I wonder if anyone can help me. The oil level in the BM valve on the side of my Rayburn seems to have dropped as it now doesn't see to be high enough to enable the oil to reach the wicks in the burner unit. Oil flow appears fine but the flow stops before it reaches the main part of the burner, stopping just below. I did run out of oil (and had some water in the system) but all is flushed through now and it all seems a bit unusual.
Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws
View the thread, titled "Low Oil level in Rayburn BM valve?" which is posted in Boiler Advice Forum on UK Plumbers Forums.
If water gets into the system then you will have emulsified oil in places. I suspect there is a restriction somewhere causing a lack of flow to/through the needle valve. Any strainers at tank, in-line filters and filter in your BM control valve need to checked again, also if water has corroded anything inside this is likely to be a BM Control replacement, however I suspect it’s just a blockage in this case. You can adjust the oil level in these valves but these are mechanical settings and unless someone has fiddled then I doubt it’s that.Do you have an oil boiler coming off tank as well, if so does that run fine?
The carbon leg blocked will cause a little to no flow to burner Best, however the OP is suggesting that the level in oil control is too low. I’m inclined to believe it’s one of what I mentioned above as the inner workings of these are mechanical as you know and unless riddled with shouldn’t alter. The OP needs to dip the tank again for evidence of water still there, or more. Then he needs to check strainers, in-line filters and the filter into valve as well like you say. Emulsified oil is a milky white colour and should be easy to spot. I once saw a Toby valve with about half in of emulsified oil in the bottom, obviously the fire wasn’t staying lit, I removed control valve and removed all crap, reinstated and away she went.
Yes I know buddy. The carbon leg could be blocked as well but what is certain is he has a problem before fuel even goes through the metering stem. I have known some older engineers fashion a guard to put over carbon leg or wrap in tin foil to deflect heat away and stop the carbon forming where’s it’s not wanted (I believe the deep well burners are more susceptible to this).
If the OP responds we can take it from there
If the OP responds we can take it from there
Thanks for these suggestions. The Rayburn was working pretty well before and, as far as I can tell, no adjustments have been made. I have cleaned out all the burner pipework and the narrow slot in the valve unit seems fine. Clean oil is coming through to the burner tray just not high enough. Should the oil level in the BM valve coincide with the level of oil in the burner?
That's what I thought. It seems as if the float valve is not allowing a sufficient depth of oil into the valve. Is there an approximate depth of oil that I might expect? It looks to be about 1 1/4 inches or thereabouts. Could any float valve adjustments have been knocked out of position? As it was ok before I am wary of making any major adjustments to the valve height that might cause issues in the future.
There is actually two floats which control the needle valve, which is what controls the flow of oil into the valve. Sorry to sound like a t**t, I don’t mean to but you clearly don’t understand this valve do you. Adjusting the control valve height isn’t going to fix your problem. The valve under normal working conditions will always fill to a set line, you can see these indicators inside the oil control valve.
If you take the lid off you should see two fill lines, a min and max? I’m assuming the floats are sitting on top of the oil? And not stuck in the air? Whilst there trying pushing the float up and down a few times, I believe air can get trapped in needle valve or some crap and doing this might dislodge it.
Which OC Valve do you have, is it a BM?
If it's a BM valve they are fairly 'idiot proof' and usually work quietly for many years with minimal maintenance.
1st thing is to check the level inside the valve body, if this is below the level marker check the tank filter...top of the list for slow filling or zero filling (especially if it has been contaminated with dirty oil or oil /water)
If the oil is to level in the valve body, next on the list is the 'coke tube' and the reservoir in the burner base, these do clog up with carbon badly which can stem or halt the oil feed completely.
DO NOT attempt ANY checking with the unit alight......Turn it off first and let it cool down.....takes about 2-3 hours.
Having said that you do need to be fairly competent/confident to de able to reassemble the burner properly you do not want any leaks.
If you are not confident enough get an engineer out.
Last edited:
Official Sponsors of Plumbers Talk
Reply to the thread, titled "Low Oil level in Rayburn BM valve?" which is posted in Boiler Advice Forum on Electricians Forums.
Similar plumbing topics
We recommend City Plumbing Supplies, BES, and Plumbing Superstore for all plumbing supplies.
