six weeks, six visits, still no working boiler

[Burnerman]

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.

With diesel fuel injection there are other factors to consider - even makes of fuel can make a difference, I’ve found. I run my 2.0 litre Yeti on Shell V max diesel and the smell is very faint, but that changes when its administering Ad Blue - and there’s much more vapour present.
Anyway, with a modern common rail diesel, a fuel filter change at 20k is desirable. If you do it yourself you can also see if there’s any water present.
With my own boilers I can smell if all is ok, to some degree anyway - and there is definitely no visible smoke.
John

 

[Burnerman]

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.

Just for more info ( I hear you yawn) your boiler will have a fume sampling point just at the flue outlet....often just a bolt.
Ideally you first take a fume sample with a smoke pump, and pass that gas through a filter paper to see any carbon deposits. If all is ok there ( excess carbon gooses a FGA) then in goes the FGA probe and its switched on. After a few seconds it starts to analyse the CO2 content, and by adjusting the air door on the burner very slowly you can see the readings slowly change.....great fun!
John

 

[sxturbo]

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.

I'll post up some pics Monday of a clogged fuel filter that failed, it then stopped filtering as the filter medium degraded and collapsed.

 

[Harry Bloomfield]

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?

It is what gets through the filters and ends up sticking around the injector nozzles and other parts of the fuel system, which alters the spray pattern, which is the problem - sticky deposits. I have used them a couple of times in the past and noticed a little difference in the MOT smoke test after the first cleanup, but none since. It's basically just a solvent, ATF.

The quick way to clear injectors, is to simply add the cleaner to your fuel filter, give it a short run for a few seconds, enough to get the cleaner into the injectors - then leave it to soak over night.

 

[Tomswan]

It is what gets through the filters and ends up sticking around the injector nozzles and other parts of the fuel system, which alters the spray pattern, which is the problem - sticky deposits. I have used them a couple of times in the past and noticed a little difference in the MOT smoke test after the first cleanup, but none since. It's basically just a solvent, ATF.

The quick way to clear injectors, is to simply add the cleaner to your fuel filter, give it a short run for a few seconds, enough to get the cleaner into the injectors - then leave it to soak over night.

Interesting, thanks.

 

[Tomswan]

Right, well it has cut out again.

Gosh.

However, this time I am hoping it is an air lock. Like I said, after he fitted the new filter there was an accumulation of kerosene in the plastic container I put down to catch any spills. I emptied that earlier on and when I went back there was a small amount in there.

Raining at present, so not going out to try to work in that. However, tomorrow temperature back up to seasonal average and hopefully won't be raining so I can have a look.

If air lock pretty simple to deal with. If not, then back to drawing board I guess.

In any event, I am going to change filter for smallest particle filtration, which I think is 10 microns.

 

[Burnerman]

Is your boiler gravity fed with kero, Tom or does it pull the fuel upwards through a tiger loop deaereator maybe?
John

 

[Tomswan]

Is your boiler gravity fed with kero, Tom or does it pull the fuel upwards through a tiger loop deaereator maybe?
John

Gravity fed with kero. . Storage tank is well above height of burner some distance away. No tiger loop.

When I checked this morning the filter housing as well as nearby isolation valve (supply side of filter) were wet with kerosene, but then I did not know if that was a result of handling when he put new filter in. Now I know there is a small leak, so presumably if there is kerosene coming out there must be air going in.

 

[Tomswan]

It is tempting to blame the chap who came out, but he was working outside in freezing conditions on Friday. He may have pinched the rubber seal when tightening up after refitting the bowl.

I certainly hope so.

I guess a tiger loop would solve any problems of air getting in, but I would rather be sure there are no leaks in the first place.

 

[Tomswan]

I'm not sure whether to be angry, relieved or amused. At this point I reckon I am halfway to being able to maintain the system on my own, so the fact that it has cut out again affords me an opportunity to solve the problem on my own.

I am not getting any of the previous people back again, not now. Unfortunately, there is no way no know whether anyone new will be any better. So that leaves me.

I have tried to resist overreacting, and I do not think I am being unfair.

 

[Burnerman]

A gravity system is simple enough and shouldn’t require a tiger loop unless air is being ingested somewhere. A smear of grease around any suspect joints should help there.
Unfortunately it looks like its filter check again but if it was mine I’d pop the supply pipe to the burner (flexy hose) and draw off a litre or so. If the flow is good then any upstream filters are fine.
I have found on one occasion on a long run pipe (15mm) that there were considerable black deposits on the long, near horizontal runs but so long as the flow at the boiler end is good then that’s ok too.
I’m not a heating engineer by the way, just someone like you who needs to know about things!
John

 

[Tomswan]

Here's another potentially relevant bit of new information: Since the burner cut out no new kerosene seems to have leaked out at the isolation valve or filter housing.

So is this a reasonable conjecture: when the pump works to draw oil through it draws air in and forces kerosene out where a small gap forms , but when the pump is off the leak is sealed again? Ie, air is sucked in only during operation?

 

[Tomswan]

A gravity system is simple enough and shouldn’t require a tiger loop unless air is being ingested somewhere. A smear of grease around any suspect joints should help there.
Unfortunately it looks like its filter check again but if it was mine I’d pop the supply pipe to the burner (flexy hose) and draw off a litre or so. If the flow is good then any upstream filters are fine.
I have found on one occasion on a long run pipe (15mm) that there were considerable black deposits on the long, near horizontal runs but so long as the flow at the boiler end is good then that’s ok too.
I’m not a heating engineer by the way, just someone like you who needs to know about things!
John

Thanks. I guess if it is the filter again then that is good news - it will mean there is crap in the supply line still coming through. A limited number of filter swaps ought to take care of that.

I suppose one other possibility would be that some particulate element has been crystallising out of the body of oil in the tank and accumulating near the bottom outlet. Too fine to be caught by the nylon filter at the tank outlet but course enough to be caught by the paper element near the boiler.
Again, repeated filter swaps should deal with that.

I must get onto the additives in any case, since presumably those will break down accumulated deposits in the supply line and flush them through. As long as they don't work to compromise the supply line.

 

[Burnerman]

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

 

[Tomswan]

A gravity system is simple enough and shouldn’t require a tiger loop unless air is being ingested somewhere. A smear of grease around any suspect joints should help there.
Unfortunately it looks like its filter check again but if it was mine I’d pop the supply pipe to the burner (flexy hose) and draw off a litre or so. If the flow is good then any upstream filters are fine.
I have found on one occasion on a long run pipe (15mm) that there were considerable black deposits on the long, near horizontal runs but so long as the flow at the boiler end is good then that’s ok too.
I’m not a heating engineer by the way, just someone like you who needs to know about things!
John

I already know the filter at the tank is ok because I checked. The only other filter is near the boiler, the one that was changed.