Jandy heater igniter burning up

[Frank Cowart]

I have a Jandy model zodiac lrz Electronic Heater Model Number: LRZ400ENN that was giving the message "FAULTCHECK IGN CONTROL".
The Fenwal automatic ignition system was bad and so was the Hot Surface Igniter. I replaced both and the heater worked for about 1 hr, before the igniter burned up and blew the circuit board on the ignition system.
It seems as though the igniter isn't turning off after the heater starts. I've already wasted about $200, so any help is much appreciated.

 

[ajw22]

@swamprat69 may have ideas.

Any signs that you had rodents partying in the heater?

 

[swamprat69]

Photos of the heater wiring and controls and burner compartment with the cover off would be helpful. Also photos of the original Fenwal control and ignitor along with the replacement Fenwal control and ignitor. Throwing parts at a heater without troubleshooting first can be a hit and miss situation. As far as I can see, this would be the manual for your heater https://www.jandy.ca/-/media/zodiac/global/downloads/h/h0299500.pdf. If so, the original problem may have been as simple as a dirty flame sensor, but there is no way to tell without troubleshooting first. Do you have a multimeter and do you feel safe comfortable using it?

 

[Frank Cowart]

Thanks for the information. I have the manual and the heater troubleshooting guide and I have a multimeter.
Some more information: I had to replace the ignition system and the ignitor because they were actually destroyed, not because of the diagnostic error.
I've had a lot of problems with this heater over the years and I have replaced the flame sensor, but I think it was preventing it starting, if I remember correctly.
Here are the parts: Fenwal automatic ignition system catalog numer:35-652933-115.
Hot Surface Igniter: R0457501Jandy LRZE
Bestwill corp.Transformer model E0180500
I've included the transformer because I checked it and it is outputting 29 VAC and it should be 24 VAC.
Since the ignition system and igniter were destroyed, I ordered new ones and a new transformer.
Also attached is the circuit board from the ignition system and you can see that it is burnt on the L1 terminal.
Do you think the 29VAC instead of 24VAC could be my problem? Also, does the flame sensor cause the ignition control to turn off the igniter when a flame is detected?
Thanks,
Frank

 

[swamprat69]

The 29V measured should not normally be a problem. There is an allowable + or - voltage built in to most electrical/electronic components. There is also a + or - margin of error in any multimeter. Things to be aware of! The spiral style silicon carbide ignitor is very fragile. Even a slight tap/bump against a hard surface can cause it to fail in a short time. Touching the black crystalized surface of a silicon carbide ignitor and transferring the oils present on your hands can cause the ignitor to fail in a short time much like touching the glass surface of a halogen lightbulb. Cold resistance (75 deg. + or - 10 deg. F) should be approx. 40-100 ohms. The L1/L2 terminals on the Fenwal supply power only to the ignitor itself and if burnt out would indicate either a fault in the circuit board or over amperage to the ignitor. The power to the ignitor is timed from the Fenwal including warm up (40 sec.) and trial for IGNITION ( 10 sec.) The flame sensor is only used to prove that flame has been established during the IGNITION time (10 sec.) while the gas valve is powered and open.

 

[Frank Cowart]

Thank you very much. I was very careful not to touch the igniter coil when installing it. Do you think I could put a fuse between the LI terminal and the ignitor.
At $150 a pop, it gets expensive.
Thanks again,
Frank

 

[swamprat69]

Ohms law states that I=V/R. Excessive amp draw (I) through the ignitor circuit would be caused by either lower resistance through the ignitor (R) or higher voltage (V) supplied to the ignitor. Check that the ignitor resistance is 40-100 ohms. I believe that your heater has 240V power supply, so make sure that your ignitor leads are attached at IGN/FS and IGN/240 and not at IGN/FS and IGN/120. Normal amp draw for the ignitor should be approx. 3-5 amps.

 

[Frank Cowart]

Thank you,
I will do this. The only difference in the way I'm wiring it is that the flame sensor is wired to IGN/FS and the ignitor is wired to IGN/240 and off of the terminal block for the transformer.
Also, thank you for your service. I graduated from high school in 69 but thank God I didn't have to go to VietNam.
Thanks again.
Frank

 

[swamprat69]

You are correct, I was thinking of some of the early Fenwals that had the flame sensor tapped into 1 leg of the ignitor power.

 

[Frank Cowart]

Thanks for all of your help. I wish we had a technician in this area with your expertise. Attached is a troubleshooting guide that I found, after a lot of searching, that might come in handy for you when helping people with Jandy heater problems.
I'm going to do as you suggested and check the ohms on the igniter. I've checked the voltage on the wire going from the terminal board to L1 and the other wire going to the surface igniter and they are both 120V. I'm going to put a 5 amp inline fuse on each of these wires and maybe that will prevent them from burning up.
Thanks again,
Frank