Hi - I have a Wallstar oil fired boiler. Just recently it has started tripping out the reset switch due to air in the oil feed pipe.

I can bleed the air out of the pipe by loosening the allen key bolt on the boiler and all the air goes from the see-through pipe which feeds the boiler. Then after 3 or 4 hours of running the heating all the air is back in the pipe again & the boiler trips out.

I called a boiler chap out who replaced a flame sensor (?) and the jet hole thing (sorry!) and said I needed a Tigerloop. Now, I understand what the Tigerloop does but why would this suddenly start happening after running happily for 8 years?

The boiler is about 2m higher than the tank outlet, the total pipe run is approx 4m and there are no inverted loops.

Thanks for your suggestions.

Dominic, April 2008

Thanks T

I'll leave the burner off this weekend and see if the oil falls away. BTW there is a non return valve installed at the boiler end of the pipe run (before the see-through pipe). What is the likelyhood of this being stuck 'open' and the oil returning back down the pipe?

Thanks D

Dominic, April 2008

Hi Dominic,

Sounds as if you have ingress of air somewhere up at the boiler. Try checking all seals, on the pump etc, and joints.

A tiger loop would be a sinple way out, but they shouldn't really be installed in beside the burner, as the nature of the product is to allow the oil to 'air' but also allows oil vapour out so there is always a fire risk.

If the burner is left off (with oil all the way up that see-through pipe) does it fall away after a time, if so I would look to the hose connections as the may be allowing air to pass.
Make sure all fittings and bleed screw are thightened.

Why would this happen after 8 years of happy running, well kero can be quite hard on rubber seals (o rings) and may have well got to the point where one is passing

T, April 2008