Laars Lite 2 ignition failure

Jun 1, 2016
7
Medina, WA
My older Laars Lite 2 heater fails to ignite. After reading this post ( Teledyne Laars heater troubleshooting ), I checked the following. The igniter resistance measures about 80ohms. When switching on the heater (temp control), the power to the igniter starts at 24AC, then drops to zero within a few seconds. The voltage from the temp control (going into the TH terminal), stays steady at 24AC. Should I try any other tests before trying to find a replacement ignitor control? Thanks in advance!

temp_control.png
 
After searching, I think this may be the manual for your heater with the wiring/connection diagram on page 7... http://shop.solardirect.com/pdf/pool-heaters/gas-pool-heaters/jandy-lite2manual.pdf If you are measuring 120VAC at L1/L2 on the Fenwal ignition control it would mean that your power supply to the heater is 120VAC rather than 240VAC or that you have lost 1 leg of the 240VAC supply. Is your heater supply voltage 120VAC or 240VAC?
 
My older Laars Lite 2 heater fails to ignite. After reading this post ( Teledyne Laars heater troubleshooting ), I checked the following. The igniter resistance measures about 80ohms. When switching on the heater (temp control), the power to the igniter starts at 24AC, then drops to zero within a few seconds. The voltage from the temp control (going into the TH terminal), stays steady at 24AC. Should I try any other tests before trying to find a replacement ignitor control? Thanks in advance!

View attachment 469114
Ignitor voltage should be 120VAC, regardless of 120v or 240v input, and the voltage should remain "on" for 40 seconds according to the label on the Fenwal box.
 
Yes, this heater is wired to 120AC. If I had taken the picture from a different angle you would have seen the igniter connection going to the 120 connection instead of 240. And, yes, the link above does look like the correct manual.
 

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Hmmm... the link above is for a different version of the Fenwal. This newer version had pins instead of blades for a few connectors and there is a merged IGN/FS connection. There is a post on this forum where someone else didn't have much luck converting to this version of the controller (Help with replacement of Fenwel Ignition control in Laars LD ).

Any idea is someone has posted info on how to use this newer fenwal unit for the older Laars heater? I'm not finding my version of the fenwal anywhere (or at least not anywhere I trust). Even the relay is hard to find.
Thanks
 
Hmmm... the link above is for a different version of the Fenwal. This newer version had pins instead of blades for a few connectors and there is a merged IGN/FS connection. There is a post on this forum where someone else didn't have much luck converting to this version of the controller (Help with replacement of Fenwel Ignition control in Laars LD ).

Any idea is someone has posted info on how to use this newer fenwal unit for the older Laars heater? I'm not finding my version of the fenwal anywhere (or at least not anywhere I trust). Even the relay is hard to find.
Thanks
This is the replacement. There are instructions on the site and may come with the unit. The original can be found, but is nearly 3X the cost.
 
Ah.. Thanks for the link to the newer unit with instructions for adapting to my older Laars Lite 2 model. But... I just double-checked everything and now the igniter looks bad (very high resistance). I'm sure it read 80-90 ohms the other day but it is definitely not right now. So I am going to try replacing the igniter first.
 
The new ignitor arrived today. I installed the new ignitor and the heater now fires up. But I am wondering why the previous ignitor went bad. I installed a new one early last summer. The original ignitor lasted for a decade but the one that just died only lasted a few months. When I replaced it last summer I noticed that the metal cage which fits around the ignitor had rusted away. So I suspect the latest ignitor suffered either due to lack of protection from the burner flame OR perhaps the ignitor was too loose in the housing and slipped out of place (into contact with some other part of the heater). Any thoughts on the possible cause of the latest failure?
 
The quality and longevity of many parts have declined in the last decade.
 
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