Part # 461006

MODEL PVFINDIRECT GAS FIRED FURNACES FOR ENERGY RECOVERY UNITS

Installation, Operation, and Maintenance Manual

®

RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE

WARNING!!!Improper installation, adjustment, alteration, service or maintenance can cause injury or death.Read the installation, operating and maintenance instructions thoroughly before installing orservicing this equipment.

ShippingCheck the unit for shipping damage. If any shipping damage is found, it should be reported to the last carrierand your local Greenheck representative.

Indirect Fired Gas Unit InstallationsUnits are listed for installation in the United States and Canada• Installation of gas fired duct furnaces must conform with local building codes. In the absence of local

codes, installation must conform to the National Fuel Gas code, ANSI Z223.1 or in Canada,CAN/CGA-B149 installation codes.

• All electrical wiring must be in accordance with the regulation of the National Electric Code,ANSI/NFPA No. 70.

• Unit is approved for installation downstream from refrigeration units. In these conditions, condensatecould form in the duct furnace and provision must be made to dispose of the condensate.

Model PVF, Indirect Gas Furnace, available in energy recovery models ERH and ERCH. For unit specificinformation, refer to IOM Part Number 459657 and 460945, respectively.

1. Do not install units in locations where flue productscan be drawn into adjacent building openings suchas windows, fresh air intakes, etc. Distance fromvent terminal to adjacent public walkways,adjacent buildings, operable windows, andbuilding openings shall conform with the localcodes. In the absence of local codes, installationshall conform with the National Fuel Gas Code,ANSI Z223.1, or the CAN/CGA B-149 InstallationCodes.

2. Building materials that will be affected by fluegases should be protected.

3. Avoid locating in an area where deep snow is likelyto accumulate. During the winter months, keepsnow clear on the access side of the unit toprevent any blockage of combustion air inlet orflue exhaust openings.

4. Maintain minimum horizontal clearance of 4 feetfrom electric meters, gas meters, regulators, andrelief equipment. In Canada, the minimumclearance is 6 feet.

5. Local codes may supercede any of the aboveprovisions.

6. Be sure that the minimum clearances tocombustible materials are maintained.

7. To prevent premature heat exchanger failure, donot locate units where chlorinated, halogenated, oracid vapors are present.

8. Units must not be installed in a potentiallyexplosive, flammable, or corrosive atmosphere.

For additional information on installation of the energyrecovery unit, refer to the following Installation,Operation, and Maintenance (IOM) manuals:

Model ERH: IOM Part #459657Model ERCH: IOM Part #460945

Unit Clearances to Combustible Materials

Outdoor Installations: Combustion blower dischargemust be located 42 in. from any combustiblematerials.

Indoor Installations: Clearances are determined bythe National Fuel Gas Code and/or other local codes.

2 ®

Installation - Location

Table of Contents

Installation . . . . . . . . . . . . . . . . . . . . . .2Location . . . . . . . . . . . . . . . . . . . . . . . . . .2Venting for Outdoor Units . . . . . . . . . . . .3Venting for Indoor Units . . . . . . . . . . . . .3Standard Indoor Venting . . . . . . . . . . . . .4Furnace Connection Locations . . . . . . . 5Concentric Venting . . . . . . . . . . . . . . . 5-7Two Pipe Venting . . . . . . . . . . . . . . . . .8-9Electrical Wiring . . . . . . . . . . . . . . . . . .10Gas Piping . . . . . . . . . . . . . . . . . . . . . . .11

Start Up . . . . . . . . . . . . . . . . . . . . . . .11Furnace Controls . . . . . . . . . . . . . . 12-13

Sequence of Operation . . . . . . . . . . .14Performance . . . . . . . . . . . . . . . . . . .14Troubleshooting . . . . . . . . . . . . . . . . .15Routine Maintenance . . . . . . . . . . . . .16

3 ®

1. Do not modify or obstruct the combustion air inlet cover or the combustion blower weatherhood.

2. During the winter months, periodically clear snow from access side of unit to prevent blockage of the inletand exhaust openings.

3. Do not add any vents other than those supplied by the manufacturer.

NOTE!Vent piping is supplied by others - not Greenheck.

Installation - Venting for Outdoor Units

Venting MethodsThere are three venting methods for indoor mountedunits. For each method, the units can be ventedhorizontally through an exterior wall or verticallythrough the roof. Specific venting instructions areprovided for each method and shown in the followingpages. Construct the vent system as shown in theseinstructions. Refer to your unit specific submittal todetermine the applicable venting option.

The three venting method options are:

1) Standard Indoor Venting- uses building air for combustion- vents exhaust to outdoors- one exterior roof or wall penetration

2) Separated Combustion Concentric Venting- uses outside air for combustion- vents exhaust to outdoors- one exterior roof or wall penetration

3) Separated Combustion 2-Pipe Venting- uses outside air for combustion- vents exhaust to outdoors- two exterior roof or wall penetrations

The following guidelines must be adhered to forall indoor units:

1. Venting installation must conform with localbuilding codes. In the absence of local codes,installation must conform with the National

Fuel Gas Code, ANSI Z223.1 or in Canada,CAN/CGA-B149 installation codes.

2. For Standard Indoor Venting, use exhaust pipeapproved for a category III appliance or singlewall, 26 gauge or heavier galvanized vent pipe.The piping is required to be gas tight by ANSI.

3. For Separated Combustion venting, sealedsingle-wall galvanized air pipe isrecommended.

4. The joints must be sealed with a metallic tapeor silastic suitable for temperatures up to350ºF.

5. A minimum of 12 inches of straight vent pipe isrecommended after the exhaust connectionand before any elbows.

6. Vertical combustion air pipes should be fittedwith a tee, drip leg, and clean-out cap toprevent any moisture in the combustion airpipe from entering the unit. The drip leg shouldbe cleaned out periodically during the heatingseason.

7. To reduce condensation, insulate any ventruns greater than 5 feet.

8. All vent pipe connections should be made withat least three corrosion resistant sheet metalscrews.

9. Refer to the National Fuel Gas Code foradditional piping guidelines.

Installation - Venting for Indoor Units

4 ®

Standard Indoor Venting - Horizontal

A = 12 in. minimum

A

Pitch vent pipedownward from

furnace 1⁄4inches per foot

Exhaust VentTerminal

EXHAUST

ExteriorWall

Air Inlet

Installing Exhaust Vent PipeInstall the vent pipe with a minimum downward slope (from the unit) of 1⁄4 inch per foot (horizontal venting only).Securely suspend the pipe from overhead structures at points no greater than 3 feet apart. Attach the ventterminal to the end of the exhaust pipe.

Standard Indoor Venting - Vertical

B

A = 12 inch minimumB = 12 inch minimum,

but should size according to expected snow depth.

EX

HA

US

T

Exhaust VentTerminal

Air Inlet

Roof Line

A

Installation - Standard Indoor Venting

Standard Indoor Venting uses one penetration through an exterior wall or roof for venting the flue exhaust. Thecombustion air is scavenged from the air inside the building (no piping required). When units are installed intightly sealed buildings, provisions should be made to supply an adequate amount of infiltration air from theoutside. The rule of thumb is that an opening of one square inch should be provided for every 1000 BTUs perhour of input rating.

Vent terminals must be used (one vent terminal included with each furnace). Construct the vent system as shownin the Horizontal and Vertical drawings below and reference the Vent Pipe Diameter table for the correct ventpipe diameters.

Vent Length LimitationsRefer to table at right for minimum and maximum ventlengths.The total equivalent vent length must includeelbows. The equivalent length of a 4 inch elbow is 6 feetand the equivalent length of a 6 inch elbow is 10 feet.

Min. Max.Vent Length (horizontal) 5 ft. 70 ft.Vent Length (vertical) 10 ft. 70 ft.

Vent Pipe DiameterSelect the vent pipe diameter from the table to theright. Use only the specified pipe size.

Furnace Exhaust Pipe Size (input MBH) Diameter

100-150 4 inches200-400 6 inches

Seal OpeningUsing an appropriate method, seal the wall/roof opening around the exhaust pipe.

5 ®

CVA-4 (4-inch ConcentricVenting Adapter)

CVA-6 (6-inch ConcentricVenting Adapter)

Exhaust ConnectionConcentric Side

Combustion Air ConnectionConcentric Side

Exhaust ConnectionNon-Concentric Side

Combustion Air Connection Non-Concentric Side

CVA

Installation - Concentric Venting (General)

Concentric venting allows the exhaust pipe and combustion air pipe to pass through a single hole in the roof orwall of the building. A concentric venting adapter (CVA) is required for concentric venting.

Depending upon whether the furnace was ordered for Horizontal or Vertical concentric venting, each indirect gasfurnace will ship with the following items:

Horizontal Venting: 1) Exhaust Pipe Vent Terminal, 2) Concentric Venting Adapter, and 3) Inlet GuardVertical Venting: 1) Exhaust Pipe Vent Terminal, 2) Concentric Venting Adapter, and 3) Inlet Terminal

The concentric venting adapter is designed for indoor installations and should never be installed on the exteriorof the building. The exhaust pipe must terminate with the vent terminal. For horizontal venting, the combustionair pipe must terminate with the inlet guard. For vertical venting, the combustion air pipe must terminate with theinlet terminal.

Installation - Furnace Connection Locations

A

D

E

F

B

C

3/

Exhaust Outlet

Combustion Air InletCombustionAir Inlet

ExhaustOutlet

ERH/ FurnaceA B C D E FERCH (MBH)

20 100-150 23.75 24.438 24.438 3.75 10.50 16.62545 100-150 23.75 24.50 24.50 6.00 12.75 18.87545 200-250 23.75 23.50 24.125 6.00 25.125 32.2555 150 26.63 27.25 27.25 6.00 12.75 18.87555 200-300 26.63 26.38 27.00 6.00 22.50 29.6390 300-400 37.63 37.38 38.00 6.00 25.00 32.125

3/4-in. GasConnection

6

EXHAUST

COMBUSTION AIR

Exterior Wall

MountingBracket

MountingBracket

A BExhaust Vent

Terminal

A = 2 inch minimumB = 12 inch minimum

Combustion AirInlet Guard

Pitch vent pipe downward fromfurnace 1⁄4 inches per foot

Installation - Concentric Venting

Refer to the diagram below for venting on horizontal concentric systems. Maintain at least 12 inches from thecombustion air inlet guard to the exhaust vent terminal (Dim. B). To prevent water from running into thecombustion air pipe and to allow for easy installation of the combustion air guard, the combustion air pipe mustterminate at least 2 inches from the exterior surface of the outside wall (Dim. A).

Horizontal Venting

Refer to the diagram below for venting on vertical concentric systems. Maintain at least 12 inches between thetop of the combustion air inlet terminal and the bottom of the exhaust vent terminal (Dim. B). The bottom of thecombustion air inlet terminal must terminate above the snow line, or at least 12 inches above the roof, which everis greater (Dim. A). A tee with cleanout must be provided on the combustion air and exhaust pipe to preventdebris from entering the heat exchanger.

Vertical Venting

Exhaust Vent Terminal

Combustion AirInlet Terminal

A

C

C

BRoofline

EX

HA

US

T

CO

MB

US

TIO

N A

IR

Tee with drip leg andcleanout cap

A = 12 inch minimum, but should size according to expected snow depth.

B = 12 inch minimumC = 12 inch minimum

MountingBracket

MountingBracket

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7 ®

Step 1 Determine Venting LocationDetermine the location of the concentric ventingadapter (CVA) based on any clearances that must bemaintained (follow all codes referenced in theseinstructions).

Step 2 Attach Mounting BracketsAttach field supplied, corrosion resistant, mountingbrackets to the CVA using corrosion resistant sheetmetal screws.

Step 3 Install Exhaust PipeSlide the exhaust pipe through the CVA. Provideenough exhaust piping to pass through the wall (orfloor) and provide the minimum clearance of 12 inchesbetween the exhaust pipe termination and thecombustion air intake. With all required clearancessatisfied, attach the exhaust pipe to the CVA.

Step 4 Install Combustion Air PipeAttach a field supplied combustion air pipe to theconcentric side of the CVA.

For horizontal venting, provide enough combustion airpiping to pass through the wall and provide theminimum clearance of 2 inches between thecombustion air intake and the exterior surface of theoutside wall.

For vertical venting, provide enough combustion airpiping to pass through the roof and provide theminimum clearance of 12 inches between thecombustion air intake and the exterior surface of theroof. This clearance may need to be increased to allowfor snow accumulation.

Be sure to maintain the minimum clearance of 12inches between the exhaust pipe termination and thecombustion air intake.

Step 5 Install CVA AssemblyPlace the CVA assembly through the wall/roof andverify that all minimum clearance requirements asspecified in these instructions are met. Secure theCVA assembly to the wall/ceiling with mountingbrackets and corrosion resistant sheet metal screws.

Step 6 Attach CVA Assembly to UnitAttach the exhaust pipe to the unit’s combustionexhaust. Using an additional combustion air pipe,connect the unit’s combustion air supply intake to thecombustion air connection on the CVA. For verticalventing, include the required tees with drip legs andclean outs.

Step 7 Install Combustion Air InletGuard/Terminal and Exhaust VentTerminalSlide the combustion air inlet guard (for horizontalventing) or the inlet terminal (for vertical venting) overthe exhaust pipe and fasten it to the combustion airpipe. Attach the exhaust vent terminal to the dischargeend of the exhaust piping.

Step 8 Seal OpeningSeal the opening between the wall/floor and the airintake pipe using an appropriate method.

Furnace Size Exhaust Combustion(MBH) (Inches) (Inches)

100 - 150 4 6200 - 400 6 8

Combustion AirConnection

ExhaustConnection

IGFurnaceControlCenterAccess

Vent LengthRefer to table at right for minimum and maximum ventlengths. The total equivalent vent length must includeelbows. The equivalent length of a 4 inch elbow is 6 feetand the equivalent length of a 6 inch elbow is 10 feet.

Min. Max.Vent Length (horiz.) 5 ft. 70 ft.Vent Length (vertical) 10 ft. 70 ft.

Installation - Concentric VentingConcentric Vent Connection DiameterVent terminals must be used (one vent terminalincluded with each furnace). Construct the ventsystem as shown in the Horizontal and Verticaldrawings on previous page and reference the table atthe right for the correct vent connection diameters.

C

D

D

B

A

A = 12 inch minimum, but should size according to expected snow depth.

B = 12 inch minimumC = 12 inch minimumD = 12 inch minimum

EX

HA

US

T

CO

MB

US

TIO

N A

IR

Tee with drip leg andclean-out cap.

Combustion AirInlet Terminal

Exhaust VentTerminal

8

Exterior Wall

B

A

EXHAUST

COMBUSTION AIR

Pitch vent pipe downward fromfurnace 1⁄4 inches per foot

C

Field SuppliedSupport Brackets

A = 12 inch minimumB = 12 inch minimumC = 12 inch minimum

Exhaust VentTerminal

Combustion AirInlet Terminal

Installation - Two Pipe Venting

Refer to the diagram below for venting on horizontal two pipe systems. Maintain at least 12 inches of clearancebetween the exhaust pipe termination and the exterior surface of the outside wall (Dim. A). The combustion airpipe must be a minimum of 12 inches below the exhaust pipe (Dim. C) and 12 inches from the exhaust pipe ventterminal (Dim. B). A minimum of 1 inch and a maximum of 48 inches of building wall thickness is required forseparated combustion vent pipe.

Horizontal Venting

Refer to the diagram below for venting on vertical two pipe systems. The combustion air pipe must terminate atleast 12 inches above the roof. This clearance may need to be increased to accommodate for snowaccumulation (Dim. A). The exhaust must terminate at least 12 inches above (Dim. B) and 12 inches horizontally(Dim. C) from the combustion air inlet.

Vertical Venting

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9 ®

Furnace Size Exhaust Combustion(MBH) (Inches) Air (Inches)

100 - 150 4 4200 - 400 6 6

Step 2 Install Exhaust PipeRun an exhaust pipe from the unit’s combustionexhaust through the exterior wall/roof to the outdoors.

For horizontal venting, the exhaust pipe mustterminate at least 12 inches from the exterior surfaceof the outside wall and at least 12 inches above thecombustion air pipe. Attach exhaust vent terminal tothe end of the exhaust pipe. Using field suppliedmounting brackets, support the exhaust pipe asneeded.

For vertical venting, maintain at least 12 inchesbetween the bottom of the exhaust vent terminal andthe top of the combustion air inlet terminal. Maintainat least 12 inches horizontally between the exhaustvent and the combustion air inlet. Attach exhaust ventterminal to the end of the exhaust pipe.

Step 3 Seal OpeningsUsing an appropriate method, seal the wall/roofopenings around the piping.

Step 1 Install Combustion Air PipeRun a combustion air pipe from the unit’s combustionair intake through the exterior wall/roof to theoutdoors.

For horizontal venting, the combustion air pipe mustterminate at least 12 inches from the exhaust pipevent terminal. Attach the combustion air inlet terminalto the end of the combustion air pipe. Using fieldsupplied mounting brackets, support the combustionair pipe as needed.

For vertical venting, the combustion air pipe mustterminate at least 12 inches above the roof. Thisclearance may need to be increased to accommodatesnow accumulation.

Installation - Two Pipe Venting

Vent LengthRefer to table at right for minimum and maximum ventlengths. The total equivalent vent length must includeelbows. The equivalent length of a 4 inch elbow is 6 feetand the equivalent length of a 6 inch elbow is 10 feet.

Min. Max.Vent Length (horiz.) 5 ft. 50 ft.Vent Length (vertical) 10 ft. 70 ft.

Two Pipe Vent Connection DiameterVent terminals must be used (two vent terminalsincluded with each furnace). Construct the ventsystem as shown in the Horizontal and Verticaldrawings on previous page and reference the table atthe right for the correct vent connection diameters.

Combustion AirConnection

ExhaustConnection

IGFurnaceControlCenterAccess

10

1. Installation of wiring must conform with local building codes. In the absence of local codes, installation mustconform to the National Electric Code ANSI/NFPA 70-Latest Edition. Unit must be electrically grounded inconformance with this code. In Canada, wiring must comply with CSA C22.1, Canadian Electrical Code.

2. All furnaces are provided with a wiring diagram located on the inside of the access panel. Refer to this wiringdiagram for all wiring connections.

3. The combustion blower motor will not run unless the furnace is turned on and the gas controls are calling forheat.

WARNING!!!• Disconnect power supply before making wiring connections to prevent electrical shock and equipment

damage.

• All appliances must be wired strictly in accordance with wiring diagram furnished with the unit. Any wiringdifferent from the diagram could result in a hazard to persons and property.

• Any original factory wiring that requires replacement must be replaced with wiring material having atemperature rating of at least 105°C.

1. Two-stage temperature controls - Controls thefurnace stages based on the unit dischargetemperature.

2. Combustion blower - Exhausts the products ofcombustion from the furnace tubes.

3. Ignition controller - Continually monitors,analyzes, and controls the proper operation ofthe gas burner.

4. Manifold pressure test port (1⁄4-in. pipe thread)- Used for checking the manifold gas pressure.

5. Time delay relay - Allows burner to stay at highfire for 10 seconds upon being lit.

6. Air pressure switch - Tests to ensure thecombustion blower is operating.

7. Two-stage gas valve - Contains main pressureregulator, safety shut-off valves, and manualshut off knob. It controls the furnace to 50% or100% fire.

8. Ignitor - Provides spark for burner ignition.

9. Flame sensor - Ensures that each burner hasignited.

Control Center Layout

1

23

4

5 6

7

8

9

Furnace Control Center

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Installation - Electrical Wiring

11 ®

1. Furnaces (input 100 to 400 MBH) have a single 3⁄4-inch, female pipe thread connection.

2. When connecting the gas supply, the length of therun must be considered in determining the pipesize to avoid excessive pressure drop. Refer to aGas Engineer’s Handbook for gas pipe capacities.

3. A 6-inch drip leg should be installed in the pipe runto the unit.

4. Install an easily accessible ground joint union and amanual shut off valve (these are required by somelocal codes) for emergency shut off and easyservicing of the controls.

5. A 1⁄8 inch NPT plugged tap shall be installed immediately ahead of the gas supply connection tothe furnace.

6. After gas piping is completed, carefully check all piping connections for gas leaks. Use soap solutionor equivalent for testing. DO NOT use a flame orother source of ignition to check for gas leaks.

7. When leak testing pressures above 14 in. wg (1⁄2 psi),close the field installed shutoff valve, disconnect

the furnace and its gas train from the gas supplyline, and plug the supply line before testing.

8. When leak testing at pressures equal to or less than14 in. wg (1⁄2 psi) close the field-installed shutoffvalve to isolate the unit from the gas supply linebefore testing.

* Falling below minimum gas pressure requirementswill reduce the MBH output. In turn, the unit will notbe able to fully condition the space on peak heatingdays. If gas pressure is simply too low forrequirements, we recommend the local gas companybe contacted to determine if a booster pump wouldbe feasible.

FromGas

Gas Cock

1/8 in. Plugged

6 in. Trap

Ground Joint Union

To Controls

Recommended Piping to Controls

Gas Supply Pressure RequirementsNatural: 6* to 14 in. wg

LP: 11* to 14 in. wg

Installation - Gas Piping

1. Turn off power to the unit at the disconnect switch.Close all manual gas valves.

2. Check that all gas and electrical connections areweatherized.

3. Make sure that the combustion air inlet and thecombustion blower discharge are free from obstructions.

4. Inspect the unit to make sure that no damage hasoccurred during installation.

5. With the furnace control center access panelremoved, connect a “U” tube manometer to themanifold pressure test port (refer to the ControlCenter Layout under Installation). This will be usedfor checking the manifold gas pressure.

6. Set the thermostat or discharge temperaturecontrols to lowest setting.

7. Open all manual gas valves including thecombination gas valve and turn power on.

8. Call for heat with the thermostat or dischargetemperature controls and allow the burner to light.Greenheck duct furnaces are equipped with anautomatic spark ignition system whichautomatically lights the burner. DO NOT attempt tolight the burners manually.

9. After the burner is lit, check to make sure that thesupply blower is operating.

10.Verify that the gas controls sequence properly (seeSequence of Operation).

11.Check the manifold gas pressure (see BurnerAdjustments on following pages).

Start-Up Procedure

Start-Up

12 ®

Setting Manifold Pressure for Two Stage Gas Control1. Set the unit to high fire by setting the discharge

temperature control or thermostat to itsmaximum setting. If the ambient temperature iswarm, the unit may not stay at high fire.

2. Measure the burner manifold pressure at themanifold pressure test port (see ControlCenter Layout on page 3) using a “U” tubemanometer. The pressure on high fire shouldbe 3.5 in. wg for natural gas and 10 in. wg forLP gas. To change the pressure, adjust theregulator adjustment screw on the combinationgas valve. Clockwise rotation will decrease thegas pressure and counter clockwise rotationwill increase the gas pressure.

3. Set the unit to low fire by removing the wirefrom the high fire terminal on the combinationgas valve. Clockwise rotation will decrease thegas pressure and counter clockwise rotationwill increase the gas pressure.

4. The manifold pressure on low fire for natural gas should be 0.88in. wg and 2.5 in. wg for LP gas. To change the pressure, usethe low fire adjustment screw on the combination gas valve.

Staged Burner Adjustments

For Energy Recovery Units without Temperature Control PackageThe furnace stage controls are located in the furnace control center. One control isprovided for each stage of heating. The discharge temperature setting is locatedon the control furthest to the left. The offset and differential settings for each stageare preset at the factory; however, field-adjustments may be made to get the bestcontrol for your application. See the literature provided with the controls for furtherinformation.

For Energy Recovery Units with Temperature Control PackageIf two-stage control is ordered with a Temperature Control Package, the controllerin the unit’s main control center will control the stages of heating. The temperatureset point may be adjusted on the controller (See Temperature Controller IOM).

Staged Temperature Controls

High Fire AdjustmentLow Fire Adjustment

Solenoid

High FireTerminal

Figure 3: Staged Controls

Figure 4: Combination Gas Valve

Turndown ModulationTwo Stage 2 : 1 50% , 100%Electronic Modulation 2 : 1 50% - 100%

Start-Up - Furnace Controls

13 ®

High Fire Operation1. Place a jumper between terminals 7 and 8 on the

Maxitrol amplifier.2. Measure the burner manifold pressure at each

furnace at the pressure test port (see ControlCenter Layout under Installation) using a highquality manometer that can measure low gaspressures. The pressure at high fire should be 3.5in. wg for natural gas and 10.0 in. wg for LP Gas.To change the pressure, adjust the high fire screw(under cap screw) on the combination gas valve.Clockwise rotation will decrease the gas pressureand counter clockwise rotation will increase gaspressure.

Low Fire Operation3. Remove the wire from terminal 3 on the amplifier

and isolate it from touching anything. Set thedischarge temperature selector to the highest

setting. If there is a room override thermostat, turnthe dial to the highest setting.

4. Measure the manifold pressure on low fire, itshould be 0.88 in. wg for natural gas and 2.5 in. wgfor LP gas.

5. To adjust the low fire, remove the bypass cap (A)and turn screw (B) as shown in diagram. Adjust thescrew indicated in Figure 5 on the modulatingvalve. Clockwise rotation will decrease gaspressure and counterclockwise rotation willincrease gas pressure.

6. Reconnect wire to terminal 3.7. Remove jumper and place all wires back to where

they were and plug the manifold pressure port.

Electronic ModulationTemperature ControlsFor Energy Recovery Units withoutTemperature Control PackageA Discharge Temperature Dial isused for temperature control forelectronic modulation. Thetemperature dial will be located inthe furnace control center.

For Energy Recovery Units withTemperature Control PackageThe Temperature Controller in theunit’s main control center willprovide the electronic modulationcontrol.

High and Low Fire Settings forElectronic Modulation

Electronic Modulation Valves

Check the high and low gaspressures on initial start up per theinstructions below. These settingsare pre-set at the factory, but shouldbe adjusted in the field if necessary.Set the high fire first and the low firesecond. The low fire must always bechecked if the high fire is changed.

Modulating ValveLow fire adjustment

Combination Gas ValveHigh fire adjustment

B

Manifold Pressure (in. wc)Natural Gas LPLow High Low High

2 : 1 Electric Modulation 0.88 3.5 2.5 10

Start-Up - Furnace Controls

Performance Data

Ratings shown are for elevations up to 2000 ft. For higher elevations, the input should be reduced by 4% per 1000 ft. ofelevation above sea level. In Canada, from 2000 to 4500 ft in elevation, the unit must be derated to 90% of the input listedabove. The unit shall also be used in accordance with standard CGA 2.17.

Power-up/StandbyAfter power is supplied to the unit:

1. The ignition control will reset and perform a self-check routine.

2. The diagnostic LED will flash for up to fourseconds.

3. The ignition control will begin scanning thethermostats.

Heat ModeWhen the thermostat or discharge temperaturecontrols call for heat:

1. The ignition control will check that the pressureswitch for the combustion blower is open.

2. The combustion blower will be energized and the15-second pre-purge begins.

3. The gas valve is energized and the ignitor will sparkfor up to 10 seconds.

Natural Gas - If a flame is not sensed during thetrial for ignition, two additional trials will beattempted before going into lockout for one hour.

LP Gas - If a flame is not sensed during the trial forignition, the control will go into lockout for onehour.

4. When a flame is sensed, sparking stopsimmediately. The gas valve and combustion blowerremain energized.

5a. Two-stage control: The burner will light at 100%fire and remain there for 10 seconds. Thethermostat will then operate the burners at high orlow fire, depending on the demand for heat.

5b. Electronic Modulation - The burner will light at100% fire and remain there for 10 seconds. Themain burner gas valve will then modulate from100% down to 50% as needed. If the burnerremains on low fire for an extended period of time,the burner will shut off and re-light as necessary.

6. The ignition control constantly monitors thethermostat, pressure switch, and burner flame toassure proper operation.

7. When the thermostat or discharge temperaturecontrols are satisfied, the main valve is de-energized and the combustion blower shuts offfollowing a 30-second post-purge period.

Recovery from LockoutThe ignition control will automatically reset after 1 hourif the thermostat is still calling for heat. Prior to 1 hour,a manual reset (cycle power to unit) is required. Thethermostat may be reset or the power interrupted for aperiod of 5 seconds. See page 7 for Ignition ControlDiagnostics.

Sequence of Operation

Air Temperature Rise Through Unit (°F)Model Input Output 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

Number (MBH) (MBH) CFM

PVF 100 100 80 3704 2963 2469 2116 1852 1646 1481 1347 1235 1140 1058 988 926 871 823 780 741

PVF 150 150 120 5556 4444 3704 3175 2778 2469 2222 2020 1852 1709 1587 1481 1389 1307 1235 1170 1111

PVF 200 200 160 7407 5926 4938 4233 3704 3292 2963 2694 2469 2279 2116 1975 1852 1743 1646 1559 1481

PVF 250 250 200 9259 7407 6173 5291 4630 4115 3704 3367 3086 2849 2646 2469 2315 2179 2058 1949 1852

PVF 300 300 240 11111 8889 7407 6349 5556 4938 4444 4040 3704 3419 3175 2963 2778 2614 2469 2339 2222

PVF 350 350 280 12963 10370 8642 7407 6481 5761 5185 4714 4321 3989 3704 3457 3241 3050 2881 2729 2593

PVF 400 400 320 14815 11852 9877 8466 7407 6584 5926 5387 4938 4558 4233 3951 3704 3486 3292 3119 2963

14 ®

Sequence of Operation

Performance

Ignition Control Diagnostic LEDDuring normal operation, the LED is shut off. The LEDwill be on or flashing during a fault condition. If a faultcondition is occurring, turn the unit off and on again. Ifthe LED is still flashing, refer to the followingtroubleshooting section.

LED Indication Error ModeSteady on Internal control failure1 flash Air flow fault2 flashes Flame with no call for heat3 flashes Ignition lockout

Possible Cause SolutionManual gas valve not open Open manual valve

Air in the gas line Bleed gas line

Supply gas pressure too high or too low Check that supply pressure is between 6 in. wg and 14 in. wg for natural gas and 11 in. wg and 14 in. wg for LP.

Loose wire connections Check for tight wire connections.

No spark:

a. Transformer failure a. Check primary and secondary voltages of transformer. Replace if necessary.

b. Spark electrode b. Ensure spark gap is 1⁄8 in. and ceramic insulator is not cracked. Replace if necessary. Electrode is NOT field-adjustable.

c. Spark cable shorted to ground c. Replace spark cable

d. Ignition controller not grounded d. Check that the ignition controller is grounded to the furnace control center.

High limit control tripped Check unit airflow and manifold pressure.

Faulty combination gas valve If 24 volts is measured between terminals MV and common, but valve remains closed, replace valve.

Faulty ignition control Check diagnostic LED for steady on and for voltage between V1 and V2. If no voltage is present, replace ignition control.

Airflow Fault (1 Flash)An airflow fault may occur for the following reasons:

• An airflow switch continually monitors the combustion airflow during an ignition sequence. During theinitial call for heat, if the pressure switch contacts are in the closed position for 30 seconds without anoutput to the combustion blower, an airflow fault will be declared. The control will remain in this mode withthe combustion blower off.

• After the combustion blower output (L1 and IND) is energized and the airflow switch remains open formore than 30 seconds, an airflow fault will be declared. The control will stay in this mode with thecombustion blower on, waiting for the airflow switch to close.

• If the airflow signal is lost while the burner is firing, the control will immediately de-energize the gas valveand the combustion blower will remain on. If the call for heat remains, the control will wait for properairflow to return. If proper airflow is not detected after 30 seconds, an airflow fault will be declared. Ifproper airflow is detected at any time, a normal ignition sequence will begin.

Once proper airflow is detected, the normal Sequence Of Operation for ignition will follow (see page 4).

Flame Fault (2 Flashes)If the main valve fails to close completely and maintains a flame, the full-time flame sense circuit will detect itand energize the combustion blower. Should the main valve later close completely and remove the flame signal,the combustion blower will be de-energized.

Ignition Lockout (3 Flashes)

15 ®

Troubleshooting

Combustion Blower MotorMotor maintenance is generally limited to cleaning.Cleaning should be limited to exterior surfaces only.Removing dust and grease build-up on the motorhousing assures proper motor cooling. Use cautionand do not allow water or solvents to enter the motoror bearings. Under no circumstances should motors orbearings be sprayed with steam, water or solvents.The motor bearings are pre-lubricated and sealed,requiring no further lubrication.

Burners and OrificesBefore each heating season, examine the burners andgas orifices to make sure they are clear of any debrissuch as spider webs, etc. Clean burner as follows:

• Turn off both electrical and gas supplies to theunit.

• Disconnect union between manifold and gasvalve.

• Remove manifold and burner assembly.• Inspect and clean orifices and burners as

necessary. Avoid using any hard or sharpinstruments which could cause damage to theorifices or burners.

- Remove any soot deposits from the burnerwith a wire brush.

- Clean the ports with an aerosol degreaseror compressed air.

- Wipe the inside of the burner clean.Cleaning the burner with a degreaser willslow the future buildup of dirt.

• Before reinstalling the burner assembly, lookdown the heat exchanger tubes to make surethey are clear of any debris.

• Reinstall manifold and burner assembly,reconnect wire leads, and gas supply piping.

• Turn on the electrical power and gas supply.• Follow the start-up procedure to light the

burners and verify proper operation.

Heat ExchangerThe heat exchanger should be checked annually forcracks and discoloration of the tubes. If a crack isdetected, the heat exchanger should be replacedbefore the unit is put back into operation. If the tubesare dark gray, airflow across the heat exchangershould be checked to make sure the blower isoperating properly.

Flue Collector BoxThe flue passageway and flue collector box should beinspected prior to each heating season and cleared ofany debris.

Electrical WiringThe electrical wiring should be checked annually forloose connections or wiring deterioration.

Replacement PartsWhen ordering replacement parts, include thecomplete unit model number and serial number listedon the unit rating plate.

CAUTION!!!Turn off all gas and electrical power to the unit before performing any maintenance orservice operations to this unit.

Copyright © 2005 Greenheck Fan Corp.ERH/ERCH - PVF IOM FS

Rev. 3 January 2005

WarrantyGreenheck warrants this equipment to be free from defects in material and workmanship for a period of oneyear from the purchase date. Any units or parts which prove to be defective during the warranty period willbe repaired or replaced at our option.

The motor is warranted by the motor manufacturer for a period of one year. Should the motor provedefective during this period, it should be returned to an authorized motor service station.

Greenheck will not be responsible for any installation or removal costs.

Routine Maintenance