Riello oil burner playing up

[reb78]

One of our external oil boilers has been playing up. It locked itself out. On checking the central heating system pressure it was low, I topped it up and the boiler struggled a little but fired. Now its locked itself out again. System pressure was fine. Then I noticed the other boiler on that oil line hadnt come on either (different sealed heating system but same oil line). I stink of kerosene but have cleaned all the filters now - they were filthy and I should have done it sooner. I drained about 15-20 litres of mucky horrible fuel through the line to the boiler that first caused the issue, it had water in it too. I drained until it was clean and water free. Got the boiler fired up initially but now its locked out again and wont fire. The flexi pipe to the pump now has a drip on it where the rubber joins the 90 degree union to the oil pump.

I will replace the pipe tomorrow but will the no firing be a case of air in the line as its leaking now?

Its a 2000 era Riello burner on a Grant boiler.

 

[S-Rail]

I’m no pro , but depending on how much crud went through the filters and water , it could well of seized , gunked up the pump .

I had this as sludge / growth had built up over the years and then been sucked through .. managed to strip and clean the pump and worked ok until I had got a new pump . As they rely on the fuel oil as a lubricant , so once crud and water gets to them they get fubar .

And also you say the fuel pipe ( assuming the flexi ) is dripping . It also will draw in air , which can cause problems .

I then upgraded from a standard paper filter to a clear bodied water separator / fuel filter . You’d be surprised how much crud gets down the line

 

[reb78]

Thanks Sam. I wondered the same thing having had a read this evening. I can probably change/clean the filter in the pump but a pump change needs someone with a guage that i dont have to set the pressure i think.

 

[julianf]

If the oil line is long and has gotten air in it, there will be pockets here and there. It's not uncommon for them to lockout periodically for a few days.


Next thing to always check (just because it's simple, not because it's especially relevant here) is that the photosensor is clean.

Next thing is to change the jet. They have a sintered filter on the rear of them and stuff that will make it through the pump fine will block the filter.

There's three bits of info that you need off the old jet to order a new one. The letters (probably EH or, less likley ES unless it's a larger unit) the gallons per hour (I think they're USG, but maybe something like .75 for 23kw unit) and also the angle of the jet. Maybe 80 degrees. But, whatever, just buy the same as what's in it and you don't then have to mess about with pump settings.

 

[minimutly]

Does the feed line go below ground? If so it forms a u tube (obviously), which can fill with all kinds of dead insects, sludge, cack over the years. I had to put a foot pump on one end of mine, you should have sern the crap that eventually shot out of the end.
Those pumps are hardy beasts, they wear out, eventually, if its seized the motor wont be turning, but I would check for a blockage first up.

 

[julianf]

Thanks Sam. I wondered the same thing having had a read this evening. I can probably change/clean the filter in the pump but a pump change needs someone with a guage that i dont have to set the pressure i think.

They're about £12 from bes for a glycerol filled one. Unfilled jump about so much that you can't get a good reading. But the pumps come preset to the most common pressure anyway.

Swapping the pump is some way down the line though. Plenty to check prior to that. And they're about £60, whilst the the jet is more like £6.

 

[S-Rail]

No problem , my pump had no filter as part of it . It’s a stand alone external filter . Mine is a sterling / Bentone .

To be fair , crude by nature but easy to keep going , probably less than £300 in spares in 18 years now .

When I’ve had to fit new pump / service etc my mate comes round for a cup of tea in exchange .

This is the type I have now fitted …https://www.tanksforeverything.co.uk/water-trap-filter-for-heating-oil-p


Water is a killer on the pumps as is sludge .

Also refiring the boiler and not bleeding the air quickly / properly enough can over heat and sieze the pump .

My bottom of by burner is about the same height as the top of my oil tank as it is an through wall mounted boiler , so the pump has to do all the work of purging , no gravity assistance , so a few fires of the burner , bleed , give it a few minutes , then do it again .

 

[Bravheart]

The jets should also have filters on them have you cleaned them?

 

[Onoff]

I recently changed the two bearings on the motor on mine. It had been getting progressively worse with locking out. All sorted now.

 

[reb78]

Thanks for all of the advice here - I am going to pop out this morning and try to get the internal filter, a new oil line and a new nozzle and then take it from there.

When summer arrives, I will empty the oil tank fully and steam clean it. At the same time, I will drain the lines completely and clean them out - the longest run is probably 50m to the furthest boiler from the tank. I doubt anything has been cleaned since it was installed around 2000. I did the filters the year before last but ran out of time to do them this year.

Is there a decent filter/water trap system I could install at the tank where it is easy to drain and change?

This was the crap I drained off last night - this was about the third tub. I didn't stop until I had clear waterless fuel but then the flexi pipe started dripping and the boiler had refused to fire anyway (I stopped trying once I noticed the leak).

 

[armalites]

I took the opportunity to clean my tank a couple of years back. It's amazing how much junk was in the bottom, ours is a 2500L plastic and i reckon there was 2-3 inches of muddy pond water in there. It has stayed clean but I can see the glisten of the odd spot if water in there now. It's time consuming and messy to clean them out, i was fortunate in that I could move it into the yard. I cleaned with a hot/steam pressure washer and loads of detergent and then dried it with compressed air and towels on the end of a broom handle.

Keep an eye out on Facebook, often tanks can be had for pennies or even free, it's useful to have a second if you need to pump yours out.

 

[reb78]

I took the opportunity to clean my tank a couple of years back. It's amazing how much junk was in the bottom, ours is a 2500L plastic and i reckon there was 2-3 inches of muddy pond water in there. It has stayed clean but I can see the glisten of the odd spot if water in there now. It's time consuming and messy to clean them out, i was fortunate in that I could move it into the yard. I cleaned with a hot/steam pressure washer and loads of detergent and then dried it with compressed air and towels on the end of a broom handle.

Keep an eye out on Facebook, often tanks can be had for pennies or even free, it's useful to have a second if you need to pump yours out.

Good advice. Thanks. I have just done my spare tank that is planned for diesel. I have the offer of an old red diesel tank from one of the farms i work with so i will grab that as a spare for kerosene I think!

 

[reb78]

So a few pictoral updates for comment. The nozzle looks fooked.

The flame sensor looks clean though.

Off to get parts now.

Does the electrode position look right or are the ends of those electrodes eroded?

 

[Onoff]

Is the photocell clean?

 

[julianf]

That nozzle filter has visible crud all over the back of it.

I'm not saying that's certainly your problem, but it's not good!

If you power up the unit, out of the exchanger, it will go through a purge cycle and then fire, assuming the photosensor is covered.

Whilst it's firing if you shine a torch at the photosensor it will think it's lit and carry on pumping without going to lockout.

Anyway...

Do you get oil spraying out of the nozzle?

If no, then remove the nozzle and try again. Is there oil spurting out of the tube?

If the answer is then "yes" it's the nozzle.

If no, then it's something else.

You can have the solenoid fail on them or the (I think) reed valve (the oil control mechanism controlled by the control unit) so there's loads of things to check.

Don't worry about the electrodes yet. If there's no oil coming out then they can be sparking for all their worth and you still won't get ignition.

 

[julianf]

Ps.

Dont mess with the electrode position. It's one of the more irritating things to get right and, if it was working before, it's not like they will have moved in secret.

 

[brightspark]

if its sparking properly leave em alone you can run the burner out of the boiler to test it but just aim it out of the door and cover the floor upits like a mini flame thrower thats how i tested and set up my steam cleaner

 

[Stueeee]

When I let the oil run out some years ago it was ages before the three burners settled down without locking out every 20 minutes or so -I put that down to bubbles/air locks in the feed(s) If your pump had seized I would expect it to have blown the fuse rather than lock out. That's what happened on my Ecoflam burner here. I cleaned and lubricated the Danfoss pump and it's still working several years later.

One other time when the burner was locking out, the copper tube from the pump to the jet had become almost completely blocked with crud. Once again cleaning it out seems to have fixed it.

Every time a service engineer arrives to look at the oil fired range and the two boilers here, they are dead keen to sell me a new burner for £££. I have a good set of new consumable spare parts and a more-or-less complete Ecoflam burner/parts donor bought off ebay so I intend to keep mine alive as long as possible.

 

[Onoff]

When my oil has run out I've done two things:

Disconnected the oil pipe at the external fire valve and fired the compressor nozzle up it. Sends a whoosh of compressed air up the pipe back to the tank. Pipe to the left:

I have more success though with "sucking" on the end of the oil pipe with one of those oil suction gun / syringe things.

A few sucks draws the oil through from the tank. I squirt the oil into a jug then chuck it back in the tank through a cloth to filter it.

As always I then bleed at the pump to get any air out whilst the boiler is trying to fire up.

I bleed here. 4mm Allen key I think:

Ref the lockouts, bloody annoying I know. Clean the photo cell of course. Worth checking the solenoid as aforementioned above, the capacitor too. I'd gone through all that a little while ago but it ended up being the bearings. Changing them eventually fixed it. You can see the rust from the old ones.

Get a pressure gauge too. Set mine down to 8bar as per the book.

There's also a little (plastic) pump coupling, part number 3000443 that sits between the pump and motor. That's a bit that wears. The small metal key too is a common wear issue.

Mine really is the Trigger's Broom of oil boilers!

Just can't afford oil now!

 

[reb78]

So...

New nozzle, cleaned the internal filter (it was filthy), I sprayed wd40 around the pump to clean out the crud. New pipe fitted. Bled.

No joy.

The photocell reacts as Julian suggests so that works - i.e. shine a light and it keeps purging. Take the light away and the electrodes fire.

There is nothing coming out of the nozzle and nothing coming out with the (new) nozzle removed.

What next. I am a bit stumped. I have holiday makers jn this cottage! Lucky its not cold and they are lovely!