I have seen other post about HSI failures. Done my research and tests. Replaced the failed igniter but wondering if failure will repeat. After replacing it got voltage and glowed and heater ignited ok. But HSI remained glowing with furnace operating until I shut it down a couple mins later. I would expect it to shut down. Perhaps this is why my og HSI failed in the first place? However, it was 9 years old. Should the HSI power down after flame is sensed? My heater is Jandy LXi 250NN.
Hot Surface Ignitor Failure
- Thread starter Deek75
- Start date
- Jul 21, 2013
- 52,480
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
swamprat69
Well-known member
A photo of your Fenwal ignition module would be helpful. HSI should be powered off after flame has been proven (there is a specified time after the gas valve is powered to prove flame before retrial for ignition). This could be checked at the Fenwal ignition module leads to the HSI.
Here is my Fenwal unit. Also attached is photo through window. Shows the igniter still glowing at about 2m:4s after energization. I took a video of this sequence and that is where I grabbed this photo. Flame ignited about 40s after initial glow. Which I think is per the manual. You can see the flames in there but igniter still glowing. I think the fenwal is bad? Or maybe something else? I’m trying to prevent having to replace the igniter multiple times by not addressing the root of my problems.
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swamprat69
Well-known member
What heater make and model do you have? Do you have a multimeter and do you feel both 100% safe and comfortable using it? What is the part number for the replacement HSI that you installed?
- Jul 21, 2013
- 52,480
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Jandy LXi250NN ng heater. Yes have multimeter and very comfortable using it. The new HSI is a Jandy - R0457500 - Hot Surface Ignitor. The tip of my failed igniter was flat. This new one is spiral. Installed very carefully. Did not touch the element. Measured 77ohms at ambient room temp before installing.
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swamprat69
Well-known member
After blower starts, 15 sec blower prepurge, 40 sec HSI warmup (HSI powered), gas valve powered for 7 sec in trial for ignition. If burners light off, power to HSI should drop out (can be checked between IGN/120 and IGN/FS on the Fenwal) or with a clamp around ammeter on either wire from those terminals ( should read ~ 3.5-5 amps if powered). I believe that the spiral ignitor was the original part on older JXi's and the flat ignitor was a revision replacement. Don't know if there was a specific reason for this, but the flat ignitors do tend to be a little "hardier". Either should work though as long as the ceramic ignitor mount is the same.
swamprat69
Well-known member
Not sure if I am looking at the correct wiring diagram, but it is showing a separate flame sensor tapped in to the ignitor IGN/FS wire. Originally flame was sensed only through the HSI on these Fenwals, but this caused intermittent false "no flame" sensing problems which was why the separate flame sensor was added.
Yeah interesting. I tried to find the flat igniter but most seemed to be the spiral type. It fit just fine and is installed ok. It powers up and will ignite but based on the image I attached above, 2 mins in to the call for heat it was still glowing and I would have expected it to shut down. I have the manual for this unit and diagram attached: it does have separate flame sensor installed. I wonder if that has an issue? But not sure it does. As it allows the heater to continue heating. If it had an issue then it would call for the heater to shut down.
Attachments
Yeah interesting. I tried to find the flat igniter but most seemed to be the spiral type. It fit just fine and is installed ok. It powers up and will ignite but based on the image I attached above, 2 mins in to the call for heat it was still glowing and I would have expected it to shut down. I have the manual for this unit and diagram attached: it does have separate flame sensor installed. I wonder if that has an issue? But not sure it does. As it allows the heater to continue heating. If it had an issue then it would call for the heater to shut down.
The style, flat or spiral, has little to do with the issue. The spiral is found alot but you can still find and get the flat style.
If the issue was the flame sensor, meaning it was not operating correctly, the heater would shut down. Assuming someone has tampered with things and bypassed it.
If you really want to test, then once the heater ignites, you can unplug the igniter from the Fenwal. The unit may shutdown though when you do this.
If the issue was the flame sensor, meaning it was not operating correctly, the heater would shut down. Assuming someone has tampered with things and bypassed it.
If you really want to test, then once the heater ignites, you can unplug the igniter from the Fenwal. The unit may shutdown though when you do this.