six weeks, six visits, still no working boiler

[Tomswan]

A clogged filter won't stop the oil flow.

But it will reduce it, and it will let particles pass that should have been filters out

Yes. I know for a fact that it doesn't stop the flow. In an uncertain world that fact is something I can hang on to, for I have seen it with my own eyes.

However, there is this - and it confirms what you just posted - the old pump had seized and was swapped out as part of the repair process. So I dare say that the clogged filter had been causing it to work too hard and that had led to its demise, taking the motor with it.

Had the filter been changed on an annual basis I dare say the original pump and motor would still be in the burner and none of this would have happened.

 

[Mottie]

A clogged filter won't stop the oil flow.

But it will reduce it, and it will let particles pass that should have been filters out

All that will pass through a filter is the medium it is supposed to filter - air or fuel. Only exception will be the bypass system in an engine oil filter on the basis that even unfiltered oil is better for the engine than no oil. If an oil or air filter lets particles pass that should have been filtered out, it’s not a filter! It will gradually reduce the flow as it becomes clogged until it reaches the point of being completely blocked. There will be some obvious sign of this such as bad smells and/or reduced performance of the unit it is protecting.

 

[Tomswan]

All that will pass through a filter is the medium it is supposed to filter - air or fuel. Only exception will be the bypass system is an engine oil filter on the basis that even unfiltered oil is better for the engine than no oil. If an oil or air filter lets particles pass that should have been filtered out, it’s not a filter! It will reduce the flow as it becomes clogged until it reaches the point of being completely blocked. There will be some obvious sign of this such as reduced performance of the unit it is protecting.

Well, I don't think there is any cause for disagreement, because the obvious sign was the burner lockout after the nozzle filter became clogged.

It must be the case that a filter reaches a saturation point where it loses its ability to filter out impurities from the medium in which it is immersed. Hence the need to change it on a regular basis.

 

[Harry Bloomfield]

A clogged filter won't stop the oil flow.

But it will reduce it, and it will let particles pass that should have been filters out

It depends whether it has a bypass. I once got stuck at the Tan Hill, in a Celica, where the fuel filter became blocked. Performance gradually deteriorated as I climbed up the Pennines, it rapidly got much worse, then refused to even start.

 

[Mottie]

Well, I don't think there is any cause for disagreement, because the obvious sign was the burner lockout after the nozzle filter became clogged.

It must be the case that a filter reaches a saturation point where it loses its ability to filter out impurities from the medium in which it is immersed. Hence the need to change it on a regular basis.

Main thing is....it’s working and that’s all that matters.

 

[Tomswan]

It depends whether it has a bypass. I once got stuck at the Tan Hill, in a Celica, where the fuel filter became blocked. Performance gradually deteriorated as I climbed up the Pennines, it rapidly got much worse, then refused to even start.

Well, perhaps there is a period after a filter loses its capacity to perform its function and before it becomes completely blocked. So a 'dirty' filter will reach a point where it allows the medium to flow (perhaps at a reduced rate) but no longer takes out the impurities it was designed to remove. So, in my case, those impurities would continue downstream until they reached another filter which could take them out - the nozzle filter.

I wonder how many old diesel motors are chuntering along the roads because the fuel filters are compromised but not blocked to the point where the diesel can't get through them.

 

[Tomswan]

Main thing is....it’s working and that’s all that matters.

Not quite (although I am mightily relieved) - I want to continue with this until I have a thorough understanding of it, so that when it happens again I am not so helplessly dependent.

 

[Burnerman]

Keep a couple of spare filters in stock, Tom.
Regarding the nozzle, the sintered metal filter is unscrewable and can be cleaned with carburettor cleaner and compressed air if necessary to get you going again.
The nozzle can also be dismantled but it’s not recommended due to the very fine clearances within.
John

 

[Tomswan]

Well now, here's a thought: every so often I add stuff to my tank to clean off the injectors, or I use premium diesel to do that same thing, and then shove it into fourth and ramp it down the motorway.

Suppose the reason for needing to do that is not changing the fuel filter regularly enough. After all, if the inline filter was doing its job, why would the injectors get crapped up?

Is there a whole industry that has arisen because someone realised nobody was changing the fuel filters at regular intervals?

Come to think of it, how many high pressure pumps get knackered because the fuel filters are clogged?

How many sky high emissions are there because the air/fuel mix has been altered because saturated filters have not been changed?

 

[Tomswan]

Keep a couple of spare filters in stock, Tom.
Regarding the nozzle, the sintered metal filter is unscrewable and can be cleaned with carburettor cleaner and compressed air if necessary to get you going again.
The nozzle can also be dismantled but it’s not recommended due to the very fine clearances within.
John

Spare nozzle already ordered, and tomorrow morning I am back down the plumbers merchants to get another couple of filters.
I am also going to get another burner (same one so I can straight swap if need be) and rig up a supply on a bench, and then play with it until I can strip the bugger down and reassemble it blindfolded.

I've already got another used spare nozzle so I will clean it off as you advise - thanks - and keep it as a back up.

I am looking at changing the in line filter, though, for a bio filter. I have seen spin on filters which are good for kerosene and bio fuel. I figure that if bio fuel is being added to kerosene I maybe need a filter that will work for both. I am currently using a filter system that pre-dates the mania for fouling perfectly good mineral oil with vegetables (if I have understood it right).

I am also tempted by the tiger loops, mostly for the pre-heat function you get as a byproduct of pump friction. Or I wondered whether running two in line filters on the same fuel line would add an extra layer of protection. Although I also wonder whether that would put additional strain on the pump for virtually no reward.

 

[Burnerman]

I have a spare burner for each of my two properties.....one is an ancient Inter 10 and the other a B9A from my Worcester heatslave.
I’ve a small plastic tank on my garage wall for the kero, it has a valve and a length of polythene tube with a 1/4 BSP female fitting on the end. I couple the contraption up, remove the air bubbles and get cracking.
For experimenting you will need a twenty quid pressure gauge as a new pump is often set much too high at 150 psi - typical working pressures are 100 to 120 and often the requirements are on a label inside the boiler.
A flying wire supplies mains voltage.
When I’m testing mine I withdraw the photocell and hold it in my hand so its dark, and once the burner lights up I let the photocell see light which keeps the thing burning.
Just for interest, here’s a typical start up sequence:
Motor and fan starts up, the ignition is sparking here, purging fresh air for around 8 sec.
A solenoid on the oil pump switches the oil on, and burning commences.
A couple of sec after this, the ignition spark stops and burning continues.
Unfortunately you will need a flue gas analyser to set up the air mixture once the burner is in the boiler so don’t adjust the air inlet door at all.
Pleased you seem sorted for now!
John

 

[Tomswan]

I have a spare burner for each of my two properties.....one is an ancient Inter 10 and the other a B9A from my Worcester heatslave.
I’ve a small plastic tank on my garage wall for the kero, it has a valve and a length of polythene tube with a 1/4 BSP female fitting on the end. I couple the contraption up, remove the air bubbles and get cracking.
For experimenting you will need a twenty quid pressure gauge as a new pump is often set much too high at 150 psi - typical working pressures are 100 to 120 and often the requirements are on a label inside the boiler.
A flying wire supplies mains voltage.
When I’m testing mine I withdraw the photocell and hold it in my hand so its dark, and once the burner lights up I let the photocell see light which keeps the thing burning.
Just for interest, here’s a typical start up sequence:
Motor and fan starts up, the ignition is sparking here, purging fresh air for around 8 sec.
A solenoid on the oil pump switches the oil on, and burning commences.
A couple of sec after this, the ignition spark stops and burning continues.
Unfortunately you will need a flue gas analyser to set up the air mixture once the burner is in the boiler so don’t adjust the air inlet door at all.
Pleased you seem sorted for now!
John

Thanks very much for that, John.
Yes, the gas analyser is a nuisance. The pressure gauge is no problem, but I don't really want to fork out for an analyser, and then for an annual re-calibration service - on the off-chance I will need it. Would be tempting, though, if one came up secondhand. Maybe there is a model you can calibrate yourself.

 

[Burnerman]

Sadly I don’t think that is the case.....I have a second hand Kane analyser but it needs a new oxygen sensor every 18 months, and that plus it’s calibration is well over the ton every time. In fact mine isn’t working just now so I take great care not to fiddle with any air doors the burner has. I’ll send it away soon though.
John

 

[Tomswan]

I realise this is going off at a tangent, somewhat, but I am fascinated by possible parallels between the boiler set up and a motor diesel injection system.

I have a hunch, now, that if you stand behind your diesel vehicle while it is running at idle, and you get a smell from the exhaust which shouldn't be there, then you would ultimately trace it back to a fuel filter that needs changing.

As a result of your kind advice I am going to get the fuel filter on my car changed next week, and I will not be using a cheap aftermarket filter, either.

It will be very interesting to see if the faint off smell I get disappears as a result.

 

[Tomswan]

Sadly I don’t think that is the case.....I have a second hand Kane analyser but it needs a new oxygen sensor every 18 months, and that plus it’s calibration is well over the ton every time. In fact mine isn’t working just now so I take great care not to fiddle with any air doors the burner has. I’ll send it away soon though.
John

Ah, pity. Sounds like they have nobbled the enterprising DIYer on that one (maybe with good reason though).

I suppose one really shouldn't cut corners with this, so an alternative for me will be to get someone in to do a gas analysis after I have done any work.