Help with BM Oil Control Valve (Aga)

[Vaporiser]

Hi, I'm hoping someone may be able to help with this: I just completed a "normal" service on our oil fired Aga, i.e. removing carbon deposits and ensuring the supply pipe is clear. I managed to light it and it stayed lit for a few hours then died and now won't relight.

This may be relevant - we had a new oil tank fitted in the summer because the old one developed a split and this is the first time I've tried to start the Aga since having the new tank. Our oil fired boiler for central heating is working normally.

I'm wondering if the filter may be blocked in the BM-type OCV.
Question: If I flick the arming lever up to shut off the flow, does that mean I'll be able to undo the 2 retaining screws to get access to the filter without flooding the kitchen with oil, or do I need to isolate it at the tank first?

Thanks in advance, I'd appreciate any advice.

 

[ShaunCorbs]

Didn’t they purge the oil through?

 

[SJB060685]

I suspect a fuel issue as well based on the above. Flicking the lever will just close the needle valve which is downstream of the filter, you will need to isolate at the tank or a valve before the OCV and catch whatever comes out in a container when you release the two screws and remove the filter.

 

[Vaporiser]

Thanks SJB for replying so quickly. You've confirmed what I thought. I'll have time tomorrow to check the filter and I'll update this thread.

 

[Vaporiser]

Didn’t they purge the oil through?

Hi Shaun. I'm not sure. They may have done on the feed to the boiler but I don't think they did anything at the Aga end.

 

[SJB060685]

Do that and update us yes. There are a number of other possibilities but let's rule out fuel delivery first.

 

[Vaporiser]

Ok so I checked the filter and it was pretty dirty - see image.

I cleaned it with kerosene and replaced it. However there is no flow from the OCV to the burner. I verified that fuel is getting to the OCV by slightly loosening the filter plate and seeing the oil dripping into the container that I had placed. I then removed the feed tube to the burner and observed to see if oil was flowing but sadly it isn't, after more than an hour.

Any suggestions please?

 

[SJB060685]

You've cleaned the filter with the correct method and by the looks of it there was a lot of c^@p the filter had collected. You say you disconnected the feed line from control valve to burner tube and nothing come out from the bottom of the OCV? This leads me to suspect the metering stem is clogged as well, providing you have proved the valve does actually contain oil?
The metering stem is a little piece of metal with a hairline groove cut into it to meter the flow of oil, unfortunately this hairline groove can get clogged quite readily, even hair from pets that has found its way in is enough to block it.
Unfortunately for you I would not suggest removing and checking yourself, as if you get it wrong when replacing you can flood the burner with no control over flow, a lit burner in this case is a NO NO.

 

[Vaporiser]

Hi SJB, thanks again for the quick reply. I guess it's time for me to hand this over to someone qualified. Thanks for your input, when I get to the bottom of it (most likely in the new year now) I'll post an update.

 

[SJB060685]

Like I said mate, I suspect that is the problem, providing you have confirmed oil into the BM valve. Im sorry me telling you I wont guide you through this any further is not what you want to hear but there's potential for it to go wrong and I would never live with myself if it did, especially on Christmas day and to be honest even if you got it running tonight it might not be fully upto temp for your Christmas meal tomorrow. I hope you have another means of cooking. Have a good Christmas and update us when you can.

 

[Vaporiser]

Like I said mate, I suspect that is the problem, providing you have confirmed oil into the BM valve. Im sorry me telling you I wont guide you through this any further is not what you want to hear but there's potential for it to go wrong and I would never live with myself if it did, especially on Christmas day and to be honest even if you got it running tonight it might not be fully upto temp for your Christmas meal tomorrow. I hope you have another means of cooking. Have a good Christmas and update us when you can.

Thanks for the sage advice SJB. Luckily we aren't relying on it to cook Christmas dinner. Have a great Christmas and I'll update in the new year.

 

[Vaporiser]

Thanks for the sage advice SJB. Luckily we aren't relying on it to cook Christmas dinner. Have a great Christmas and I'll update in the new year.

Just to update: We had an Aga specialist out and the problem was indeed caused by the metering stem being blocked. Thanks to SJB for correctly diagnosing the problem.

 

[SJB060685]

Glad you have it fixed 👍