How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Phil Your Own Question
Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
23932409
Type Your HVAC Question Here...
Phil is online now
A new question is answered every 9 seconds

I HAVE A LENNOX FURNACE WITH AN INTERMITTENT PILOT GAS

Customer Question

I HAVE A LENNOX FURNACE WITH AN INTERMITTENT PILOT GAS IGNITION CONTROL HONEYWELL S8600H (NOW OBSOLETE) A HONEYWELL NAT GAS VALVE VR8204A2076 (NOW OBSOLETE) AND A TJERLUND MODEL HSUL-J POWER VENTER (NOW OBSOLETE). I HAVE REPLACED THE 24 VOLT TRANSFORMER AND INSTALLED THE HONEYWELL S8610U INTERMITTENT PILOT GAS IGNITION CONTROL, I REPLACED THE IGNITION WIRE PILOT LIGHT BECAUSE I COULD NOT GET CONTINUITY WITH THE OLD WIRE AND THE PILOT LIGHT IGNITOR. THE PILOT VENTER DOES NOT COME ON WHEN THE THERMOSTAT CALLS FOR HEAT BUT THAT APPEARS TO BE BECAUSE I AM NOT GETTING 24 VOLTS ACROSS THE MV AND PV/MV TERMINALS ON THE GAS VALVE. AND IN READING THE TJERNLUND DATA IT WON’T PULL IN THE POWER RELAY TO THE POWER VENTER MOTOR UNLESS IT DOES. I DON’T GET A SPARK AT THE PILOT LIGHT IGNITOR IF THE POWER VENTER PROOF OF FAN SWITCH DOES NOT MAKE. I TESTED THE POWER VENTER MOTOR AND THE PROOF OF FAN SWITCH AND BOTH ARE OPERATING CORRECTLY.MY QUESTION IS WHY AM I NOT GETTING 24 VOLTS ACROSS THE MV PV/MV TERMINALS ON THE GAS VALVE? THE LENNOX MODEL NUMBER IS ***** THE S/N IS 4691G00031.
Submitted: 1 year ago.
Category: HVAC
Customer: replied 1 year ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Customer: replied 1 year ago.
I TRIED TO ENTER MY CELL NUMBER AND THE SYSTEM SAID MY EMAIL HAD ALREADY BEEN USED. I USED THIS SYSTEM A NUMBER OF YEARS AGO BUT DON'T REMEMBER SETTING UP AN ACCOUNT. MY CELL IS(###) ###-#### THERE IS NO DIRECTIONS FOR FINDING OUT MY OLD PASSWORD. MY E MAIL IS***@******.***.
Expert:  Tim H. replied 1 year ago.

Hi, I'm Tim and I'm an HVAC expert here to help answer your question(s). Please provide all the information I ask for since I'm not onsite. At the end of our dialog you will be asked to rate my service, but please wait until then and all your question(s) have been answered satisfactorily. If you are not satisfied, I'd appreciate it if you'd tell me why before leaving a negative rating and allow me to continue to work with you until we are able to both agree on an outcome to follow. Thanks for your business!

In order for the module to send voltage to the gas valve, you must first have 24 volts to 24 V (GND) and TH-W. Do you have 24 volts here o0n a call for heat?

Customer: replied 1 year ago.
Expert:  Tim H. replied 1 year ago.

If you do and control does not send 24 volts to pilot to light and then main gas, it would be a bad control.

Customer: replied 1 year ago.
NO IT IS THE SECOND CONTROL I HAVE INSTALLED. IT IS INTERLOCKING SOMEWHERE
Expert:  Tim H. replied 1 year ago.

The control is designed to send 24 volts to MV/PV and PV on gas valve and first light pilot. Then if the system has a flame sensor, it must sense pilot flame and then allow main gas to come on. I'm not sure what setup you have there as that's a very old furnace.

Customer: replied 1 year ago.
THIS IS NOT WORKING
Expert:  Tim H. replied 1 year ago.

Does your pilot have a separate flame sensor or not?

Customer: replied 1 year ago.
NO
Expert:  Tim H. replied 1 year ago.

Where do you have the sensor wire on the control? Is it connected or not:

Customer: replied 1 year ago.
I LEFT THE JUMPER ON PER INSTRUCTIONS
Expert:  Tim H. replied 1 year ago.

When you call for heat, does control spark and light pilot or not?

Customer: replied 1 year ago.
NO I DO NOT GET A SPARK AND PILOT DOES NOT LIGHT . BUT AS I LOOK AT THE POWER VENTER DOCUMENTATION UNLESS THE PROOF OF FAN SWITCH PULLS IN PILOTAND CLOSE THE SWITCH THE GAS VALVE WILL NOT OPEN TO THE PILOT
Expert:  Tim H. replied 1 year ago.

Is this a separate venter motor arrangement that you have? This is not standard to my knowledge.

Expert:  Tim H. replied 1 year ago.

Are you venting vertically through the side of the house? This would usually be where a Tjernlund would be used.

Customer: replied 1 year ago.
IT ISSEPERATE AND IT IS HORIZONTAL VENTING THE MODEL NUMBER IS *****
Expert:  Tim H. replied 1 year ago.

If you jump out the air proving switch does it then work?

Expert:  Tim H. replied 1 year ago.

Try that, and let me know. I have to step away for a few minutes, but will check back.

Customer: replied 1 year ago.
I AM NOT AT THE FURNANCE LOCATION NOW. I AM GOING TO THE FURNACE LOCATION TOMARROW TOMARROW. ARE YOU SAYING TO PUT 24 VOLTS ON THE VENTER POWER RELAY . MY UNDERSTANDING IS THE GAS VALVE OPENS FOR THE PILOT. MV PV/MV TERMINALS GET 24 VOLTS TO OPEN PILOT GAS. THAT 24 VOLTS PULLS IN THE 110 VOLTS TO THE POWER VENTER MOTOR . MOTOR ON FAN CAUSES PROOF OF FAN TO MAKE. PROOF OF FAN TELLS CONTROLER THROUGH THERMOSTAT TO OPEN GAS VALVE TO FURNACE BURNERS. EVERYTHING GET WARM. AM I RIGH HERE?
Expert:  Tim H. replied 1 year ago.

No, I'm just saying to jump past the air proving switch to see if the ignition process works.

Expert:  Tim H. replied 1 year ago.

If there is some special way this is wired, you'll have to let me know as I have access to standard Lennox furnace wiring diagrams, but not some optional equipment wiring.

Customer: replied 1 year ago.
I'LL TRY THAT TOMARROW. IS THERE A CASE NUMBER ***** THIS. AND CAN I ENTER A CASE NUMBERTO GET BACK TO YOU
Expert:  Tim H. replied 1 year ago.

Just bookmark the page and come back to it. Question will remain open.

Customer: replied 1 year ago.
OK I WILL BE THERE AFTER 12:00 CENTRAL TIME.
Expert:  Tim H. replied 1 year ago.

When you get a chance, please look at that Tjernlund manual you sent me a link to and go to the wiring diagram pages and tell me how yours is wired. It will probably correspond to one of those diagrams.

Customer: replied 1 year ago.
IS THERE A PRINT BUTTON HERE?
Expert:  Tim H. replied 1 year ago.

No, I don't believe so. Perhaps if you highlight everything and transfer it to another file, you can print.

Customer: replied 1 year ago.
HI TIM I'M SORRY BUT I CAN NOT GO TO THE FURNACED TODAY. BUT I AM NOT QUITING THIS SESSION. I HOPE TO GO TOMARROW BUT MY DAUGHTER IS UNCERTAIN
HARRY
Expert:  Tim H. replied 1 year ago.

OK, thanks for the update.

Expert:  Tim H. replied 1 year ago.

Let me know if you still wanted to work more on this question.