Worcester Heatslave 15/19 runs then locks out

[Burnerman]

Just a thought Mr. S - the motors on this B9B burner have very little starting torque, and you'll notice that the pump is held into the casing with 3 grub screws.
If these are inadvertently tightened, the pump moves out of alignment just a fraction, binds, and can cause difficult start up. I find the minimum screw pressure helps things.
John

 

[Sheepish_too]

Well just to update. Yesterday I reset the lockout about 5 times. Was doing it because I was getting some warmth out of the radiators and meant we had hot water. The lockout was becoming increasingly less frequent, such that I last reset it at around 16:00 yesterday and it's run for about 21 hours now. I can only think there was some muck in the oil that has worked its way through the system. I have a new nozzle now so I'll change that at the weekend as a matter of course.

How would water in the oil manifest itself? Not that I think there is so much water in my tank it fills the base up to the point the outflow pipe connects.

 

[Burnerman]

Usually any water is visible in the filter settling bowl, right back at the tank valve.
If that remains clean, then water isn't an issue but taking an oil sample after the filter and allowing it to settle isn't a bad move. Water kills fuel pumps, big time!
Your initial symptoms did point at fuel starvation but you said you were happy enough with the oil flow......fair enough. Anyway - fingers crossed! We appreciate the update, and lets know what happens.
John

 

[oilhead]

There is filter in your oil pump, either under an allen screw adjacent to a little picture of a filter, or beneath the front cover accessed by removing the front cover. An inspection of this will show if you have water. Draining off through the hose does not always show water.

 

[Terrywookfit]

Very unlikely that a water problem would cure itself !!