My Trianco Eurostar 110 STD oil boiler is about 10 years old and has worked without problems all that time. It is fitted with a Stirling 50 burner and has a balanced flue which goes straight out through the wall behind it. Oil is supplied via a Tiger Loop.
Earlier this year it started locking out. Our original engineer has retired so an alternative engineer (recommended by a neighbour) was called. He allegedly did all the usual tests and reported that he could not locate the basic source of the problem. If the air inlet hose is removed from the balanced flue box, it runs reliably. He left it running without the hose until his next visit whereupon he started converting the boiler to a 'conventional flue type' by drilling a 110mm hole through the 20 inch barn wall. Even this extreme measure failed because if the air inlet hose is extended by a further 6 inches, the burner pulsates for a second or so and then locks out. We have been left with a hefty bill for the hole (not yet paid) and he seems to have given up trying further.
The inside of the boiler is relatively soot free, the exhaust gas looks clean. The air damper is set to 14. I have tried adjusting it between 19 and 12 but it does not make any difference to the locking-out point if any additional restriction is added to the air inlet hose.
The engineer is supposed to have checked the oil filters but I am wondering if he has done the job properly. The oil pipe length and suction height are within specs for the Tiger loop and nozzle but has not a lot of capacity in hand. Can anyone advise if the above symptoms are consistent with a restriction in the oil supply please.
Earlier this year it started locking out. Our original engineer has retired so an alternative engineer (recommended by a neighbour) was called. He allegedly did all the usual tests and reported that he could not locate the basic source of the problem. If the air inlet hose is removed from the balanced flue box, it runs reliably. He left it running without the hose until his next visit whereupon he started converting the boiler to a 'conventional flue type' by drilling a 110mm hole through the 20 inch barn wall. Even this extreme measure failed because if the air inlet hose is extended by a further 6 inches, the burner pulsates for a second or so and then locks out. We have been left with a hefty bill for the hole (not yet paid) and he seems to have given up trying further.
The inside of the boiler is relatively soot free, the exhaust gas looks clean. The air damper is set to 14. I have tried adjusting it between 19 and 12 but it does not make any difference to the locking-out point if any additional restriction is added to the air inlet hose.
The engineer is supposed to have checked the oil filters but I am wondering if he has done the job properly. The oil pipe length and suction height are within specs for the Tiger loop and nozzle but has not a lot of capacity in hand. Can anyone advise if the above symptoms are consistent with a restriction in the oil supply please.