oil fired aga kbb fire valve

[andrew]

Is anyone familar with the Teddington KBB fire valve fitted to AGA oil fire cookers. I have just returned from the country pile of a friend. Symptom was gradually dwindling fuel delivery until the flame went out. By a process of elimination and after cleaning the oil galleries in the burner I have a clear fuel delivery to the valve but none from it. The reset button is pushed home.

Is the failure mode shut?

To anyone familiar with old Austin/Morris cars this works on the same principal as the capillary temperature sender and gauges.

An oddity is that the valve is fitted in the kitchen alongside the AGA when the spec seems to indicate the valve should be oustside the building.

AJH

[Dave Liquorice]

Full of crud? That's what stopped oil flow through ours last winter.

It should be with the sensor inside but an awful lot are fitted inside as that is easier.

[Heliotrope Smith]

?????

[Dave Liquorice]

Include the sentence that I'm responding to and I think it becomes clear.

I'm agreeing that "it", the fire valve, should be outside but that the sensor should be inside but that an awful lot (meaning the subject of the sentance, "it", the fire valve) are fitted inside as that is easier.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember andrew saying something like:

Should be, yes.

Regs dictate so, but before the regs lots of them were fitted indoors.

[andrew]

In fact it was clean. The problem was that I think it must have been hit by a hoover, such that it didn't reset properly. This was no problem when everything was ok but when the boiler went out it was manually triggered to check it and, because it is an over centre type device, not pushed home enough to reset it.

Having figured out that and with an unused expensive replacement I re lit the device but the fuel flow is weak and it doesn't seem to react to the thermostat and barely stays alight. The AGA service engineer is booked to visit in the new year.

AJH

[cynic]

Since there are other makes of capillary firestop valve which get called KBB similarly to Hoover being a vacuum cleaner I assume yours really is a KBB. In which case the button may need pressing quite firmly. The oil port is small so you may have dirt or grit clogging the valve. Also are you sure the oil cut-off in the float control box has not tripped off and is the true cause of the restriction. Similarly what about the oil line filter at the tank or in the float control? I have also spent cold miserable hours trying to unfreeze ice pugs in oil lines during freezing weather. Does your oil pipe "dip" anywhere subject to frost en route from tank to burner? (If it is not a KBB at least one competitor requires the "button" to be pulled out to set open)

IF installed to modern OFTEC standards it should but if the oil pipe comes out of a concrete floor indoors the indoor mounting would be acceptable. FWIW very long capillaries (10 metres) are available.

[andrew]

Yes it is a genuine Teddington KBB and yes something had prevented it from being pressed to click.

Please explain this last. The oil control box has two controls, one overides the thermostat by holding open the arm which holds a valve shut when warm, this is on top left as you view the box, the other is the fuel control which is reset by pressing it down for oil flow??

Tank filter is spotless and I wasn't aware there was one in the oil control.

It does but it is flowing freely from the tank and there was no sign of water in the tank outlet filter.

AJH

[cynic]

The fuel control with the reset level will trip sometimes if the BM float box is knocked or the oil level surges above the trip level within the box. There is also a fusible trip device which can only be seen by removing the top plate which has the printing on it. This device is simply a small cube of low temperature melt metal and is there as final defence if the unit catches fire.

Depending on the age of the control it may be behind a screw cap/plug at front bottom or later models had an oval plate with two retaining screws. There is a fine mesh filter tube behind this. Don't damage the ruber joint when accessing it.

We can discount this then if oil flows freely from the pipe end into a temporary receptacle placed just before the KBB

[andrew]

Thanks for that, I'll have a look when I next get up there in the new year.

AJH

[Heliotrope Smith]

Have reread your post and it is clearer now what you meant. It would of course be pointless to have the sensor outside.