Hi All,
Quiet a while since I have been on this site. I have been running a waste oil burner for over 10 years here in Ireland and have sorted out all the little problems that can cause your system to shut off etc. To avoid having no heat if and when a problem occurs with my waste oil burner I re-installed my regular diesel boiler as a standby system. Both boilers are plumbed on my house system, however I designed and built a simple circuit which will start the standby boiler if the waste oil burner cuts out and goes into a fault condition. By doing this my house will always have heat. I installed a small neon light in my kitchen which informs my when I am running on the standby system. One frequent problem that happens is the siphon nozzle can get blocked. I discovered that the in-line filter that supplies the burner will not take care of this 100% as some of the blockages occur when fine particles that build up on the pre-heating element become dislodged, and eventually block the nozzle. I fixed this by making a fine sieve from a brass sheet ( 100 micron's ) filter mesh, which is about the size of a shot gun cartridge. I placed this around the pick up pipe in the pre-heat chamber. I chose brass as you can solder this material when you have shaped it to suit your setup. Now I have zero nozzle blockages. Well over the last 4 month or so. Hope this helps others .