Jandy LXI blower does not start

[Lumpux]

I get a FAULT- CHECK IGN CONTROL error on the display.

I followed the LXI Troubleshooting Guide all the way to step 12 (Check Blower). When I check the voltage between the F2 terminal on the Ignition Control and ground (A) I get nothing (same for F1). But, when I test the voltage between (A) and F2 coming from the power distribution board, I get 120V (same for F1). Shouldn't F2 from the PDB be 0? Does this suggest a bad/shorted blower/capacitor or bad PDB?

The Fenwal diagnostic LED only blinks once when restarted. Any ideas?

 

[ajw22]

Did you check the continuity of the F1 and F2 wires between the PDB and Ignition control/Fenwal module?

@swamprat69 may have ideas.

Jandy Heater Troubleshooting Guides for LRZE, LRZM, LXi,LITE 2 LD, LITE 2 LJ, LITE 2 LG, LX OR LT, HiE2, SERIES 1 & 2, HOT SHOT, and DP OIL FIRED heaters.

 

[Lumpux]

Did you check the continuity of the F1 and F2 wires between the PDB and Ignition control/Fenwal module?

@swamprat69 may have ideas.

Jandy Heater Troubleshooting Guides for LRZE, LRZM, LXi,LITE 2 LD, LITE 2 LJ, LITE 2 LG, LX OR LT, HiE2, SERIES 1 & 2, HOT SHOT, and DP OIL FIRED heaters.

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View attachment 524195

Hi @ajw22. I'm getting 120V on F1 & F2 at the Ignition-control side-end of the wires (when I disconnect them from the IGN), so that current is coming with continuity from the PDB. Is it normal to have 120V on both F1 & F2 coming from the PDB?

 

[swamprat69]

I am assuming that during the heater trying to fire up that you are getting a "check ignition control" without the fan/blower starting and everything up to that point is normal start up sequence. Do you get 24V between the ignition control GND terminal and the ignition control W terminal? If you are getting 24V between GND and W on the ignition control during the start up sequence this should close the normally open contacts F1/F2 on the ignition control to power the fan. At this point the voltage reading between F1 and F2 on the ignition control should read 0V if the contacts have closed, If you do not get 0V replace the ignition control, but be aware that there may be a reason for the failure of either the relay contacts or the relay coil (other than normal wear/aging) that may need to be corrected before just replacing the ignition control to prevent failure of the relay on the new ignition control. How old is the heater?
.

 

[Lumpux]

I am assuming that during the heater trying to fire up that you are getting a "check ignition control" without the fan/blower starting and everything up to that point is normal start up sequence. Do you get 24V between the ignition control GND terminal and the ignition control W terminal? If you are getting 24V between GND and W on the ignition control during the start up sequence this should close the normally open contacts F1/F2 on the ignition control to power the fan. At this point the voltage reading between F1 and F2 on the ignition control should read 0V if the contacts have closed, If you do not get 0V replace the ignition control, but be aware that there may be a reason for the failure of either the relay contacts or the relay coil (other than normal wear/aging) that may need to be corrected before just replacing the ignition control to prevent failure of the relay on the new ignition control. How old is the heater?
.

Hi @swamprat69 Yes, I'm getting 24V between GND and W on the ignition control during start up. So, should I be able to check for continuity between F1 and F2 in the ignition control when W gets the 24V?
Yes, my fear is that a short in a faulty blower may end up frying a new ignition control relay.
Can I jump F1/F2 from the PDB to check if the blower works, or should I try to somehow measure the resistance first?

I believe the heater is 14 years old, with sporadic use.

 

[swamprat69]

You can check for continuity with F1/F2 disconnected but realize that you have line voltage at these contacts (turn off power when disconnecting and insulate wires when off of connections). Also note that a poor set of contacts can show continuity with power disconnected, but fail with power applied. I don't know exactly how the PDB connections are wired (voltage change plugs?) but you should be able to jump F1/F2 to start the blower. In looking at blower part # I noticed that the blower motor does use a PSC run capacitor, have you checked this for capacitance within + or - 10% of rating? Also I would check that the blower wheel moves freely and is not frozen or tight. The only other thing would be shorted motor windings ( refer to motor wiring diagram on motor label).

 

[Lumpux]

You can check for continuity with F1/F2 disconnected but realize that you have line voltage at these contacts (turn off power when disconnecting and insulate wires when off of connections). Also note that a poor set of contacts can show continuity with power disconnected, but fail with power applied. I don't know exactly how the PDB connections are wired (voltage change plugs?) but you should be able to jump F1/F2 to start the blower. In looking at blower part # I noticed that the blower motor does use a PSC run capacitor, have you checked this for capacitance within + or - 10% of rating? Also I would check that the blower wheel moves freely and is not frozen or tight. The only other thing would be shorted motor windings ( refer to motor wiring diagram on motor label).

@swamprat69 The blower works fine when jumping F1/F2; and as expected there is no continuity in the ignition control side (F1/F2).

I know the ignition control is getting power because the LED does blinks (once) when restarted. Is it possible that a faulty sensor reading or something else connected to the ignition control is halting the start sequence (relay close)? or should the relay close to start blowing as soon as the heating sequence starts? Based on the troubleshooting it seems the blower-start is the first step in the sequence.

BTW Not sure if related but I noticed the return from the High Limits sensors to the PIB is 17V (vs the source 26V). Can I temporarily bypass the High limit by jumping J17 @ the PIB or do I need to use a resistance?

 

[swamprat69]

1 Flash on the ignition control is an airflow fault because the blower is not starting. This only tells you that there is a problem in the 24V circuit (airflow switch is not closing due to the blower not running). You need to replace the Fenwal ignition control, but also need to confirm that the problem with the blower relay contacts is due to "wear and tear/age" rather than a problem with the blower motor. Since the blower starts and runs when F1/F2 is jumped, I would also confirm that the capacitor is within + or- 10% of the nameplate rating and the Amp draw of the running blower motor is below the nameplate rating. You will probably not kill the new Fenwal by just replacing it, but at the same time do not want a straining blower motor to contribute to the early demise of the new Fenwal.

 

[Lumpux]

1 Flash on the ignition control is an airflow fault because the blower is not starting. This only tells you that there is a problem in the 24V circuit (airflow switch is not closing due to the blower not running). You need to replace the Fenwal ignition control, but also need to confirm that the problem with the blower relay contacts is due to "wear and tear/age" rather than a problem with the blower motor. Since the blower starts and runs when F1/F2 is jumped, I would also confirm that the capacitor is within + or- 10% of the nameplate rating and the Amp draw of the running blower motor is below the nameplate rating. You will probably not kill the new Fenwal by just replacing it, but at the same time do not want a straining blower motor to contribute to the early demise of the new Fenwal.

I will probably order a new ignition control and test the capacitor.

Do you know if it is possible to bypass the High limit by jumping J17 @ the PIB?

 

[swamprat69]

Never bypass safeties. They are there for a reason. If you have a significant voltage drop across the safety, replace the safety.

 

[Lumpux]

Never bypass safeties. They are there for a reason. If you have a significant voltage drop across the safety, replace the safety.

@swamprat69 Agree, the temporal bypass was in the context of testing if that may cause the heating sequence to stop but I was not sure if J17 checks for voltage or resistance. I already ordered new a high-limit and ignition control but will take some time.

 

[Lumpux]

In case it helps anyone, the culprit behind the "FAULT: CHECK IGN CONTROL" error was a faulty high-limit sensor. Even though I didn't receive any "FAULT: HIGH LIMIT" error and there was voltage continuity (17V), one of the sensors was completely damaged. It was a PAIN to extract, so I also ended up replacing the sensor plug (R0456800).