
3 |
2½ |
3 |
2½ |
3½ |
3 |
3050 |
2800 |
3 |
2½ |
3½ |
3 |
3½ |
3 |
3500 |
3200 |
3 |
2½ |
3½ |
3 |
4 |
3½ |
4050 |
3600 |
3½ |
3 |
4 |
3½ |
4 |
3½ |
4500 |
4000 |
3½ |
3 |
4 |
3½ |
5 |
4 |
5000 |
4500 |
4 |
3½ |
4 |
3½ |
5 |
4 |
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NOTES:
These figures are based on 1/2" water column pressure drop.
Check supply pressure and local code requirements before proceeding with work.
Pipe fittings must be considered when determining gas pipe sizing.
Figure 7. Method of Installing a Tee Sediment Trap.
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