Jandy JXi 200n Blower not turning on - Running out of troubleshooting steps

[NickPSI]

Hello everyone, first off this forum is a massive resource of information. I was hoping one of the vets here can help me down the right path.

Here is where I am at. Advanced in technical-inclination (at least I think so)

Natural Gas Jandy JXi 200n, about 6 years old now. I bought the house last year it performed flawlessly all year. This year would not turn on, gave me check ignition steps fault. As a newb with pool equipment I started with the ignitor, found the porcelain was cracked and it tested as open circuit. Replaced that, and still nothing (I handled it very carefully and did not touch the element with my fingers).

Noticed the power distribution board has burn marks on the "chip" in the middle and the socket. I made a wiring diagram for 220v and just soldered jumpers on the board in the same fashion as the chip (used 12awg, which is even bigger than that is in the unit), still nothing.

Started reading just about everything here and continued on....

Now I run through the entirety of the troubleshooting steps in the Jandy graphic, all sensors test 24v to ground, 24v is being supplied to the W terminal on the Fenwal. I check F2 and theres nothing. F1 has 110v, F2 nothing. Fenwal is displaying airflow fault. The blower has not kicked on one time during this entire process.

I jump f1 and f2 to test the blower, it powers up great and runs fine. I check for 24v on both sides of the pressure switch and the normally open contacts are closing fine. When I run the unit with the blower jumped I never get any heat out of the exhaust.

I feel the unit is not igniting. Both of my gas shutoffs are open.

What is the next troubleshooting step? Could my ignitor still be bad (yes) and I'm not getting ignition? How can I verify the gas valve is opening?

 

[PoolGate]

Does it try to light? Do you smell gas?

 

[NickPSI]

I do not smell gas. Nothing at all happens.

I am finding now there is never a 24 volt signal to the gas valve coil. I killed all power and had my leads not only on the end of the conductors at the valve but I also tried directly on the fenwal MV1/VAL terminal and its always 0v AC. I also find it is giving the ignitor 90v instead of 120. The ignitor has 125ohms of resistance so its still alive

Does this mean Fenwal is dead, or is there an operation besides 24v to the W terminal to call for heat that I am not seeing to trigger voltage to the gas valve?

 

[NickPSI]

It looks like order of operations is:

Receive 24v to W "Call for heat"
Fenwal checks air pressure contacts. If open, energizes blower.
Pressure contacts close from blower pressure, which send the signal to open gas valve (Unit wont send the gas unless the blower is running)
Fenwal sees gas valve open energizes ignitor until flame is detected

I feel my fenwal blower relay is bad and not starting the blower to close the pressure switch, so it isnt sending the signal to open the gas valve. The ignitor circuit at 90v is odd however. Also this may not be true, as when i had the blower jumped out to power it I still didnt get heat from the exhaust of the unit.

 

[NickPSI]

I ordered a fenwal, I'll update if it fixes everything or not.

 

[1poolman1]

It looks like order of operations is:

Receive 24v to W "Call for heat"
Fenwal checks air pressure contacts. If open, energizes blower.
Pressure contacts close from blower pressure, which send the signal to open gas valve (Unit wont send the gas unless the blower is running)
Fenwal sees gas valve open energizes ignitor until flame is detected

I feel my fenwal blower relay is bad and not starting the blower to close the pressure switch, so it isnt sending the signal to open the gas valve. The ignitor circuit at 90v is odd however. Also this may not be true, as when i had the blower jumped out to power it I still didnt get heat from the exhaust of the unit.

Ignitor is energized well before the gas valve is opened. Hot surface ignition.

 

[NickPSI]

Ignitor is energized well before the gas valve is opened. Hot surface ignition.

I see that now I was reading the manual for a different fenwal for a different ignition system. The 35-66 energizes the ignitor and then the gas valve. However, it still should energize the blower first and this isn't sending any voltage to f2 so I believe the internal relay is toast.

Waiting on my parts and I'll update for anyone who lands here from a Google search.

 

[NickPSI]

Update, finally received my ebay used fenwal and the process appears to be moving along fine, but the ignitor isn't glowing, blower comes on and gas valve opens. It's getting 115 at both leads, and measures 120ohms across the terminals but ignitor isn't getting hot???

Has this happened to anyone else?

 

[1poolman1]

Update, finally received my ebay used fenwal and the process appears to be moving along fine, but the ignitor isn't glowing, blower comes on and gas valve opens. It's getting 115 at both leads, and measures 120ohms across the terminals but ignitor isn't getting hot???

Has this happened to anyone else?

Resistance should be lower, between 40 and 75 ohms per Pentair troubleshooting guide.

 

[ajw22]

A new ignitor should read approximately 40-90 ohms.

Get the new style igniter. Read Jandy JXI Heaters - Further Reading

 

[NickPSI]

I did not know the design was updated. I ordered the new version so hopefully this finishes everything up. It should.

I opened up my old fenwal and the circuit trace from the relay to the blower terminals was completely nuked. I think the heater was struck by lightning or something over the winter. How could it be perfect all last summer, and this year the ignitor is shattered, the fenwal is burnt, and the power distribution board burnt?

Thanks for everyone's help. I want to keep this updated for those searching in the future.

 

[NickPSI]

@ajw22 @1poolman1 i got the new style igniter, installed it today, ran it, and still no heat. All other operations go through the motions.

What should there be for voltage between the two igniter leads off the fenwal? Both leads test 120v to ground.

This new style igniter ohmd out at 60 ohms. You can plug the igniter in outside of the unit to see if it glows right?

 

[ajw22]

120V and 60 ohms is correct for the igniter.

The igniter should glow with 120V on it.

 

[NickPSI]

120V and 60 ohms is correct for the igniter.

The igniter should glow with 120V on it.

But not 120 across both leads right, 120 to ground on ign/120 and 120 to ground on ign/fs?

 

[ajw22]

But not 120 across both leads right, 120 to ground on ign/120 and 120 to ground on ign/fs?

It should be 120V across the igniter connection. Not tested to ground.

120V circuit is a 120V hot wire and a neutral wire that should have no voltage.

 

[NickPSI]

That explains it then, it's 0 across the terminals.

 

[ajw22]

Show us pics of what you are doing to measure voltage.

Gas valve should not be opening without igniter being powered.

Maybe @swamprat69 can point you in the right direction.

 

[swamprat69]

During the heater attempting to start up, do you have 24 volts between the "GND" terminal and the "PS" terminal on the Fenwal after the blower starts up? That is what initiates the power to the ignitor for it to heat up.

 

[NickPSI]

During the heater attempting to start up, do you have 24 volts between the "GND" terminal and the "PS" terminal on the Fenwal after the blower starts up? That is what initiates the power to the ignitor for it to heat up.

Yes

 

[NickPSI]

Show us pics of what you are doing to measure voltage.

Gas valve should not be opening without igniter being powered.

Maybe @swamprat69 can point you in the right direction.

When I get home from work today Ill get some pics.

You can smell gas from the exhaust after the purge cycle and ignitor warm up cycle. I think my replacement Fenwal is bad because it *thinks* it is powering up the ignitor but it isn't.