six weeks, six visits, still no working boiler

[Tomswan]

That sounds reasonable as these oil pumps are capable of significant suction ( a vacuum gauge is plugged into the pump port marked V to determine this.)
However, if you have a good gravity supply down to the burner all should be well.
I’d try to seal up any suspect areas when you can - there should be no kero leaks at all.
John

Well, I am speculating that the rubber seal/ 0 ring in the filter bowl is not perfectly situated, and that suction from the pump is creating the gap.

Then again, maybe not. I will know when I check for air.

 

[Burnerman]

I guess in your case if you had a tiger loop you could see if air is being drawn in.....I’m assuming the system used to behave?
John

 

[Tomswan]

I guess in your case if you had a tiger loop you could see if air is being drawn in.....I’m assuming the system used to behave?
John

Yes, for years. However, the flue gasses never smelled particularly clean. I heard that boilers were often 'smelly' and thought no more about it. More is the pity.

I should know if there is air ingress if I bleed the system at the burner port. Any air that has entered will escape at that point.
Now I have forgotten if I can do this with everything turned off. Must be possible, surely, since air locks cause burner lockout.

Easy enough to check though.

 

[Burnerman]

I’d crack open the joint where the flexible pipe enters the pump first - any air there should fizz out.
The burner should now start but maybe some more air could vent through port P - pump running.
John

 

[Tomswan]

I’d crack open the joint where the flexible pipe enters the pump first - any air there should fizz out.
The burner should now start but maybe some more air could vent through port P - pump running.
John

That's great, thank you John, I will do exactly that.

I suppose I should also bleed at the filter housing. If the air is collecting there it would stop the flow of oil and cause lockout. I have to assume that is possible otherwise why put the bleed screws on the filter housing?

 

[Burnerman]

Yep, there are usually two bleed screws on the top of the filter, crack both of them open. Normally this just needs to be done after a filter change, of course.
John

 

[Tomswan]

Yep, there are usually two bleed screws on the top of the filter, crack both of them open. Normally this just needs to be done after a filter change, of course.
John

I have to assume he did that, but if air is being sucked in at that point it will need doing again.

I must confess that those around me have been urging me, out of exasperation I do believe, to 'get a new boiler', but if anything the events to date have shown it is the boiler that is working perfectly. It is firing when it should, and it is locking out when it should. The built-in safety systems are operating within their designed parameters. Human error is at the root of my problems here.

 

[oilhead]

If your tank is above the height of the burner, then any filter along the way will leak. I doubt very much if you are sucking in air, but certainly cure the leak. A filter that is fed by gravity will leak all the time if there is a slack joint. What is this filter like? Does it have any names on it like crosland? There may be a bleed screw, but many filters are self bleeding. A picture would help.
If you have a slack joint, a Tiger Loop will not cure it; in fact it will exacerbate the problem, but the bubbles in it will give you a clue. It would also be helpful if you ever run out of oil as it would self prime. Don't go off on a tangent comparing your burner with an automotive diesel engine, it will confuse you even more. I scanned through the thread again. What parts have been changed? Pump? Motor?
What is the distance between your tank and the boiler? What size is the oil supply pipe? After changing your filter, purge the oil line by running off 2 - 3 litres. You may find the supply stutters. If you have a foot pump and are able to adapt your pipe with hoses or tubes, then disconnect both ends and blow through to clear any sludge that may have accumulated in the pipe. If that pipe is 10mm copper and buried, you have no idea how much it undulates.

 

[Tomswan]

If your tank is above the height of the burner, then any filter along the way will leak. I doubt very much if you are sucking in air, but certainly cure the leak. A filter that is fed by gravity will leak all the time if there is a slack joint. What is this filter like? Does it have any names on it like crosland? There may be a bleed screw, but many filters are self bleeding. A picture would help.
If you have a slack joint, a Tiger Loop will not cure it; in fact it will exacerbate the problem, but the bubbles in it will give you a clue. It would also be helpful if you ever run out of oil as it would self prime. Don't go off on a tangent comparing your burner with an automotive diesel engine, it will confuse you even more. I scanned through the thread again. What parts have been changed? Pump? Motor?
What is the distance between your tank and the boiler? What size is the oil supply pipe? After changing your filter, purge the oil line by running off 2 - 3 litres. You may find the supply stutters. If you have a foot pump and are able to adapt your pipe with hoses or tubes, then disconnect both ends and blow through to clear any sludge that may have accumulated in the pipe. If that pipe is 10mm copper and buried, you have no idea how much it undulates.

There's too much info for anyone new to the thread to wade through. The filter near the boiler is bowl filter with two bleed screws. I will be looking at that in the morning. The filter was swapped a couple of days ago but I left a drip tray underneath the filter and some kerosene has leaked out into the tray, so I know there is a leak there. However, it is not leaking when the boiler is not running, which seems to suggest the pump is sucking in air. I will find out tomorrow anyway by bleeding the system, re-fitting the filter bowl, leaving the tray in place, and waiting to see if any more kerosene leaks out. If it doesn't then I am sorted with a bit of luck. It may be a simple as the 0 ring in the filter bowl being slightly misaligned when it was all tightened up.

Good point about draining some oil off. I was thinking of doing that anyway to see what sort of state it is in (cloudy or clear).

There `are other threads on the internet that suggest wax/particle dropout is possible at milder temperatures than is officially recognised for kerosene, so it is possible I suppose that the remaining cold weather over the weekend has repeated what happened earlier on, and that I will find green film on the nozzle filter again as a result (if the is the actual cause of it and not crap from the original filter).

However, this may just be lockout due to air. Thanks for the input.

 

[Tomswan]

If your tank is above the height of the burner, then any filter along the way will leak. I doubt very much if you are sucking in air, but certainly cure the leak. A filter that is fed by gravity will leak all the time if there is a slack joint. What is this filter like? Does it have any names on it like crosland? There may be a bleed screw, but many filters are self bleeding. A picture would help.
If you have a slack joint, a Tiger Loop will not cure it; in fact it will exacerbate the problem, but the bubbles in it will give you a clue. It would also be helpful if you ever run out of oil as it would self prime. Don't go off on a tangent comparing your burner with an automotive diesel engine, it will confuse you even more. I scanned through the thread again. What parts have been changed? Pump? Motor?
What is the distance between your tank and the boiler? What size is the oil supply pipe? After changing your filter, purge the oil line by running off 2 - 3 litres. You may find the supply stutters. If you have a foot pump and are able to adapt your pipe with hoses or tubes, then disconnect both ends and blow through to clear any sludge that may have accumulated in the pipe. If that pipe is 10mm copper and buried, you have no idea how much it undulates.

Actually there is a lot of useful information there, so thanks again. It is buried copper pipe, and I had no idea it would undulate, but makes sense. Great idea to blow through the pipe with a foot pump. I may be able to rig that up. I'm hoping the filter near the boiler would catch any accumulated crap in the pipe though. It will be interesting to see what sort of state it is in in the morning. If it has gone black again then all good, I know where I am - crap in the pipe. The tank is new, and the filter at the tank outlet has not been clogged, so it would have to be n the pipe.

 

[Tomswan]

Here's a thought: what if I remove the filter bowl at the tank outlet and fill it with an additive that breaks up deposits? Anyone done that to flush the pipeline?

 

[oilhead]

Can't think what additive would work. Your leaking filter sound slike Crosland, so bleed through the two screws. I would be worried that it only leaks when running as it suggests that gravity flow is not good.

 

[Tomswan]

Can't think what additive would work. Your leaking filter sound slike Crosland, so bleed through the two screws. I would be worried that it only leaks when running as it suggests that gravity flow is not good.

Ok, thanks. It ran fine for seven years that I know and probably longer without leaking at all, so I hope the gravity flow is ok. I'd also hope one of the engineers who came out would have picked up on poor gravity flow. Then again if there is some junk in the pipe that would hold the flow up, wouldn't it?

 

[Tomswan]

Anyone have a view on different types of filter? Since I am going to have to see this through I may as well be as thorough as I can and think about alternative filters as well as stuff like tiger loops.

Question with regard to tiger loops: they are quite big, so can they be fixed higher up on the boiler room wall and be fed on the supply side using a Flexi-hose attached to the incoming coper pipe?

Even if I get someone in to do it - which I almost certainly would - I would like to be informed first, so I cannot be fed a load of bull.

 

[Tomswan]

This is for information, in case anyone ever gets the same thing happen to them. I took off the new nozzle, and took out the strainer from the new pump, and this is what they looked like:

That looks like algae to my untrained eye. It was so impacted on the pump strainer I had to shift it with a thumbnail. The new pump only went in two or three weeks ago and the new nozzle only two days ago.

So I need an additive that kills algae I guess.