I have a raypak rp2100 digital. Tested it for the spring startup and it fails for "plt" or pilot. I noticed the slab it is sitting on is wet while pool pump is on and dries up when off. Pulled front cover and the lowest area is rusty looking and wet. What might I be looking at as the root cause?

You may want to make certain that the pump is running ( moving water into the heater ) in order to activate the heater. The heater will not try to fire without water moving through it. PLT code means that the Pilot is trying to ignite. If you see nothing on the display, you may want to verify voltage.They are typically wired on the same circuit. Therefore if one has correct power ( activated ) than so should the other.

spk I think means spark for ignition and plt means pilot so i assume the heater tried to light but the pilot light is not staying on. could be dirtly contact on the ignition spark plug or dirty pilot flame need to be cleaned and the unit serviced.

i hope this was useful.

Plt means pilot light failure. the heater has failed to ignite. either the ignition unit needs cleaning or replacement or the pilot light valve where the flame is, has got dirty and needs a service.

recoment you get a heating service engineer to have a look at it.

i hope this was useful.

In models older than 07-07 it typically indicates a loss of the pilot light.
In models newer than 07-07 it is probably the air switch not being activated, or it has just failed. Check air switch tubing for secure connections.

Probably no need to replace pilot. Just clean it. If your Raypack (mine is a 2100 but most have the same electronic ignition pilot) lights and runs for about 2-5 minutes an then shuts off, you need to clean the pilot sensor. The pilot sensor tells the unit the Burners are running. If the pilot sensor becomes corroded, carbon, etc. the unit will light but will shut off after a few minutes as it thinks the unit is not operating properly. The unit will try to re light, but fail, and then PLT will show on the main programming screen. To fix the probelm, shut off the unit power. Remove the pilot assembly which is located at the bottom right of the unit. There is one screw holding the pilot assembly in place. Gently remove the pilot assembly. There is a fork like probe sensor (not the one with ignition and gas feed) that needs to be cleaned. Take some rough sand paper and clean it thoroughly. Re insert pilot assembly and fire the unit. If this fails, clean the sensor again. Problem solved!

If your Raypack (mine is a 2100 but most have the same electronic ignition pilot) lights and runs for about 2-5 minutes an then shuts off, you need to clean the pilot sensor. The pilot sensor tells the unit the Burners are running. If the pilot sensor becomes corroded, carbon, etc. the unit will light but will shut off after a few minutes as it thinks the unit is not operating properly. The unit will try to re light, but fail, and then PLT will show on the main programming screen. To fix the probelm, shut off the unit power. Remove the pilot assembly which is located at the bottom right of the unit. There is one screw holding the pilot assembly in place. Gently remove the pilot assembly. There is a fork like probe sensor (not the one with ignition and gas feed) that needs to be cleaned. Take some rough sand paper and clean it thoroughly. Re insert pilot assembly and fire the unit. If this fails, clean the sensor again. Problem solved!

Be sure to open the gas line at the heater and turn on at local valve to bleed the line. Let run for a few seconds till you smell gas. Close valve and close line then let sit for a few minutes till gas clears and try to light again. Let me know how you do and good luck.

Is it a cartridge filter? If so, get a new element.

The 'thermocouple' might not be working. Is the pilot light staying lit? The therm. sends a millivolt signal to the control insuring a pilot is lit.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/craig_3fa289bf857b1a3c

Well your right it is your ignighter the spk is spark the plt piolet light this pc is about 200 .

THANK YOU FOR USEING FIXYA
RATE ME