PID help

[ageingrodder]

I consider myself a guy of reasonable mechanical ability and knowledge, but I am having a hard time wrapping my head around PID's.    I intend to use a PID to control my nozzle heater and have been thinking the PID would come on when there was a demand for heat.  Would I be better off to have the PID hold a constant line temperature of, say 160* whether there was a call from the thermostat or not?  Seems to me this would eliminate the lag time for the system to heat the fuel before ignition.  It should also simplify the wiring schematic.  Am I missing something?

[Dead Eye]

 Ummmmm No don't keep the heat on because it will cook inside the nozzle and polymerize , then its clean or replace nozzle time. 

[Russ]

Yes, what Dead Eye said.  The PID I use has an alarm contact that is normally open and closes at a set temp, turning the burner on.  I havent automated my system to this point yet, but the alarm function is there.  Although this wont help with the lag time.

[ageingrodder]

Thanks for the reply's.  

Since I posted the question, I bought and installed a PID using the alarm to activate the ignition system.  That part of my system works well.

Now my problem is I have given up on the pressure system and am going to switch to siphon.  It appears  the switch is not going to be quite as easy as i had hoped.  Got some reading to do.