Can I convert a telstar model teledyne Laars to propane ?

SOURCE: My teledyne Laars Telstar Model TGS-50 spa heater

Without doing more troubleshooting i would have to say that it is the main board (the board with the knobs on it) Take it out and see if there is any corrosion on it.

SOURCE: i need assistance withlighting my spa

Here is an exploded view. Open the Front panel and you will see a red knob with instructions by it. Press and hold down when you turn it to pilot. The pilot is located down and to your right ( where you light it) hold for 10 seconds then turn to on. The heater is ready for use.
http://www.poolcenter.com/parts_heaters_laars_markv_pg2_poolstor.htm

SOURCE: Pool Heater wont light

NO NO NO the heater is design to work on propane or natural gas only

SOURCE: Teledyne Laars LD250 Propane Pool heater cycles on and back off

Do you replace the thermopile or check the milivolts?
Check the Pressure gas
You need replace all of them terminals and check again the milivolts at the gas valve

SOURCE: can we convert Laars lite llg175N to propane from ...

You can convert this laars with a new burner tray, new gas valve etc..I have lots of customers who was the visa versa to you Natural to LPG and LPG to Natural..I offer an exchange service please see..


http://www.laarsman.co.uk

Miles