Weil-McLain GV90+3, GV90+4, GV90+5, GV90+6 User Manual

Gas-Fired W ater Boilers

Boiler Manual

• Installation

• Startup

• Maintenance

• Parts

This manual must only be used by a qualiﬁed h eating installer/service technician. BEFORE ins talling, read

all instructions in this manual and all other information shipped with the boiler. Perf orm steps in the order given. Failure to comply could result in severe personal injury, death or substantial property damage.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

How it works . . .

1 Integrated boiler control

The integrated boiler control (IBC) responds to signals from the room thermostat, air pressure switch, inlet water sensor and boiler limit circuit to operate the circulators, gas valve, igniter and blower. When a room thermostat calls for heat, the IBC starts the system circulator and blower.

The IBC runs the blower to purge the boiler ﬂue passages, then turns on the igniter and lets it warm up.

After igniter warm-up, the IBC opens the gas valve, turns the igniter off, and checks for ﬂame. The ﬂame must come on within 4 seconds or the IBC will shut down and try the full cycle again.

When the room thermostat is satisﬁed, the IBC turns off the boiler components and waits for the next heat call.

The IBC indicator lights show normal sequence when the lights are on steady. When a problem occurs, the IBC ﬂashes combinations of lights which indicate the most likely reason for the problem.

LEGEND

a Supply to system, 1” NPT

b Return from system, 1” NPT

c Combustion air inlet ﬁtting —

3” PVC connection

d Flue outlet — 3” PVC connec-

tion

2 Transformer

The control transformer reduces line voltage to 24 volts for the gas valve and limit circuit.

3 Blower

The blower pulls in air and mixes it with gas from the gas valve. The blower forces this mixture into the burner for combustion inside the boiler chamber.

4 Recuperator

The recuperator is a stainless steel heat exchanger that increases boiler efﬁciency by extracting additional heat from the ﬂue gases. Return water passes through the recuperator before entering the boiler.

5 Water temperature limit switch

The water temperature limit switch turns off the gas valve if the temperature in the boiler goes above its setting. (The circulators will continue to run as long as there is a call for heat.)

6 System circulator

The system circulator circulates water through the external (system) piping. The ﬂow rate of the circulator is controlled by the IBC, depending on the temperature of the water entering the boiler sections. Pump must remain on boiler — do not remove.

7 Bypass circulator

The IBC operates the bypass circulator to mix hot water from the boiler outlet with colder return water from the system as needed to prevent condensation of ﬂue gases in the cast iron heat exchanger.

When the water returning to the boiler is below 140°F, the IBC regulates the bypass circulator and system circulator ﬂow rates to raise the return water temperature up to 140°F before it enters the cast iron sections. By balancing these ﬂow rates, the IBC can protect against condensation in the cast iron heat exchanger even if return water is as low as 60°F.

Pump must remain on boiler — do not remove.

e Gas valve — negative pressure

regulated gas control

f Pressure/temperature gauge

g Flueway inspection port cover

h Sensor hose trap

i Manual air vent

j Relief valve

k Thermal fuse — a one-time fuse

device that shuts boiler off if ﬂue temperature exceeds its setpoint

m Condensate trap line — shipped

loose with boiler, ﬁeld installed

n Condensate drain connection —

½” PVC female

8 Air pressure switch

The air pressure switch signals the IBC, telling the control whether air is moving through the blower.

9 Water temperature sensor

The water temperature sensor monitors the temperature of the water entering the boiler sections. The sensor sends this information to the IBC. The IBC determines how much to adjust the circulator ﬂow rates to provide at least 140°F water to the cast iron heat exchanger.

This boiler uses a negative-pressureregulated gas valve, set for an outlet pressure approximately –0.20” water column.

DO NOT set the outlet pressure higher

than factory setting.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

GV90+ Water Boiler

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Contents

How it works . . . . . . . . . . . . . . 2

GV90+ Water Boiler . . . . . . . . .3

Please read before proceeding . . .5

Prepare boiler location . . . . . . .6

Installations must follow these codes: . . . 6

High altitude installations. . . . . . . . . . 6

Residential garage installation . . . . . . . 7

Check oriﬁce plate — replace if necessary . 8

Install condensate trap. . . . . . . . . . . . 9

Install high altitude air pressure switch when

required (only above 5,550 feet) . . . . . . 9

Rotate the boiler into position . . . . . . 10

Perform hydrostatic pressure test. . . . . 11

Install water piping . . . . . . . . 12

General piping information. . . . . . . . 12

Install relief valve . . . . . . . . . . . . . 12

Expansion tank. . . . . . . . . . . . . . . 13

System water piping methods. . . . . . . 15

Circulators . . . . . . . . . . . . . . . . . 15

Simpliﬁed pipe/circulator selection . . . 15 Baseboard system piping — CIRCULATOR

zoning (primary/secondary) . . . . . . . 16

Baseboard system piping — ZONE VALVE

zoning (direct connection) . . . . . . . . 16

Radiator system piping . . . . . . . . . . 18

Single-zone radiant heating or heat pump 19

Adjust balancing valves . . . . . . . . . . 19

Multi-zone radiant heating system . . . . 20

Piping snow melt systems or combination

snow melt/space heating systems . . . . . 21

Water chiller systems . . . . . . . . . . . 22

Multiple boiler installations . . . . 23

Placing multiple boilers . . . . . . . . . . 23

Controlling multiple GV90+ boilers . . . 23

Piping multiple GV90+ boilers . . . . . . 23

Multiple boiler water piping. . . . 24

Easy-Fit® piping installation . . . . . . . 24

Venting & air — general. . . . . . 29

When removing a boiler from an existing

common vent system . . . . . . . . . . . 29

Existing vent test procedure. . . . . . . . 29

Provide combustion air:. . . . . . . . . . 30

Vent and air termination options . . . . . 30

DIRECT VENT installations . . . . . . . 30

DIRECT EXHAUST installations. . . . . 30

Combustion air contamination: . . . . . 30

Manifolded combustion air option for DIRECT VENT multiple boiler installations 31

Air manifold sizing . . . . . . . . . . . . 31

Commonwealth of Massachusetts

installations . . . . . . . . . . . . 34

Vent termination requirements . . 35

DIRECT VENT — Boiler room air

openings . . . . . . . . . . . . . . 36

DIRECT VENT — Sidewall with W-M

vent/air plate . . . . . . . . . . . . 37

DIRECT VENT — Sidewall with sepa-

rate pipes. . . . . . . . . . . . . . 39

DIRECT VENT — Sidewall with 3”

concentric . . . . . . . . . . . . . 41

DIRECT VENT — Vertical with sepa-

rate pipes. . . . . . . . . . . . . . 43

DIRECT VENT — Vertical with 3”

concentric . . . . . . . . . . . . . 45

Concentric termination assembly

(sidewall or vertical). . . . . . . . 47

Vent and air piping and boiler con-

nections . . . . . . . . . . . . . . 48

DIRECT EXHAUST & DIRECT VENT . 48

Follow termination instructions . . . . . 48

Installing vent and air piping . . . . . . . 48

DIRECT EXHAUST ONLY . . . . . . . . 48

DIRECT EXHAUST — Boiler room air

openings . . . . . . . . . . . . . . 49

Combustion air provision. . . . . . . . . 49

Sizing combustion air openings . . . . . 49

Special considerations . . . . . . . . . . . 49

GV90+ boiler WITHOUT other appliances

in room . . . . . . . . . . . . . . . . . . . 50

Air openings . . . . . . . . . . . . . . . . 50

GV90+ boiler WITH other appliances in

room . . . . . . . . . . . . . . . . . . . . 50

DIRECT EXHAUST — Sidewall . . 51 DIRECT EXHAUST — Vertical . . . 53

Gas piping . . . . . . . . . . . . . 54

Connecting gas supply piping. . . . . . . 54

Natural Gas. . . . . . . . . . . . . . . . . 55

Propane Gas . . . . . . . . . . . . . . . . 55

Wiring . . . . . . . . . . . . . . . 56

Field wiring. . . . . . . . . . . . . . . . . 56

Start-up. . . . . . . . . . . . . . . 59

Freeze protection (when used) . . . . . . 59

Clean system to remove sediment . . . . 59

Water chemistry . . . . . . . . . . . . . . 59

Antifreeze. . . . . . . . . . . . . . . . . . 59

Check for gas leaks. . . . . . . . . . . . . 60

Fill and test water system . . . . . . . . . 60

Verify gas/air oriﬁce plate . . . . . . . . . 61

Check thermostat circuit(s) . . . . . . . . 61

Inspect/ﬁll condensate system . . . . . . 61

Final checks before starting boiler . . . . 62

To start the boiler . . . . . . . . . . . . . 62

If boiler does not start correctly . . . . . 62

Check system and boiler after start-up. . 62 Gas valve adjustment — altitude over 5,500

feet ONLY . . . . . . . . . . . . . . . . . 62

Final checklist . . . . . . . . . . . . . . . 64

Annual start-up and general mainte-

nance schedule . . . . . . . . . . 67

Annual start-up . . . . . . . . . . 68

Address reported problems . . . . . . . . 68

Inspect boiler area . . . . . . . . . . . . . 68

Inspect boiler interior . . . . . . . . . . . 68

Inspect condensate drain system . . . . . 68

Inspect all piping for leaks . . . . . . . . 68

Inspect gas piping . . . . . . . . . . . . . 68

Inspect the water system. . . . . . . . . . 68

Inspect expansion tank . . . . . . . . . . 68

Inspect air openings . . . . . . . . . . . . 69

Inspect vent system and air piping . . . . 69

Inspect boiler heating surfaces . . . . . . 69

Inspect recuperator . . . . . . . . . . . . 69

Inspect igniter . . . . . . . . . . . . . . . 69

Inspect temperature mixing system . . . 70

Inspect limit controls and cutoffs. . . . . 70

Inspect gauges . . . . . . . . . . . . . . . 70

Inspect blower motor . . . . . . . . . . . 70

Inspect oiled-bearing circulators . . . . . 70

Inspect boiler relief valve . . . . . . . . . 71

To complete Annual Start-up, perform

startup and checks: . . . . . . . . . . . . 71

Review with owner. . . . . . . . . . . . . 71

Service & maintenance . . . . . . 72

Cleaning boiler heating surfaces . . . . . 72

Inspecting and cleaning the recuperator . 73

Troubleshooting . . . . . . . . . . 75

VERIFY PROPER OPERATION AFTER

SERVICING. . . . . . . . . . . . . . . . . 75

Before troubleshooting . . . . . . . . . . 75

Check the following . . . . . . . . . . . . 75

Checking the air pressure switch . . . . . 75

Igniter. . . . . . . . . . . . . . . . . . . . 76

Gas Valve . . . . . . . . . . . . . . . . . . 76

Blower Housing . . . . . . . . . . . . . . 76

Thermal fuse . . . . . . . . . . . . . . . . 76

Return temperature sensor . . . . . . . . 76

IBC (integrated boiler control) IBC indicator lights — lockout modes . . 77 IBC indicator lights — non-lockout modes

. . . . . . 77

Replacement parts . . . . . . . . 89

Dimensions and ratings. . . . . 100

NOTES . . . . . . . . . . . . . . 104

NOTES . . . . . . . . . . . . . . 106

Handling ceramic ber and ber-

glass materials. . . . . . . . . . 107

Installation and service

certicate . . . . . . . . . . . . 108

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Please read before proceeding

Hazard denitions

The following deﬁned terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or to important information concerning the life of the product.

Indicates presence of hazards that will cause severe

personal injury, death or substantial property damage.

Indicates presence of hazards that can cause severe

personal injury, death or substantial property damage.

Indicates presence of hazards that will or can cause

minor personal injury or property damage.

Indicates special instructions on installation, op-

eration or maintenance that are important but not related to personal injury or property damage.

Installer— Read all instructions, including this

manual and all other information shipped with the boiler, before installing. Perform steps in the order given.

User — This manual is for use only by a qualiﬁed

heating installer/service technician. Refer to User’s Information Manual for your reference.

User — Have this boiler serviced/inspected by a

qualiﬁed service technician, at least annually.

Failure to comply with the above could result in

severe personal injury, death or substantial property damage.

Write in the CP number in the space provided on

the Installation certiﬁcate on page 108 if not already shown.

When calling or writing about the boiler— Please

have the boiler model number from the boiler rating label and the CP number from the boiler jacket.

Consider piping and installation when determining

boiler location.

Any claims for damage or shortage in shipment

must be ﬁled immediately against the transportation company by the consignee.

Commonwealth of Massachusetts

When the boiler is installed within the Commonwealth of Massachusetts, comply with the following.

• This product must be installed by a licensed plumber or gas ﬁtter.

• If antifreeze is used, a reduced pressure back-ﬂow preventer device shall be used.

• If sidewall vent or vent/air is installed, see instructions on page 34.

Failure to adhere to the guidelines on this

page can result in severe personal injury, death or substantial property damage.

When servicing boiler —

• To avoid electric shock, disconnect electrical supply before performing maintenance.

• To avoid severe burns, allow boiler to cool before performing maintenance.

• This boiler contains ceramic fiber and fiberglass materials. Refer to the WARNING and instructions on page 107.

Boiler operation —

• Do not block ﬂow of combustion or ventilation air to boiler.

Should overheating occur or gas supply fail to

•

shut off, DO NOT turn off or disconnect electrical

supply to circulator. Instead, shut off the gas supply at a location external to the appliance.

Do not use this boiler if any part has been under

•

water. Immediately call a qualiﬁed service techni-

cian to inspect the boiler and to replace any part of the control system and any gas control that has been under water.

Combustion air —

• DO NOT install combustion air intake where there

is a risk of combustion air contamination.

Carbon monoxide detector —

• For Direct Exhaust units, a carbon monoxide detec- tor is required in the boiler room. The carbon monoxide detector must be wired on the same electrical circuit as the boiler.

• For

Boiler water —

• Thoroughly ﬂush the system (without boiler con-

• Do not use petroleum-based cleaning or sealing

•

Freeze protection uids —

• NEVER use automotive or standard glycol antifreeze.

Direct Vent units, a carbon monoxide detector

that is wired on the same electrical circuit as the boiler is strongly recommended.

nected) to remove sediment. The high-efﬁciency heat exchanger can be damaged by build-up or corrosion due to sediment.

compounds in boiler system. Gaskets and seals in the system may be damaged. This can result in substantial property damage.

Leaks in boiler or piping must be repaired at once to prevent make-up water. Use this boiler ONLY in a closed-loop system. Continual fresh make-up

water will reduce boiler life. Mineral buildup in heat exchangers reduces heat transfer, overheats the materials, and causes failure. Addition of oxygen carried in by make-up water can cause internal corrosion.

Do not add cold water to hot boiler. Thermal shock

can cause heat exchanger to crack.

Use only freeze-protection ﬂuids made for hydronic systems. Follow all guidelines given by the antifreeze manufacturer. Thoroughly clean and ﬂush any replacement boiler system that has used glycol before installing the new boiler.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Prepare boiler location

Installations must follow these codes:

• Local, state, provincial, national codes, laws, regulations and ordinances.

• NationalFuelGasCode,ANSIZ223.1-latestedition.

• StandardforControlsandSafetyDevicesforAutomaticallyFiredBoil-

ers, ANSI/ASME CSD-1, when required.

• NationalElectricalCode.

• ForCanadaonly:B149.1orB149.2InstallationCodeandCSAC22.1

Canadian Electrical Code Part 1 and any local codes.

The GV90+ boiler gas manifold and controls met safe lighting and other performance criteria when boiler underwent tests speciﬁed in ANSI Z21.13 — latest edition.

For the Commonwealth of Massachusetts, read and follow

the special instructions located on page 34 of this manual.

Install the boiler so control system components are protected

from dripping or spraying water or rain

Allowing these components to become wet could cause a boiler failure, resulting in severe personal injury, death or substantial property damage.

during operation.

High altitude installations

GV90+ boiler controls automatically reduce input with increasing altitude. See Figure 1 for estimated input at altitude as a percentage of sea level input. Multiply the boiler sea level input by this percentage to obtain the estimated high altitude input. Note that the length of the venting system will also have a minor impact on input. Refer to the vent supplement for further information.

No modiﬁcations to the boiler should be necessary for installations up to 5,500 feet above sea level. For higher elevations, the air pressure switch must be changed to a special high altitude switch. Refer to the high altitude kit instructions, page 10. Note that the gas valve outlet pressure must be checked (and adjusted if necessary) following instructions on page 62.

Figure 1 Estimated GV90+ input at altitude

Altitude

(feet)

1,000 97 2,000 93 3,000 90 4,000 87 5,000 83 5,500 82 6,000 80 7,000 77 8,000 74 9,000 72

10,000 69

Figure 2 Service clearances (recommended)

% Sea level input

DO NOT sidewall vent DIRECT EXHAUST APPLICATIONS

at altitudes above 5,500 feet. Sidewall venting is only allowed for DIRECT VENT applications (ducted combustion air) at altitudes above 5,500 feet.

Vent length also affects boiler input — the boiler automati-

cally derates to compensate for pressure loss through the vent. See the derate values given in Figure 109, page 101. For high altitude installations, multiply the % in Figure 1 times the value shown in Figure 109 to determine input vs sea level.

Service clearances

When possible, install GV90+ boilers with clearances at least as large as shown in Figure 2 for best service access.

Flooring

The GV90+ boiler is approved for installation on combustible ﬂooring, but must never be installed on carpeting.

Do not install boiler on carpeting even if foundation is used.

Fire can result, causing severe personal injury, death or substantial property damage.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Prepare boiler location (continued)

Foundation

Provide a solid brick or concrete foundation pad if any of the following is possible:

• When the ﬂoor can become ﬂooded.

• When the boiler mounting area is not level.

• When a high-proﬁle condensate pump is used, provide a foundation

high enough that the GV90+ condensate connection is at least as high as the condensate pump inlet connection.

Figure 3

GV90+3 / GV90+4 16 30¾ 2

GV90+5 / GV90+6 16 37¾ 2

* Increase height if needed to ensure condensate trap outlet tee is above inlet of condensate pump, when used.

Minimum foundation dimensions (inches)

Boiler model W L H *

Residential garage installation

Figure 4 Minimum clearances — when

clearances are less than recommended service clearances of Figure 2, page 6, install as shown below:

A Area adjacent to access door must be accessible

and must allow for removal of the GV90+boiler for service. No other appliance or air mover (exhaust fan, etc.) may be mounted in the same space.

B Access DOOR with fresh air openings C Provide (2) Fresh air openings — Each with at

least 1 sq. inch per 1,000 Btuh of boiler input

Precautions

Take the following special precautions when installing the boiler in a residential garage. If the boiler is located in a residential garage, per ANSI Z223.1, paragraph 5.1.9:

• Mount the boiler a minimum of 18 inches above the oor of the garage to assure the burner and ignition devices will be no less than 18 inches above the ﬂoor.

• Locate or protect the boiler so it cannot be damaged by a moving vehicle.

Minimum clearances

You can install GV90+ boilers in spaces smaller than Fig-

ure 2, page 6 recommended service clearances, but never smaller than shown in Figure 4.

Installations with clearances less than shown in Fig-

ure 2, page 6 must have air openings sized and located as shown in Figure 4.

• Always provide at least screwdriver clearance to jacket front panel screws for removal of front panel for inspection and minor service.

• If the boiler cannot be serviced in place, pipe the boiler with unions and isolation valves so it can be slid out of the space and serviced in an adjacent area.

• The space has to be equipped with a door so boiler can be accessed, unpiped and removed.

NOTICE SPECIAL REQUIREMENTS

FOR AIR OPENINGS

with clearances less than recommended service clearances (Figure 2, page 6), but

no less than shown in Figure 4 — An

access door must be provided, ﬁtted with two air openings as shown in Figure 4. Each opening must have a free area no less than 1 square inch per 1000 Btuh input of the GV90+ boiler in the space.

DO NOT apply the air opening sizes given in Figure 42, page 36 or Fig-

ure 60, page 50

: For installations

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Prepare the boiler (continued)

Check oriﬁce plate — replace if necessary

The correct orice plate must be used. Failure to do so

will result in severe personal injury, death or substantial property damage. The boiler is shipped with a natural

gas orice plate. It MUST BE CONVERTED to use propane.

Natural gas:

For natural gas installations, inspect the silver gas/air orice plate

marking

stamped with another size, obtain the correct plate from your wholesaler. The boiler size is stamped where the “X” is shown in the plate stamping, Figure 6.

Propane:

For propane installations, replace the silver gas/air orice plate

with the red/white plate

white plate boiler size is correct for the GV90+ boiler being installed. The boiler size is stamped where the “X” is shown in the plate stamping, Figure 6.

Also ﬁll out the propane label in the conversion kit and attach to the left side of the jacket, above the gas inlet opening, as shown in Figure 5.

Orice plate installation, when required

Access the bottom of the blower housing as shown in Figure 5.

. It must be the same as the boiler size. If the oriﬁce plate is

, per following instructions. Ensure the red/

Figure 5 Check for correct gas oriﬁce plate

A Remove jacket front

panel to access the bottom side of the blower housing.

B Complete the propane

conversion label included with the conversion kit. Install label on jacket left side, as shown.

Leave the boiler on its back, on the skid as shown, until you have checked the gas/air oriﬁce plate and replace it if necessary.

Figure 6 Follow instructions to check or replace

gas oriﬁce plate ("X" = boiler size)

To inspect the plate only,

read the marking on the plate edge. It

must read the same as the boiler size and fuel, as follows:

Boiler model Natural gas marking Propane marking

GV90+3 NG 3 SEC LP 3 SEC GV90+4 NG 4 SEC LP 4 SEC GV90+5 NG 5 SEC LP 5 SEC GV90+6 NG 6 SEC LP 6 SEC

To replace the plate, using a manual screwdriver or nut driver, see Figure 6:

1. Loosen screws

2. Remove screws

1 and 2 two full turns.

3 and 4.

3. Pull the gas/air oriﬁce plate forward to remove it.

4. Slide in the new plate as shown in Figure 6. The

propane plate must go next to the blower housing

5. Replace screws

3 and 4. Tighten all four screws securely and uni-

red side of a

formly. DO NOT overtighten. DO NOT exceed 40 inch-pounds torque.

6. Bend down plate label tab at score mark as shown in lower right corner of Figure 6, item 10.

DO NOT use electric or pneumatic screwdrivers to re-

move or tighten the gas/air boss screws. Hand-tighten only, using manual screwdriver. Should the torque exceed 40 inch-pounds, the threaded holes could strip out, causing an inadequate seal of the oriﬁce plate. Failure to properly seal the plate to the housing could result in a gas leak, causing severe personal injury, death or substantial property damage.

1–4 Screws — follow instructions for loosening and tightening

5 Gas/air manifold 6 Front section, bottom view, component details omitted 7 Side shown must point toward air inlet hose — WARNING

label side for natural gas; WHITE side for propane gas

8 Propane oriﬁce plate, RED one side and WHITE on the

other (red side must face the blower housing

9 Natural gas oriﬁce plate, SILVER 10 Oriﬁce plate after bending along score mark — label is

visible when installed

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Prepare the boiler (continued)

Install condensate trap

1. Before placing the boiler in position, install the condensate trap line, shown in Figure 7. Items shown are provided with the boiler.

Step 1 Attach the ﬂue drain hose (C) to the in-line ﬂue drain

nipple (B).

Step 2 Slide a screw driver or pencil through the condensate

drain nipple (G).

Slide the end of the screwdriver or pencil into the open end of the ﬂue drain hose (C).

Feed the in-line ﬂue drain (A) assembly into the ﬂue connection (D), guiding the ﬂue drain hose through the condensate drain nipple (G) with the screwdriver or pencil.

Step 3 Press the in-line ﬂue drain (A) into the ﬂue connection

(D) and through the seal ring until it reaches the stop. Then tighten the ﬂue connection hose clamp to secure.

The ﬂue drain hose (C) should now extend down past the end of the condensate drain nipple (G).

Step 4 Slide the U-clamp (F) over the condensate trap tee (E)

and into the two holes in the rail. Attach the two nuts provided to the U-clamp and tighten to secure the condensate trap tee to the rail.

Step 5 Slide the ends of the condensate trap hose (H) onto the

condensate drain nipple (G) and the condensate trap tee (E). Secure the condensate trap hose at each end with the hose clamps (J).

Check the height of the condensate trap tee outlet.

Before rotating the boiler into position, measure the distance from the condensate tee outlet to the bottom of the boiler mounting rails. When the boiler is place in position, the condensate tee outlet must be higher than the condensate pump inlet connection (when a condensate pump is used). Increase the foundation height if necessary.

Figure 7 Install condensate trap

A In-line ﬂue drain B Flue drain nipple C Flue drain hose D Flue connection E Condensate trap tee F U-clamp and nuts (not

shown)

G Condensate drain

nipple

H Condensate trap hose J Hose clamps

Finished assembly

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Prepare the boiler (continued)

Install high altitude air pressure switch when required (only above 5,500 feet)

1. For installations at altitude more than 5,500 feet above sea level: a. A special high altitude air pressure switch is required. b. The gas valve outlet pressure setting must be checked, and

adjusted if necessary, per the instructions on page 62.

Failure to check gas valve outlet pressure and adjust, if

necessary, could result in severe personal injury, death or substantial property damage. Carefully follow the guidelines given in this manual.

2. Obtain the GV90+ high altitude kit from your local Weil-McLain distributor. The high altitude kit contains the high altitude air pressure switch.

3. See Figure 8 (switch shown with wires removed). a. Remove the two (RED) control wires from the air pressure

switch spade terminals.

b. Remove the factory-installed air pressure switch (loosen top

screw and remove bottom screw holding switch to jacket interior panel).

c. Install the high altitude air pressure switch in the same loca-

tion.

d. Carefully replace the hoses on the new switch, with the red hose

on the hose barb closest to the electrical spade connectors, as shown in Figure 8. The white hose goes on the other hose barb.

e. Replace the two (RED) control wires on the new pressure

switch spade terminals.

Figure 8 Air pressure switch mounting

1 Interior panel top 2 Jacket left side panel 3 Air pressure switch

4 WHITE hose 5 RED hose

6 Mounting screws

Figure 9 Follow instructions to perform the steps

shown below

Rotate the boiler into position

Boiler is shipped on back side. It must be taken off skid

and rotated into correct position.

After installing condensate line, inspecting (replacing if necessary) the gas/air oriﬁce and installing the high altitude kit (if required), move the boiler near its position.

Figure 9 shows the boiler with the front and top panels replaced. These panels may be left off if desired until the installation has been completed.

Boiler is heavy and contains some sheet metal parts which

may have sharp edges. Wear gloves when handling and take proper precautions when moving. Failure to do so will result in severe personal injury, death or substantial

property damage.

Refer to Figure 9 for placement sequence as follows:

1 Wear heavy gloves — carefully rotate the boiler over onto its

base rail legs.

2 Clip the shipping strap securing the skid to the boiler block as-

sembly. Remove the skid and strap.

3 Attach the jacket rear panel as shown using (4) #10 x ½” screws

provided in the accessory bag.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Prepare the boiler (continued)

Perform hydrostatic pressure test

Pressure test boiler before attaching water or gas piping (except as noted below) or electrical supply. Remove jacket top panel before proceeding.

Use two wrenches when tightening water piping at

boiler

, using one of the wrenches to prevent the boiler interior piping from turning. Failure to support the boiler piping connections to prevent them from turning could cause damage to boiler components.

Prepare boiler for test — see Figure 10

Step 1 Connect a hose from water supply to ﬁll and drain boiler

for hydrostatic test. Hose is not included with boiler.

Step 2 Connect hose to boiler drain valve. Make sure hose can

also be used to drain boiler after test.

Step 3 Remove 1" nipple, 1" tee, bushing and pressure/tempera-

ture gauge from accessory bag. Pipe to boiler supply connection as shown. Use pipe dope sparingly.

Step 4 Connect a nipple and shutoff valve to system supply

connection on the 1" tee. This valve will be used to bleed air during the ﬁll. Valve and nipple are not included with boiler.

Step 5 Connect a nipple and shutoff valve to system return

connection at circulator ﬂange. This valve will be used to bleed air during the ﬁll. Valve and nipple are not included with boiler.

Figure 10 Piping connections for hydrostatic test

Step 6 Install a ¾" pipe plug in the relief valve opening, top of

the rear boiler section, as shown. Plug is not included with boiler.

Fill and pressure test

1. Connect ﬁll water supply through drain valve, item 2.

2. Fill boiler with water (be sure bleed valves at 4 and 5 are open).

3. When water flows from bleed valves, shut off water at drain valve.

4. Close bleed valves.

5. Slowly reopen drain valve (item 2) until test pressure of 45 PSIG (or 1.5 times boiler relief valve setting — NEVER MORE than 75 PSIG) is reached on the pressure gauge.

6. Test at this pressure for no more than 10 minutes.

Do not leave boiler unattended. A cold water ﬁll could

expand and cause excessive pressure, resulting in severe personal injury, death or substantial property damage.

7. Make sure constant gauge pressure has been maintained throughout test. Check for leaks. Repair if found.

Leaks must be repaired at once. Failure to do so can dam-

age boiler, resulting in substantial property damage.

Do not use petroleum-based cleaning or sealing com-

pounds in boiler system. Severe damage to boiler will occur, resulting in substantial property damage.

Drain and remove ttings

1. Disconnect ﬁll water hose from water source.

2. Drain boiler at drain valve or out hose, whichever provides best access to drain. Close drain valve and remove hose after draining.

3. Remove nipples and valves at 4 and 5 unless they will remain for use in the system piping.

4. Remove plug (item 6) from relief valve tapping.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Install water piping

Use two wrenches when tightening water piping at

boiler

, using one of the wrenches to prevent the boiler interior piping from turning. Failure to support the boiler piping connections to prevent them from turning could cause damage to boiler components.

The cast iron heat exchanger return temperature must

be kept at or above 140°F during all times of operation to prevent possibility of corrosion due to condensation. This is done automatically, using the boiler's internal circulators. DO NOT remove or tamper with these circulators. Failure to comply could result in severe personal injury, death or substantial property damage.

General piping information

Minimum pipe size for boiler loop piping

Figure 11 Provide boiler loop piping no smaller than listed

below (based on 20°F temperature rise)

Boiler loop pipe size, Minimum

GV90+3 or 4 1”

GV90+5 or 6 1¼”

Additional limit controls

Following standard industry practices, if installation is to comply with ASME or Canadian requirements, an additional high temperature

limit

may be needed. Consult local requirements for other codes/

standards to determine if needed. Wire as shown in Figure 67, page 56.

• Install a manual reset high temperature limit between the boiler and the isolation valve.

• Wire the manual reset limit in series with the boiler limit control.

• Set the manual reset limit control at least 20°F above the boiler limit control setting (maximum setting 220°F).

Air separator

Install an air separator in the piping as shown in this manual. For single-zone systems, install the air separator in the return piping as shown in Figure 14, page 14. This allows mounting the automatic air vent and expansion tank off of the separator.

Install relief valve

1. Install relief valve ONLY as shown in Figure 12.

2. Connect discharge piping to safe disposal location, following guidelines in Figure 13, page 13.

Figure 12

Install and pipe relief valve

Low water cut-off, when required

A low water cutoff device is required when boiler is installed above radiation level or by certain state or local codes or insurance companies. Use low water cutoff designed for water installations. Electrode probetype is recommended. Purchase and install in tee in supply piping above boiler. Wire contact as shown in Figure 67, page 56.

If boiler is connected to heating coils located in air han-

dling units where they can be exposed to refrigerated air, use ﬂow control valves or other automatic means to prevent gravity circulation during cooling cycle. Circulation of cold water through the boiler could result in damage to the heat exchanger, causing possible severe personal injury, death or substantial property damage.

Backow preventer

Where required by codes, install a backow preventer in the cold water ﬁll line, as shown in suggested piping diagrams on following pages. Install a check valve if a backﬂow preventer is not installed.

Legend

1 Jacket plug for unused relief valve jacket open-

ing.

2 Jackets are provided with two relief valve open-

ings because each jacket size is used for two boiler sizes. Cover the unused opening with the plug

provided. 3 Boiler relief valve (from accessory bag) 4 ¾” x 3” nipple, provided in accessory bag 5 ¾” relief valve tapping in back section 6 Connect minimum ¾” discharge piping to relief

valve.

See Figure 13, page 13.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Install water piping (continued)

Figure 13 Relief valve installation guidelines

To avoid water damage or scalding

due to relief valve operation, as per local or state codes

Discharge line must be connected

to relief valve outlet and run to a safe place of disposal. Terminate the discharge line in a manner that will prevent possibility of severe burns or property damage should the valve discharge.

Discharge line must be as short as

possible and be the same size as the valve discharge connection throughout its entire length.

Discharge line must pitch downward

from the valve and terminate at least 6” above the ﬂoor drain where any discharge will be clearly visible.

The discharge line shall terminate

plain, not threaded, with a material serviceable for temperatures of 375°F or greater.

Do not pipe the discharge to any

place where freezing could occur.

No shutoff valve shall be installed

between the relief valve and boiler, or in the discharge line. Do not plug or place any obstruction in the discharge line.

Test the operation of the valve after

ﬁlling and pressurizing system by lifting the lever. Make sure the valve discharges freely. If the valve fails to operate correctly, replace it with a new relief valve.

Failure to comply with the above

guidelines could result in failure of the relief valve to operate, resulting in possibility of severe personal injury, death or substantial property damage.

Expansion tank

Figure 14, page 14 and Figure 15, page 14 show typical installation of the expansion tank. Always locate the air separator and expansion tank as shown in the suggested piping drawings, beginning with Figure 17, page 16.

Ensure that the expansion tank size will handle boiler and system water volume and temperature. See tank manufacturer’s instructions and ratings for details. Additional tanks may be added to the system if needed to handle the expansion. These tanks may be installed by connecting to tees in the system piping.

Undersized expansion tanks cause system water to be lost

from the relief valve and makeup water to be added through the ﬁll valve. Eventual section failure can result. Always locate the cold water ll connection at the expansion tank. Never locate this elsewhere in the system.

Diaphragm- or bladder-type tank:

Refer to Figure 14, page 14 for suggested piping when using a diaphragmor bladder-type expansion tank.

Diaphragm- or bladder-type expansion tank — Control

ll pressure with the tank air charge pressure. Always check

pressure and charge tank with tank removed fr om system to be sure reading is accurate. Boiler relief valve is set for 30 PSIG. Operating pressure of system, after temperature expansion above cold ﬁll pressure, should not exceed 24 PSIG to avoid weeping of relief valve.

Install an manufacturer’s instructions.

Closed-type expansion tank:

Figure 15, page 14 shows suggested piping when using a closed-type expansion tank, in which the air is directly in contact with tank water.

Connect piping (½” or ¾”) from the air separator top outlet to the tank ﬁtting. Slope any horizontal piping a minimum of 1 inch per 5 feet of horizontal pipe.

Always use a (shown). The ﬁtting reduces gravity ﬂow of water in the piping to the tank, avoids air bubbling through the tank water, and provides the proper ﬁll height in the tank.

automatic air vent on top of the air separator, per separator

tank tting, such as the B&G Tanktrol or Taco Taco-Trol

Correct all leaks in the system or tank piping. Leaks allow

air to escape from the system and will cause water-logging of the tank. This will result in water loss through the boiler relief valve due to over-pressurization.

NEVER use an automatic air vent in a system equipped with a

closed-type expansion tank. The air removed from the system will cause water-logging of the expansion tank.

Closed-type expansion tank — Follow tank manufacturer’s

instructions for lling the tank. Typical tank sizing provides for approximately 12 PSIG when the tank is ﬁlled to the normal level and system water is cold. Note that boiler relief valve is set for 30 PSIG. Operating pressure of system, after temperature expansion above cold ﬁll pressure, should not exceed 24 PSIG to avoid weeping of relief valve.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Install water piping (continued)

Figure 14 Piping to single-zone system using diaphragm- or

bladder-type expansion tank. Boiler connections are 1” NPT (supply from 1” tee, return to 1” recuperator ﬂange).

Figure 15 Piping closed-type expansion tank

Pipe diaphragm- or bladder-type expansion tanks to the bot-

tom of the separator.

Pipe closed-type (air in contact with water) tanks to the top of

the air separator. Always connect the ﬁll line to the expansion tank location, as shown above and in the suggested piping.

1 Relief valve discharge piping — see page 12 2 Isolation valves 3 Fill valve 4 Diaphragm-type expansion tank — always locate as

shown in the suggested piping drawings in this manual

5 Air separator

• provide with automatic air vent ONLY when used with diaphragm-type expansion tanks

• pipe air outlet to expansion tank when used with close-type tanks

Legend

6 Cold ﬁll line, with backﬂow preventer or check valve

when required by codes (see Figure 15 for typical components)

7 System supply piping 8 System return piping 10 Pressure reducing valve, when used 11 Quick-ﬁll bypass valve, when used 12 Closed-type expansion tank — always locate as shown

in the suggested piping drawings in this manual

13 Tank ﬁtting

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Install water piping (continued)

System water piping methods

Most piping methods shown in this manual use

primary/secondary connection to the boiler loop. These designs ensure proper flow through the GV90+ boiler, for the most efﬁcient and reliable operation of the boiler and the heating system. For other piping methods, consult your local WeilMcLain representative.

Circulators

Do not remove either of the GV90+ internal pumps

for use elsewhere in the system. Both pumps are required for proper operation. Removing a pump will cause the boiler to malfunction. Substantial property damage could result.

Failure to comply could result in unreliable perfor-

Circulator ow rate

Size system circulators based on the ﬂow rate required to achieve the temperature change needed. You can closely estimate temperature rise (or drop) through a circuit by using the following formula, where TD is temperature rise (or drop), FLOW is ﬂow rate (in gpm), and BTUH is the heat load for the circuit:

Examples:

Consider a system loop for a system with total heating load equal to 210,000 Btuh. The desired temperature drop through the system piping is 20°F. Then the required ﬂow rate is:

FLOW =

SIMPLIFIED: For 20° temperature drop, FLOW = MBH / 10.

Circulator head requirement

The circulator must be capable of delivering the required ﬂow against the head loss that will occur in the piping. Determine the pipe size needed and the resultant head loss using accepted engineering methods. The simpliﬁed pipe sizing here is limited to residential systems, and does not include systems with fan coil units or radiant tubing.

Never install another pump in series with the GV90+ boiler

. Forced ﬂow can cause improper operation of the boiler controls. Substantial property damage could result.

mance and nuisance shutdowns from insufﬁcient ﬂow.

BTUH

FLOW =

—–—–—–—–

TD x 500

210,000

—–—–—–—–

= 21 gpm

20 x 500

The following simpliﬁed method for pipe and cir-

culator sizing must be limited to residential applications using baseboard (ﬁnned or cast iron), cast iron radiators or convectors. DO NOT apply for radiant heating, fan coil units or commercial installations.

Simpliﬁed pipe/circulator selection

1. Install the boiler and piping using the recommended piping layouts in this manual.

2. Size the piping and components for each circuit in the space heating system using Figure 16.

head loss in all piping will be 0.04 feet per foot of pipe.

a. Determine the heating load (Btuh) for each circuit. b. Calculate the ﬂow rate for each circuit using its load. To use a 20°F temperature drop, just divide the

MBH (1,000’s of Btuh) by 10. Example — Flow for 20°F temp drop with 35,000 Btuh: FLOW = 35 MBH / 10 = 3.5 gpm

c. Find the pipe size in Figure 16 that has a max ﬂow rate

just larger than that required for the circuit. d. Find the total equivalent length (TEL) of the circuit. TEL accounts for losses through ﬁttings and valves by

using the equivalent length of pipe that would cause

the same head loss. Add these numbers to the measured

length of the circuit to ﬁnd TEL in feet.

TEL is usually close to 1.5 times the length of the

circuit for residential baseboard, radiator or conv ec-

tor applications.

e. Measure the length of each circuit from the circulator

outlet back to its inlet. Then multiply this length times

1.5 to get the approximate TEL of the circuit.

f. Find the head loss for each circuit:

TEL = 1.5 X Circuit Length (feet) HEAD = TEL X 0.04 (feet water column)

g. NOTE: Size system header piping for the total ﬂow of

all connected zones.

3. Example: a. For a circuit with heating load = 45,000 Btuh (= 45

MBH). Measured length of circuit is 88 feet. b. Flow = 45 MBH / 10 = 4.5 gpm. c. TEL = 1.5 x 88 feet = 132 feet. d. From Figure 16, select 1" pipe (max ﬂow = 8 gpm). e. Head loss = TEL x 0.04 = 132 x 0.04 = 5.28 feet. f. Select a circulator that can deliver at least 4.5 gpm at a

head of 5.28 feet. (Read the NOTICE below.)

To use this method, limit the ﬂow through ¾"

ﬁnned-tube baseboard to 3.9 gpm, or use 1" baseboard and limit ﬂow to 7.1 gpm. If the total load of the circuit requires more ﬂow, split the circuit into two or more.

Figure 16

Pipe size

(inches)

Flow rates for 0.04 feet head loss per foot of

copper pipe

MAX Flow rate (GPM)

@ 0.04 feet per foot

1 1¼ 1½

(based on water at140°F)

8 14 22

At the ow rates listed, the

Pipe size

(inches)

2½

3 4

MAX Flow rate (GPM)

@ 0.04 feet per foot

75 140 290

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Install water piping (continued)

Baseboard system piping — CIRCULATOR zoning (primary/secondary)

Apply Figure 17 for circulator zoning on systems using baseboard heaters. The heaters can be any baseboard style, including ﬁnned tube or cast iron.

Zoning with circulators — The GV90+ internal system

circulator cannot be removed from the boiler for use as one of the zone circulators. It must remain as shipped from the factory to allow proper ﬂow control inside the boiler. You will need a circulator for each zone. Provide circulator relays or circulator zone controller.

Baseboard system piping — ZONE VALVE zoning (direct connection)

The boiler internal circulator can be used to circulate many zone-valve zoned systems as shown in Figure 18, page 17 for application on systems using baseboard (ﬁnned tube or cast iron).

• DO NOT apply this piping when using a GV90+6 — the internal

circulator cannot supply enough ow to the system

• When applying Figure 18, page 17, DO NOT exceed the limits

shown in Figure 19, page 17

• For systems requiring higher ow or head loss, apply the

suggested piping of Figure 20, page 18, NOT that of Figure 18, page 17.

Balancing, when required

—

Substitute a memory-stop valve for one of the isolation valves in each zone to use the memory-stop valve for balancing ﬂow as well as isolation.

Zoning with zone valves —

Provide a separate 24-volt transformer to power the zone valves. Size the transformer to handle the total rated load of all connected zone valves. Alternatively, use a zone valve zone controller.

Applying Figure 18, page 17

1. Figure 18, page 17 and Figure 19, page 17 provide guidelines for checking whether the GV90+ internal circulator can provide sufﬁcient ﬂow when directly connected to a two-pipe baseboard system.

The outputs of GV90+ boilers are all too high for con-

nection to a single-loop series-loop system. To apply to an existing series loop system, the system must be ﬁtted with trunk lines to convert to a split-loop system. Provide either one or two trunk lines to meet the minimum number of circuites and maximum loading per circuit given in Figure 19, page 17.

2. The system pipe sizing must be no smaller than shown in the Legend for Figure 18, page 17.

3. Values shown for maximum circuit lengths, maximum load per circuit and the maximum feet baseboard per circuit are limits that ensure the internal circulator will have sufﬁcient head to provide the ﬂow needed for each circuit.

Figure 17 Baseboard system — circulator zoning

MINIMUM

Boiler loop pipe size

GV90+3/4 GV90+5/61”1¼”

Legend

1 Isolation valves

2 Automatic air vent (with

diaphragm-type expansion tank), or connect to tank ﬁtting (closed-type expansion tank).

3 Diaphragm- or bladder-

type expansion tank, if used. (For closed-type expansion tank, pipe from top of air separa-

tor to tank ﬁtting as in Figure 15, page 14.)

5 Zone circulator

6 Flow/check valve

7 Hose bibb purge valve

8 Boiler pressure/tempera-

ture gauge

16 Cold water ﬁll line — see

Figure 15, page 14 for typical components

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Install water piping (continued)

Figure 18 Zone valve zoning — GV90+3, GV90+4 or GV90+5

(DO NOT apply to GV90+6)

Legend

1 Isolation valves

2 Automatic air vent (with

diaphragm-type expansion tank), or connect to tank ﬁtting (closed-type expansion tank).

3 Diaphragm- or bladder-

type expansion tank, if used. (For closed-type expansion tank, pipe from top of air separator to tank fitting as in Figure 15, page 14.)

4 Zone valve

7 Hose bibb purge valve

8 Boiler pressure/tempera-

ture gauge

10 Differential pressure by-

pass valve

16 Cold water ﬁll line — see

Figure 15, page 14 for typical components

Pipe sizes (NPT), minimum

Boiler model

GV90+3 GV90+4

GV90+5 1¼" ¾"

Mains

1" ¾"

Circuit requirements

See Figure 19

One-pipe diverter tees systems

plication information on this page is based on two-pipe baseboard systems.

whether the internal circulator can provide sufficient flow to a one-pipe diverter tee system, use the available head value given in Figure 19, page 17.

Circuits

— The ap-

To check

Figure 19 The system must meet the following requirements when applying Figure 18

Boiler

model

GV90+3

GV90+4

GV90+5

GV90+6 DO NOT apply to GV90+6 — Use primary/secondary piping ONLY, as in Figure 20, page 18.

* This application may be marginal. It could cause temperature distribution problems, because the temperature drop is 30°F,

NOT 20°F. The best method is to use primary/secondary piping for the GV90+5 as in Figure 20, page 18.

Part number 550-142-054/1211

Circulator HEAD

available to the

system

6.4 feet w.c. @ 6.5 GPM

4.1 feet w.c. @ 9.7 GPM

5.5 feet w.c.

@8.7 GPM

Maximum

circuit length

103 feet 2 40 MBH 67 feet

92 feet 3 33 MBH 55 feet

112 feet 3 53 MBH 88 feet

Minimum

number

of circuits

Max load

of any circuit

Max feet baseboard

of any circuit

(@ 600 Btuh/foot)

Summary

6.5 GPM total

(max 4GPM any cricuit)

20°F temperature drop

9.7 GPM total

(max 3.3 GPM any circuit)

20°F temperature drop

8.7 GPM

(max 3.5 GPM any circuit)

30°F temperature drop

GV90+ gas-fired water boiler — Boiler Manual

Install water piping (continued)

Radiator system piping

Apply Figure 20 (zone-valve zoning) or Figure 21 (circulator zoning) to systems using standing cast iron radiators. This applies to gravity water systems and converted steam systems using columnar, tubular or recessed cast iron radiators.

The suggested piping for zone-valve zoning radiator systems differs from baseboard systems because of the high water content of cast iron radiators. The GV90+ internal circulators automatically regulate supply and internal bypass ﬂow based on the temperature of the water returning to the boiler. At the start of many heating cycles in a radiator system, the water in the radiators is cool. So the boiler would slow down system ﬂow rate while sending out relatively hot water. This could cause heat distribution problems. Install a separate system circulator as shown in Figure 20 when zoning with zone valves. The separate circulator assures a relatively constant temperature drop through the system.

The boiler internal circulators must be left in the boiler. They cannot be removed for use a zoning circulator. Provide a circulator for each zone when circulator zoning, and pipe the system as in Figure 21.

Balancing, when required

valve for one of the isolation valves in each zone to use the memory-stop valve for balancing ﬂow as well as isolation.

Zoning with zone valves —

transformer to power the zone valves. Size the transformer to handle the total rated load of all connected zone valves. Alternatively, use a zone valve zone controller.

—

Substitute a memory-stop

Provide a separate 24-volt

Figure 20 Radiator system — zone-valve zoning

(0ptional)

MINIMUM

Boiler loop pipe size

GV90+3/4 GV90+5/61”1¼”

Zoning with circulators — The GV90+ internal system

The system circulator must be supplied by the in-

staller.

Legend

1 Isolation valves 2 Automatic air vent (with diaphragm-type expansion tank), or

connect to tank ﬁtting (closed-type expansion tank).

3 Diaphragm- or bladder-type expansion tank, if used. (For closed-

type expansion tank, pipe from top of air separator to tank ﬁtting

as in Figure 15, page 14.) 4 Zone valve 5 System or zone circulator 6 Flow/check valve 7 Hose bibb purge valve 8 Boiler pressure/temperature gauge 9 System supply temperature gauge 10 Differential pressure by-pass valve 16 Cold water ﬁll line — see Figure 15, page 14 for typical components

Figure 21 Radiator system — circulator zoning

MINIMUM

Boiler loop pipe size

GV90+3/4 GV90+5/61”1¼”

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Install water piping (continued)

Single-zone radiant heating or heat pump

Radiant heating systems and heat pump systems usually require system supply water temperatures below 140°F. But the boiler outlet water temperature will be at least 150°F to 160°F during most operating conditions. So the piping must include a method of reducing the supply water temperature to the system.

Figure 22 uses two balancing valves to manually adjust the supply water temperature. Follow the instructions below to adjust these valves. Install

the supply temperature limit control (item 14) as shown to protect the

system from over-temperature conditions. Note also that this piping requires a separate system circulator, as shown, because of the higher ﬂow rates of radiant and heat pump systems.

Manual adjustment of the supply temperature is limited to singlezone systems because multi-zone systems will cause varying loads, making it unlikely an acceptable valve setting could be found. See Figure 23, page 20 or Figure 24, page 20 for multi-zone systems.

You may also apply the suggested piping of either Figure 23, page 20 or Figure 24, page 20 if you want automatic supply temperature regulation or outdoor reset temperature control.

For additional information and alternatives in piping for radiant heating systems, contact Weil-McLain.

Figure 22 Single-zone radiant heating or

heat pump system

MINIMUM

Boiler loop pipe size

GV90+3/4 GV90+5/61”1¼”

The system circulator must be supplied by the in-

staller.

Adjust balancing valves

Use valves 17 and 18 to mix boiler supply water with system return

water, reducing supply water temperature to the system.

1. Subtract the design system supply temperature from 150°F. Call this number the

temperature difference.

2. Open valve 17 and close valve 18.

3. Start the boiler and system.

4. Let the system warm up for about 15 minutes.

5. Note the temperature at gauge 9 (system supply) and gauge 8

(boiler supply).

6. Slowly close valve 17 while opening valve 18 until gauge 9 reads

lower than gauge 8 by at least the temperature difference found

in step 1.

7. Example: For a design supply temperature of 100°F, the

ture difference

would be 150°F minus 100°F, or 50°F. Set the valves

tempera-

until gauge 9 reads at least 50°F lower than gauge 8.

Legend

1 Isolation valves

2 Automatic air vent (with diaphragm-type expansion

tank), or connect to tank ﬁtting (closed-type expansion tank).

3 Diaphragm- or bladder-type expansion tank, if used

(For closed-type expansion tank, pipe from top of air separator to tank ﬁtting as in Figure 15, page 14.)

5 System circulator

7 Hose bibb purge valve

8 Boiler pressure/temperature gauge

9 System supply temperature gauge

10 Return temperature gauge

14 Supply temperature limit control — Set at a tempera-

ture below the maximum allowed for the system or as directed by the system designer.

16 Cold water ﬁll line — see Figure 15, page 14 for typical

components

17 Balancing valve

18 Balancing valve

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Install water piping (continued)

Multi-zone radiant heating system

Multi-zone systems require automatic regulation of the system supply temperature because of widely varying load conditions. Figure 23 (zone-valve zoning) and Figure 24 (circulator zoning) show suggested piping for these systems.

Provide an automatic temperature control valve or

motor-operated valve which can be adjusted for the desired supply water temperature. This is required to protect the radiant system from excessive temperature.

Zone-valve zoning — The suggested piping uses a separate circulator for system circulation to provide the higher ﬂow typical of radiant heating systems and to assure good temperature distribution in the system when the return water temperature is low.

Circulator zoning — The GV90+ internal circulators must not be removed. Provide a separate circulator for each zone.

Balancing, when required

valve for one of the isolation valves in each zone to use the memory-stop valve for balancing ﬂow as well as isolation.

Zoning with zone valves —

transformer to power the zone valves. Size the transformer to handle the total rated load of all connected zone valves. Alternatively, use a zone valve zone controller.

Zoning with circulators — The GV90+ internal system

tem circulator must be supplied by the installer.

Outdoor reset

Apply Figure 23 or Figure 24 for any system intended for outdoor reset of the supply water temperature. Use a motor-operated three-way valve and an outdoor reset temperature control system.

—

Substitute a memory-stop

Provide a separate 24-volt

Figure 23 Auto system supply temp regulation —

zone valve zoning

MINIMUM

Boiler loop pipe size

GV90+3/4 GV90+5/61”1¼”

Figure 24 Auto system supply temp regulation —

circulator zoning

Legend

1 Isolation valves 2 Automatic air vent (with diaphragm-type expansion tank), or

connect to tank ﬁtting (closed-type expansion tank).

3 Diaphragm- or bladder-type expansion tank, if used (For closed-

type expansion tank, pipe from top of air separator to tank ﬁtting

as in Figure 15, page 14.) 4 Zone valve 5 System or zone circulator 6 Flow/check valve 7 Hose bibb purge valve 8 Boiler pressure/temperature gauge 9 System supply temperature gauge 10 Supply temperature automatic mixing valve 11 Differential pressure by-pass valve 16 Cold water ﬁll line — see Figure 15, page 14 for typical components

MINIMUM

Boiler loop pipe size

GV90+3/4 GV90+5/61”1¼”

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Install water piping (continued)

Piping snow melt systems or combination snow melt/space heating systems

Combination snow melt/space heating systems can have return water temperature below 60°F, and the return temperature will ﬂuctuate. So these systems require automatic return water temperature as shown in Figure 25 (zone-valve zoning) or Figure 26 (circulator zoning).

Select an automatic temperature control valve or motor-operated valve which can be adjusted to provide a return water temperature of at least 60°F. Any setting higher than 60°F will also be acceptable.

Zone-valve zoning — The suggested piping uses a separate circulator for system circulation to assure good temperature distribution in the system when the return water temperature is low.

Circulator zoning — The GV90+ internal circulators must not be removed. Provide a separate circulator for each zone.

The return water temperature to the boiler must be

at least 60°F. Provide and apply means to regulate the return temperature. Failure to do so can result in boiler control operation problems, causing possible signiﬁcant property damage.

Zoning with zone valves

diagrams in this section is shown with an isolation valve on each side. Substitute a memory-stop valve for one of these in each zone in order to use the memory-stop valve for balancing ﬂow as well as isolation.

valves. Size the transformer to handle the total rated load of all connected zone valves.

Zoning with circulators — The GV90+ internal system

tem circulator must be supplied by the installer.

ovide a separate 24-volt transformer to power the zone

— Each zone in the piping

The sys-

Figure 25 Auto return temp regulation — circulator

zoning

MINIMUM

Boiler loop pipe size

GV90+3/4 GV90+5/61”1¼”

Figure 26 Auto return temp regulation — zone valve

zoning

Legend

1 Isolation valves 2 Automatic air vent (with diaphragm-type expansion tank), or

connect to tank ﬁtting (closed-type expansion tank).

3 Diaphragm- or bladder-type expansion tank, if used (For closed-

type expansion tank, pipe from top of air separator to tank ﬁtting

as in Figure 15, page 14.) 4 Zone valve 5 System or zone circulator 6 Flow/check valve 7 Hose bibb purge valve 8 Boiler pressure/temperature gauge 9 System supply temperature gauge 10 Return temperature automatic mixing valve 11 Differential pressure by-pass valve 16 Cold water ﬁll line — see Figure 15, page 14 for typical components

Part number 550-142-054/1211

MINIMUM

Boiler loop pipe size

GV90+3/4 GV90+5/61”1¼”

GV90+ gas-fired water boiler — Boiler Manual

Install water piping (continued)

Water chiller systems

Pipe the boiler and water chiller as shown in Figure 27.

Install boiler, as shown, so chilled medium is piped in parallel with heating boiler.

Use appropriate valves to prevent chilled medium from entering boiler. See Figure 27 for typical installation of balancing valve and check valve.

Install the ﬂow/check valve in the boiler supply piping, as shown in Figure 27, to prevent gravity circulation during the cooling cycle.

If boiler is connected to heating coils located in air handling units where they can be exposed to refrigerated air, use ﬂow control valves or other automatic means to prevent gravity circulation during cooling cycle.

Balancing, when required

valve for one of the isolation valves in each zone to use the memory-stop valve for balancing ﬂow as well as isolation.

Zoning with zone valves —

transformer to power the zone valves. Size the transformer to handle the total rated load of all connected zone valves. Alternatively, use a zone valve zone controller.

Zoning with circulators — The GV90+ internal system

—

Substitute a memory-stop

Provide a separate 24-volt

Figure 27 Installing GV90+ boiler in system with

water chiller

MINIMUM

Boiler loop pipe size

GV90+3/4 GV90+5/61”1¼”

Chilled water systems often use closed-type expansion

tanks, as shown in Figure 27. DO NOT install automatic air vents on these systems.

Legend

1 Isolation valves

2 Air separator

3 Expansion tank with tank ﬁtting (piping shown for

application of a closed-type expansion tank)

5 System circulator

6 Flow/check valve

8 Boiler pressure/temperature gauge

16 Cold water ﬁll line — see Figure 15, page 14 for typical

components

17 Balancing valve

19 Chiller

20 Strainer

21 Check valve

22 System supply

23 System return

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Multiple boiler installations

Placing multiple boilers

1. Locate multiple boilers in boiler room according to:

a. Figure 28 (side-to-side), or b. Figure 29 (back-to-back).

2. Provide the clearances indicated in the illustrations listed above to provide for access and servicing. If these recommended dimensions are not possible, provide at least the recommended service clearances given on page 6. Also follow local codes.

3. Construct boiler foundation if boiler room ﬂoor is uneven or if there is a danger of ﬂooding. Size foundation to allow for clearance and spacing dimensions shown in the illustrations at right.

4. Chalkline boiler locations on foundation or boiler room ﬂoor.

5. Uncrate, assemble and mount boilers according to instructions in this manual.

6. Provide clearance for installation of venting, air piping, gas piping, expansion tank, primary circulator and other accessories.

Controlling multiple GV90+ boilers

1. Multiple GV90+ boilers can be controlled using any boiler control/sequencing system that provides an isolated contact for call for heat (connected to the boiler's T-T terminals).

Figure 28 Side-to-side mounting of multiple GV90+ boilers,

showing RECOMMENDED clearances

Figure 29 Back-to-back installation of multiple GV90+ boilers,

showing RECOMMENDED clearances

Piping multiple GV90+ boilers

1. See suggested piping diagrams in this manual. Contact Weil-McLain for assistance for systems not covered.

2. Always pipe the boilers on a secondary loop in a primary/secondary circuit as shown in the examples in this manual.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Multiple boiler water piping

Easy-Fit® piping installation

1. Main header and Easy-Fit® Manifold pipe sizing.

a. New system — See page 15.

b. Replacing boilers in an existing system — Without reducing

size, connect system supply and return lines. Install tees or crosses for Easy-Fit ure 31. Size manifolds to handle total connected boiler output as shown.

2. Provide connections in main header for Easy-Fit® manifolds as close as possible to the midpoint of multiple boilers.

a. Use tees for four or less boilers, as in Figure 30.

b. Use either tees (Figure 30) or crosses (Figure 31) for ﬁve or

more boilers.

3. Manifold placement:

a. To alternate spacing for supply and return lines to boilers,

reverse the short-end and long-end of the manifolds as shown in Figure 30 and Figure 31.

b. Return manifold must be on the return side of the main and

supply manifold must be on the supply side of the main. Drawings in this manual show ﬂow in system main from right to left. For system ﬂowing left to right, reverse the locations of the manifolds accordingly.

4. Connect from Easy-Fit® manifold branches to boiler supply and return connections using copper or steel pipe, sized for the required ﬂow rate.

5. Provide a ﬂow/check valve in the supply piping of each boiler as shown in piping diagrams in this manual. Install an isolation valve on the supply and return of each boiler as shown. Some local codes may require the use of individual water level controls and limits on each boiler when isolation valves are installed.

6. Install main system air eliminator and primary circulator in supply piping as shown in piping diagrams. Place expansion tank on suction side of system circulator as shown.

7. Install system accessories as shown in drawings.

8. Piping recommendation drawings:

a. Figure 30 and Figure 31 show details of Easy-Fit b. Figure 32, page 25 is a schematic piping drawing showing the

locations of typical boiler piping and system piping, including limits and other devices often required by local codes.

c. Figure 33, page 26 and Figure 34, page 27 are three-dimensional

piping drawings of typical multiple boiler installation.

d. Figure 35, page 28 shows recommended piping when an isolat-

ing heat exchanger is needed.

9. If desired, other primary/secondary piping arrangements can be used.

manifolds as shown in Figure 30 or Fig-

manifolds.

Maximum connected load per manifold:

2-inch manifold — 450 MBH 3-inch manifold — 1400 MBH 4-inch manifold — 2900 MBH

Figure 30

Figure 31 Double-sided EZ-Fit Header connection

Single-sided EZ-Fit Header connection

When using isolation valves on each boiler, some codes

may require providing a low water control and additional limit for each boiler. Consult local codes to determine if omission of the individual boiler isolation valves may allow the use of a single water level control and additional limit for the entire multiple boiler system.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Multiple boiler water piping (continued)

Figure 32 Piping schematic — typical for multiple GV90+ boilers, using Weil-McLain Easy-Fit manifolds

Legend — Figure 32

1 Flow/check valve (each boiler)

2 Isolation valves (when used)

3 Cap

4 Easy-Fit® Manifold (supply) — layout and size per

page 24

5 Easy-Fit® Manifold (return) — layout and size per

page 24

6 Primary circulator

7 Expansion tank (diaphragm type)

8 System air eliminator

9 System automatic air vent

10 Pressure reducing valve

11 Check valve or backﬂow preventer, as required by applicable

codes

12 Isolation valve

13 Water ﬂow switch (when used)

14 Supply water temperature control (when used)

15 Low water cutoff (when used) (place above primary header)

16 Cold water ﬁll line — see Figure 15, page 14 for typical

components

18 System supply

19 System return

20 (Not shown) Boiler relief valve and discharge piping, installed

per GV90+ Boiler Manual

30 Long end of manifold

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Multiple boiler water piping (continued)

Figure 33 Piping layout — typical for multiple GV90+ boilers, using Weil-McLain Easy-Fit manifolds (2-boiler system)

Legend — Figure 33

1 Flow/check valve (each boiler) 2 Isolation valves (when used) 3 Caps 4 Easy-Fit® Manifold (supply) — layout and size per page 24 5 Easy-Fit® Manifold (return) — layout and size per page 24 6 Primary circulator 7 Expansion tank (diaphragm type) 8 System air eliminator 9 System automatic air vent 16 Cold water ﬁll line — see Figure 32, page 25 for typical com-

ponents

17 3-way diverting valve (operated by DHW aquastat — valve end

switch connects across boiler thermostat terminals) 18 System supply 19 System return 20 Boiler relief valve and discharge piping, installed per GV90+

Boiler Manual 21 Indirect-ﬁred storage water heaters — Example is shown connect-

ed to one boiler of the system. The indirect water heater could

also be connected with a secondary connection off the main

header, as in Figure 34, page 27.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Multiple boiler water piping (continued)

Figure 34 Piping layout — typical for multiple GV90+ boilers, with DHW storage heaters (4-boiler system)

1 Flow/check valve (each boiler)

2 Isolation valves (when used)

3 Caps

4 Easy-Fit® Manifold (supply) — layout and

size per page 24

5 Easy-Fit® Manifold (return) — layout and size

per page 24

6 Primary circulator

7 Expansion tank (diaphragm type)

8 System air eliminator

9 System automatic air vent

16 Cold water ﬁll line — see Figure 32, page 25

for typical components

18 System supply

19 System return

20 Boiler relief valve and discharge piping,

installed per GV90+ Boiler Manual

Suggested DHW boiler-side pipe sizing

(for max 0.04 feet head loss per foot of total equivalent length, TEL)

Flow rate Size Flow rate Size

1 – 4 gpm ¾” 22 – 45 gpm 2”

4 – 8 gpm 1” 45 – 75 gpm 2½”

8 – 14 gpm 1¼” 75 - 140 gpm 3”

14 – 22 gpm 1½” 140 – 290 gpm 4”

Legend — Figure 34

21 Indirect-ﬁred storage water heaters — Example is shown with a boiler

water circulator on each water heater. Alternatively, the water heaters could be connected with reverse return piping, using a common circulator.

22 Boiler water inlet

23 Boiler water outlet

24 DHW boiler-side circulators

25 DHW boiler-side return Easy-Fit® Manifold

26 DHW boiler-side supply Easy-Fit® Manifold

27 Flow/check valves (to prevent induced or gravity ﬂow in heating system or

DHW piping)

28 Check valve to prevent heat migration in heating system

29 Drain valves

30 Sensor for BCP (boiler control panel), when used

Note: See water heater manual for DHW piping — The DHW piping must also

be manifolded together since the boiler-side piping is manifolded. If DHW heaters supply separate DHW circuits, provide an individual circulator for each water heater, and control each circulator by its water heater’s aquastat.

This piping is sug-

ges t e d only. The layout above should be controlled with a boiler sequencing panel that provides DHW operation as well. Wire the heating system circulator to operate only on call for heat. Alternatively, use the boiler sequencing panel to provide domestic priority by disabling the heating system circulator any time there is a DHW call for heat. The boiler internal circulators operate on any call for heat, whether heating system or DHW. Offset the DHW boiler-side supply and return manifolds as shown so the total run of pipe and ﬁttings to each of the water heaters is approximately equal.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Multiple boiler water piping (continued)

Figure 35 Piping layout — typical for multiple GV90+ boilers, using isolation exchanger

Use isolation heat

exchanger for:

1. Large volume systems with high mineral content in water.

2. Systems exposed to untreated quantities of makeup water.

3. Old systems severely contaminated with scale and rust buildup inside piping and heat distribution units.

4. Process applications.

5. Commercial service water applications.

6. High water pressure applications, requiring pressure relief setting in heating system more than 50 PSIG (tall buildings). See notes below.

1 Flow/check valve (each boiler) 2 Isolation valves (when used) 3 Cap 4 Easy-Fit® Manifold (supply) —

layout and size per page 24

5 Easy-Fit® Manifold (return) — lay-

out and size per page 24

6a Heating system circulator (exchang-

er tube-side) 6b Heat exchanger shell-side circulator 7 Expansion tanks (diaphragm type) 8 System air eliminator

Legend — Figure 35

9 System automatic air vent

13 Cold water supply connections

16 Cold water ﬁll line — see Fig-

ure 32, page 25 for typical components

18 Heating system supply

19 Heating system return

20 Boiler relief valve and discharge

piping, installed per GV90+ Boiler Manual

30 Sensor for BCP (boiler control

panel), when used

Notes:

1. Contact heat exchanger manufacturer for heat exchanger shell-side and tube-side piping and circulator requirements. Tube-side ﬂow and temperatures must meet heating system requirements.

2. Contact heat exchanger manufacturer for sizing heat exchanger.

3. Heat exchanger shell-side circuit requires its own expansion tank as shown.

4. Heating system circuit requires its own expansion tank, as shown, plus its own relief valve set to protect heating system and heat exchanger piping and components.

5. When individual isolation valves are used, individual boiler and level controls may be required.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Venting & air — general

GV90+ boilers must be vented and

supplied with combustion and ventilation air using piping and methods

described in this manual

Inspect ﬁnished vent and air piping

Failure to provide a properly-installed

Failure to comply could result in severe

Every boiler must have its own vent. DO NOT common vent with any other

appliance.

thoroughly to ensure all are airtight and comply with the instructions provided and with all requirements of applicable codes.

vent and air system will cause severe personal injury or death.

If the vent/air piping conﬁgurations

covered in the GV90+ boiler manual cannot be applied for a particular installation, contact Weil-McLain for assistance. Other conﬁgurations may be available.

Where vent piping is routed through

an unheated space

1 inch of foil-faced ﬁberglass insulation on the length of the vent pipe in the unheated space.

Installations must comply with local

requirements and with the National Fuel Gas Code, ANSI Z223.1 for U.S. installations or CSA B149.1 or B149.2 for Canadian installations.

Use only the materials listed in this

manual for vent and air pipe and ﬁttings. See Figure 40, page 33.

If used, a masonry chimney can

ONLY be used as a PIPE CHASE for vent and air pipes

piping must be installed as instructed in this manual and all joints must be sealed. The chimney must be used only for GV90+ boilers. NO OTHER appliance or ﬁreplace can be connected to the chimney. The chimney must be straight, with no offsets, and the vent and air piping materials must comply with this instruction manual. The chimney must be ﬁtted with a sealed access opening, through which the interior of the chimney can be inspected. The chimney (and liner, if installed) must be inspected at least once annually to verify condition.

personal injury, death or substantial property damage.

— The vent and air

, apply minimum

When removing a boiler from an existing common vent system

The GV90+ boiler cannot be common vented with any other appliance.

the GV90+ boiler CANNOT use the existing common vent. The GV90+ boiler requires its own vent and air piping, as speciﬁed in this manual. This may cause a problem for the appliances that remain on the old common vent, because the vent may be too large. The following test, required by ANSI Z21.13, is intended to check for proper operation of the appliances remaining on the old common vent system.

When an existing boiler is replaced with a GV90+ boiler,

Vent system verication

At the time of removal of an existing boiler, the following steps shall be followed with each appliance remaining connected to the common venting system placed in operation, while the other appliances remaining connected to the common venting system are not in operation. Seal any unused openings in the common venting system.

Existing vent test procedure

(The following is intended to test whether the appliances remaining on an existing vent system will operate

satisfactorily.)

1. Visually inspect the venting system for proper size and horizontal pitch and determine there is no blockage or restriction, leakage, corrosion or other deﬁciencies which could cause an unsafe condition.

2. Test vent system — Insofar as is practical, close all building doors and windows and all doors between the space in which the appliances remaining connected to the common venting system are located and other spaces of the building. Turn on clothes dryers and any appliance not connected to the common venting system. Turn on any exhaust fans, such as range hoods and bathroom exhausts, so they will operate at maximum speed. Do not operate a summer exhaust fan. Close ﬁreplace dampers.

3. Place in operation the appliance being inspected. Follow the lighting instructions. Adjust thermostat so appliance will operate continuously.

4. Test for spillage at draft hood relief opening after 5 minutes of main burner operation. Use the ﬂame of a match or candle, or smoke from a cigarette, cigar, or pipe.

5. After it has been determined that each appliance remaining connected to the common venting system properly vents when tested as outlined herein, return doors, windows, exhaust fans, ﬁreplace dampers, and any other gas-burning appliance to their previous conditions of use.

Any improper operation of common venting system should be corrected so the installation conforms with the National Fuel Gas Code, ANSI Z223.1 — latest edition. Correct by re-sizing to approach the minimum size as determined using the appropriate tables in Part 11 of that code. Canadian installations must comply with B149.1 or B149.2 Installation Code.

Part number 550-142-054/1211

GV90+ gas-fired water boiler — Boiler Manual

Venting & air — general (continued)

Provide combustion air:

DIRECT VENT — The installation must provide com-

bustion air piping. In addition, ventilation openings may be required.

DIRECT EXHAUST — The installation must provide

combustion air openings to the boiler space.

ALL APPLICATIONS — The installation must provide

combustion air openings as needed for other appliances in the space.

Vent and air termination options

1. Vent and air piping must terminate out the sidewall or through the roof of the building, using only one of the methods described in this manual. See Figure 39, page 32 and Figure 40, page 33 for allowable conﬁgurations and piping materials.

DIRECT VENT installations

1. For direct venting, combustion air must be piped from outside to the boiler, following the instructions in this manual, and compliant with all applicable codes.

2. Ventilation openings are required for some spaces. See Figure 42, page 36.

3. If other appliances are located in the same space with the GV90+ boiler, provide openings shown in Figure 42, page 36.

If combustion and ventilation air openings are not provided

as directed above and the room does not have adequate ventilation, the higher temperature in the space may result in reduced component life.

Combustion air contamination:

Ensure that the combustion air will

not contain any of the contaminants in Figure 36

DO NOT place combustion air supply

openings or intake terminations near a swimming pool, for example.

Avoid areas subject to exhaust fumes

from laundry facilities. These areas will always contain contaminants.

Figure 36

Products to avoid

Spray cans containing chloro/ﬂuorocarbons Permanent wave solutions Chlorinated waxes/cleaners Chlorine-based swimming pool chemicals Calcium chloride used for thawing Sodium chloride used for water softening Refrigerant leaks Paint or varnish removers Hydrochloric acid/muriatic acid Cements and glues Antistatic fabric softeners used in clothes dryers Chlorine-type bleaches, detergents, and cleaning

solvents found in household laundry rooms

Corrosive contaminants and sources

DIRECT EXHAUST installations

1. Combustion and ventilation air must be provided in the boiler room on direct exhaust installations. Follow all instructions in this manual (see page 49 for air opening instructions) and all applicable codes to provide required air openings.

DO NOT sidewall vent DIRECT EXHAUST APPLICATIONS

at altitudes above 5,500 feet. Sidewall venting is only allowed for DIRECT VENT applications (ducted combustion air) at altitudes above 5,500 feet.

Adhesives used to fasten building products and other similar products

Excessive dust and dirt

Areas likely to have contaminants

Dry cleaning/laundry areas and establishments Swimming pools Metal fabrication plants Beauty shops Refrigeration repair shops Photo processing plants Auto body shops Plastic manufacturing plants Furniture reﬁnishing areas and establishments New building construction

Part number 550-142-054/1211

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Weil-McLain GV90+3, GV90+4, GV90+5, GV90+6 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual