10-25-2018 08:05 PM
Have you measured the actual current going to the heater?
You have replaced the relay, the base or both 5 times?
What voltage are you running to the heater?
Relay per data sheet is rated 20Amps at 150VAC for resistive loads.
Would be helpful to know how it is actually wired.
What are the heat specifics? Convection or installed with a pump? How many watts?
More info may get you a better answer