06-237172-002January 2017

™SERIES 35-608

INSTALLATION INSTRUCTIONS FOR FENWAL SERIES 35-608 DIRECT SPARK IGNITION CONTROLS

APPLICATIONSThe Fenwal 35-608 series Direct Spark Control (35-608) is a microprocessor based control suitable for many types of heat-ing applications including HVAC, commercial cooking, furnaces, boilers, and water heaters that require direct spark ignition, burner supervision through flame rectification, and safety shut-off. It is designed for use with Natural, LP, and mixed gases used in gas-fired appliances.

The microprocessor circuit design of the 35-608 provides pre-cise, repeatable timing and operating sequences. High energy spark output and excellent flame sense characteristics provide reliable burner operation. The on-board diagnostics with LED output make troubleshooting easy and ensure safe and efficient operation.

FEATURES• Safe start and full-time flame sensing• Automatic 1 hour reset after lockout option*• Wide variety of prepurge and interpurge timings**• Single or three trials for ignition• Diagnostic LED with Fenwal error codes• Green power LED• Remote or local flame sense options• RoHS compliant

AGENCY CERTIFICATIONS***

EN298 Classification AMC/RLXK

* Automatic reset after 1 hour is not allowed for CE approved models.** Prepurge time cannot exceed interpurge time on CE approved models.*** Certification varies by model.

CSA Design certified to ANSI Z21.20, CAN/CSA C22.2 No. 199-M99

SPECIFICATIONS

Input Power Control: 18-30 VAC 50/60 Hz, 8W (Class 2 Transformer)

Input Current Drain 300 mA @ 24 VAC with gas valve relay energized (Control only)

Main Gas Valve 5.0A max (continuous)

Operating Ambient Temperature -40°F to + 176°F(-40°C to +80°C)

Storage Temperature -40°F to + 185°F(-40°C to +85°C)

Flame Sensitivity 0.7 μA minimum

Flame Failure Response or Reignition Time

0.8 seconds minimum

Flame Detector Self-check Rate Once per second minimum

Flame Failure Lockout Time Varies by model, 300 seconds maximum

Types of Gas Natural, LP, or manufactured

Spark Rate Remote sense (50/60 Hz)Local sense (25/30 Hz)

Size (LxWxH) 5.20 x 3.95 x 2.50 inches(13.21 x 10.03 x 6.35 cm)

Moisture Resistance Conformal coated to operate non-condensing to 95% R.H.

Ingress Protection Not Rated, Protection provided by appliance in which it is installed

Tries for Ignition One or three try versions available

Trial for Ignition Periods 4, 7, 10, and 15 seconds available

Pre-purge Timings None, 15, or 30 seconds available

Inter-purge Timings None, 15, or 30 seconds available

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INSTALLATION GUIDELINES

MOUNTING AND WIRINGThe 35-608 is not position sensitive and can be mounted verti-cally or horizontally. The case may be mounted on any surface with #6 sheet metal screws.

WIRING DIAGRAMS

Figure 1. 35-6086 5/6 Pin

CAUTION

Label all wires prior to disconnection when ser-vicing or replacing controls. Wiring errors can cause improper and dangerous operation. A functional checkout of a replace-ment control should always be performed.

WARNING

The control must be mounted and located in a manner which protects components from expo-sure to water (dripping, condensate, spraying, rain). Any control that has been exposed to water must be replaced.

WARNING

All wiring must be done in accordance with both local and national electrical code. Wiring must be at least #18 AWG rated for 105°C or higher.

WARNING

The 35-608 uses voltages of shock hazard potential. Wiring and initial operation must be done by qualified service technician.

WARNING

Operation outside specifications could result in failure of the Fenwal product and other equip-ment with injury to people and property.

6-Pin Standard 35-608 Model (.156” Header)

Name Description Connection

MV Main Gas Valve Pin 1

TH Thermostat Pin 2

GND Ground Pin 3

GND Ground Pin 4

LAMP (NC) Normally Closed Pin 5

S1 Flame Sense Pin 6

6-Pin 35-6084 Model (.156” Header)

Name Description Connection

NC Alarm Lamp 24 Vac Pin 1

Reset Input (Special Order) Pin 2

TH Thermostat Pin 3

Valve GND Ground for Valve Pin 4

Valve Valve 24 Vac Pin 5

GND Control Ground Pin 6

S1 Remote Flame Sense Q.C. Terminal .250” Wide

8-Pin CE (EN298) Special Model (35-608300-015) (.156” Header)

Name Description Connection

ALARM Lockout Pin 1

24V 24 VAC Power Pin 2

RESET Manual Reset Pin 3

TH Thermostat Pin 4

GND Valve Return Pin 5

MV Main Gas Valve Pin 6

GND Ground Pin 7

GND Ground Pin 8

S1 Flame Sense Q.C. Terminal .250” Wide

Remote Sense

BURNER

1

2

5

6

3

4

FL AM E SENSOR

FC +

(2 CONTACTS)

FC -H.V.

LAMP (NC)

GNDGND

GAS VALVE

TH

MV

24 VACS1

Local Sense

BURNER

1

2

5

3

4

FC +

(2 CONTACTS)

FC -H.V.

LAMP (NC)

GNDGND

GAS VALVE

TH

MV

24 VAC

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Figure 2. 35-6084 6 Pin Local Sense Figure 3. 8 Pin Local Sense Wiring

FLAME SENSE CABLELocal Flame Sense cable is to include a voltage rating of 25 KV and an insulation rating of 200° C.

Remote Flame Sense cable is to include a voltage rating of 250 V and an insulation rating of 200° C.

Recommended length of Flame Sense cable is 3 ft (.91 m) or less. Consult factory for longer lengths.

Remote Sense

BURNER

1

4

5

2

3(2 CONTACTS)

H.V.

GNDGAS

VALVE

TH

VALVE

24 VAC

6

VALVEGND

RESET

NC

S1

Local Sense

BURNER

1

4

5

2

3(2 CONTACTS)

H.V.

GNDGAS

VALVE

TH

VALVE

24 VAC

6

VALVEGND

RESET

NC

S1

FL AM E SENSOR

Local Sense

BURNER

1

2

5

6

3

4

FC +

(2 CONTACTS)

FC -H.V.

GNDGND

GAS VALVE

TH

MV

24 VAC

7

8

GND

RESET

24VALARM

Remote Sense

BURNER

1

2

5

6

3

4

FC +

(2 CONTACTS)

FC -H.V.

GNDGND

GAS VALVE

TH

MV

24 VAC

7

8

GND

RESET

24VALARM

FL AM E SENSOR

S1

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SEQUENCE OF OPERATION / FLAME RECOVERY / SAFETY LOCKOUT

START UP - HEAT MODE When a call for heat is received from the thermostat supplying 24 volts to TH the following sequence occurs in the order listed:

1. The green power LED is illuminated.2. The control resets and then performs a self check routine,

flashing the red diagnostic LED once in the first two sec-onds.

3. The control begins a pre-purge delay. 4. Following the pre-purge period, the control energizes the

gas valve.5. The control enables the high voltage spark output for the

trial for ignition period. 6. When the control detects the presence of flame during the

trial for ignition, the control terminates the sparking pro-cess.

7. The thermostat and burner flame are constantly monitored to assure the system continues to operate properly.

8. When the thermostat is satisfied and the demand for heat ends, the main gas valve is de-energized immediately and the green LED turns off.

FAILURE TO LIGHT - LOCKOUTSINGLE TRIAL MODELShould the burner fail to light, or if the flame is not detected during the trial for ignition period, the control performs the fol-lowing actions:

1. The control enters ignition lockout.2. The main gas valve is de-energized immediately. 3. The diagnostic LED indicates the fault code for lockout.

MULTI TRIAL MODEL Should the burner fail to light, or if the flame is not detected during the first trial for ignition period, the control performs the following actions:

1. The main gas valve is de-energized. 2. The control then goes through an interpurge delay before

another ignition attempt. 3. The control attempts two additional ignition trials before

going into lockout and the main gas valve relay is de-ener-gized immediately.

4. The diagnostic LED indicates the fault code for lockout.

LOCKOUT RESETRecovery from lockout requires a manual reset by either recy-cling the thermostat or removing 24 volts for a period of 5 sec-onds. On models with automatic reset, if the thermostat is still calling for heat after one hour the control will automatically reset and attempt to ignite the burner.

CE versions have an option for non-volatile lockout. In this case, only the external RESET input must be used to recover from an ignition lockout.

FLAME FAILURE RESPONSE

RE-IGNITION MODE (STANDARD)If the established flame signal is lost while the burner is operat-ing, the control will respond within 0.8 seconds (max) by ener-gizing the HV spark for the programmed TFI period in an attempt to relight the burner. If the burner does not light within the TFI, the gas valve is de-energized immediately and on multi-try models a new TFI sequence begins.

If the burner does not relight, the control will lockout as previ-ously described in “Failure to Light - Lockout”. Multi-try models will make 2 more attempts to light the burner. If the flame is re-established, normal operation resumes.

RECYCLE MODE (OPTIONAL) With "recycle after loss of flame", upon loss of flame, the main gas valve is de-energized within 0.8 seconds (max). After the flame recycle delay, the control attempts to relight the burner. Multi-try models allow three tries for ignition including inter-purges. If the burner relights, normal operation resumes. If the burner does not relight, the control will go into lockout as described in “Failure to Light - Lockout”.

CHECKOUT

Test the gas control system after any service or component changes to the appliance using the following method:

1. Perform a visual check of all piping, burners, and venting. Check all wiring for integrity and proper electrical and ground connections. Verify the burner is properly grounded.

2. With the gas supply and thermostat off, turn on power to the appliance.

3. Turn the thermostat to a setting high enough to initiate a call for heat. Verify the ignition control proceeds through the operating sequence to a safety shutoff (lockout) condi-tion. (The burner will not light because the gas is shut off)

4. Turn off the thermostat.5. Turn on the gas supply, and purge the gas lines of air.

Check for gas leaks on all joints upstream of the gas valve with a soap solution.

6. Turn the thermostat to a setting high enough to initiate a call for heat. Verify the ignition control proceeds through the operating sequence to a normal run (burner lit) condi-tion. Confirm there are no gas leaks downstream of the gas valve using a soap solution.

7. Turn the thermostat setting down below the room tem-perature. Verify the burner flame goes out.

WARNING

Risk of Explosion or Fire Verify there are no gas leaks by using a rich soap and water solution on all joints and pipe connections. Never use a match or lighter to test for the presence of gas. Fail-ure to test properly before operation can lead to explosion or fire and may result in severe injury or death.

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TROUBLESHOOTING

Before troubleshooting the system, check the following items:

• Verify all mechanical and electrical connections are secure and tight.

• Verify all system wiring is correct.• Verify there is a proper system ground. The igniter, flame

sensor, and ignition module must share a common ground with the burner. Nuisance shutdowns are often caused by a poor or erratic ground.

• Perform the instructions in “Checkout” on page 4, as the first step in any troubleshooting.

• Verify that the system is powered and that the thermostat is calling for heat.

• Verify the green power LED is lit, indicating 24 VAC power to the control.

• If the control proceeds to an error code on the red diagnostic LED, troubleshoot per the Fault Conditions table below:

The LED will flash on for 1/4 second, then off for 1/4 second during a fault condition. The pause between fault codes is 3 seconds.

FLAME CURRENT MEASUREMENTFlame current is the current that passes through the flame from sensor to ground. To measure flame current, connect a True RMS or analog DC micro-ammeter to the FC+ and the FC- terminals. The reading should be 1.0 micro-amps DC or higher. If the meter reads negative or below “0” on the scale, the meter leads are reversed. Re-connect leads with proper polarity.

Alternately, a Digital Voltmeter may be used to measure the DC voltage between the FC+ and FC- terminals. Each micro-amp of flame current produces 1.0 VDC, so a reading of 2.6 VDC would equate to 2.6 micro-amps.

A good burner ground that matches the control ground is critical for reliable flame sensing.

INTERNAL CONTROL FAILUREIf the control detects an error in its software or hardware, all out-puts are turned off and the red LED displays a steady ON condi-tion. If this condition persists after an attempt to restart then the control must be replaced.

PROPER ELECTRODE LOCATIONProper location of the electrode assembly is important for optimal system performance. The electrode assembly should be located so that the tips are inside the flame envelope and about 1/2 inch (1.2 cm) above the base of the flame.

• Ceramic insulators should not be in or close to the flame.• Electrode assemblies should not be adjusted or disassem-

bled. Electrodes should have a gap spacing of 0.125± 0.031 inch (3.12± 0.81 mm), unless otherwise specified by the appliance manufacturer. If this spacing is not correct, the assembly must be replaced. Electrodes are NOT field-adjustable.

• Exceeding the temperature limits can cause nuisance lock-outs and premature electrode failure.

• Electrodes must be placed where they are not exposed to the appliance user in normal operation.

WARNING

Risk of Explosion or Fire The 35-608 control cannot be serviced by the user. If any control faults are detected, the 35-608 con-trol must be replaced by qualified service person-nel. Risk of explosion or fire can result if the control module has been opened or with any attempts to repair it, and the warranty is void.

Fault Conditions

LED Indication Fault Mode

Off Normal Operation

2 Flashes Flame without call for heat

3 Flashes Ignition Lockout

4 Flashes Manual Reset Error

Steady On Internal Control Failure

Troubleshooting Guide

Symptom Probable Cause

1. Control does not start, green LED is off.

A. Mis-wiredB. 24 VAC Transformer badC. Fuse/Circuit breaker bad (no power)

2. Thermostat on - no spark or valve

A. Mis-wiredB. Bad thermostat, no voltage at thermostat terminal TH C. Bad control, check red LED for steady on or flashing codes.

3. Valve on - no spark during TFI

A. Shorted electrodeB. Spark gap not correct. Set to .094-.156 inch.C. High voltage cable is faulty or has a poor connection.

4. Spark on - valve off

A. Gas Valve coil openB. Valve wire disconnectedC. Bad control, check voltage between gas valve terminal MV and GND.

5. Flame okay during TFI - no flame sense after TFI

A. Check electrode position and cleanlinessB. Check high voltage wireC. Poor ground at burnerD. Poor flame, check flame current

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DIMENSIONS

Figure 4. 6-Pin 35-6086 and 35-6084 Model Dimensions

Figure 5. 8-Pin 35-608 Model Dimensions

TH VAL

VE (G

ND)

GND

VAL

VE

NC

1.750 MAX.2.50 MAX.

3.940

.910

5.200

3.380

.283

3.375

RED LED

.187 ± .010 DIA.(4 MOUNTING HOLES)

GREEN LEDREMOTE FLAME SENSE TERMINAL

FC+FC-

5 or 6 PIN HEADER

1.750 MAX.2.15 MAX.

3.940

.910

5.200

3.380

.283

3.375

PIN 1

RED LED

8 PIN HEADER

.187 ± .010 DIA.(4 MOUNTING HOLES)

GREEN LED.250" Q.C. MALE

XX SEC

1.56” SPACING

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STANDARD PART NUMBER CONFIGURATION

35 – 6 0 8 X X X X X X –

TRIES FOR IGNITION & METHOD OF FLAME SENSE0 = Single Try - Local Sense1 = Single Try - Remote Sense2 = Single Try - Local Sense with 1 Hour Automatic Reset3 = Single Try - Remote Sense with 1 Hour Automatic Reset5 = Three Tries - Local Sense6 = Three Tries - Remote Sense7 = Three Tries - Local Sense with 1 Hour Automatic Reset8 = Three Tries - Remote Sense with 1 Hour Automatic Reset

PRE-PURGE0 = None1 = 15 Seconds2 = 30 Seconds

INTER-PURGE 0 = None1 = 15 Seconds2 = 30 Seconds

TRIAL FOR IGNITION1 = 4 Seconds3 = 7 Seconds5 = 10 Seconds7 = 15 Seconds

ENCLOSURE0 = Noryl Gray Enclosure1 = Integral Stand-Offs

PRODUCT DESIGNATION2 = CE (EN298) Standard Model3 = CE (EN298) Special OEM Configuration4= CE & CSA Hi Reliability5 = Standard QC Terminal6 = Multi-Pin Standard9 = Special OEM Configuration

Description

Fenwal Controls, Kidde-Fenwal Inc.400 Main Street

Ashland, MA 01721Tel: 800-FENWAL-1Fax: 508-881-7619

www.fenwalcontrols.com

This literature is provided for informational purposes only. KIDDE-FENWAL, INC. assumes no responsibility for the product’s suitability for a particular application. The product must be properly applied to work correctly. If you need more information on this product, or have a particular problem or question, contact KIDDE-FENWAL, INC.

06-237172-002 Rev BA ©2017 Kidde-Fenwal, Inc.

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