Burner truns on and off

[C&T Pressure]

I bought new washer back in december of 2001. When i turn on the berner and everything gets heated up, it shuts down on me then turns back ect. i have no thermostat on machine. can't figure out why it keeps turning on and off. Water never gets hot. I know it should be under warranty, but hate to but in the shop at this time.

 

[Hotwaterwizard]

Take a look at the wiring I'll bet there is a device with wires going to it near the output of the coils near the Quick coupler. That is a High Limit Switch. A nonadjustable Thermostat. It stops the water from getting too hot by shutting the burner on and off. If your water flow is too low this will let you know. So check the water filter on the inlet of the pump. If it is dirty the water will get too hot. If that is not the problem check the fuel filter. Install a new one. If that doesn't work turn down the fuel pressure.

For more check out this link!
Burners 101