Servicing oil burner

JMSE

Lads and femmes...

My burner is a Bentone Sterling 40 ST108 (year 2000).
Ive never had a plumber service it in 9 years since I had it fitted because I can handle cleaning the injector well the outer parts of it anyway, and Ive cleaned the boiler out from year to year.

But its started to missfire lately, it burns and then drops out and ignites again. Any tips? Theres no visible air cleaner. On the front of unit behind a cover theres an adjustable dial but nobody's been near that ever.

The oil tank is brand new, theres 2 filters in the line.
Should add, there 14mtrs between tank and burner, height of tank is only about 1 ft off the ground.
Any tips????

Micky Dolenz

You will have to replace injector, they need to be replaced evert year as the filters that are built in to them get blocked.

If is also important to take a reading of pump oil pressure to ensure you aren't burning more oil than you should be.

JMSE

micky do you know where service stuff like that can be bought, worth a go if its cheap

items

9 years is good going without any major issues. If you've not changed nozzle at all in 9 years that could be your problem. For an Oil burner to fire correctly the consistency and angle of spray of Oil from nozzle has to be as close to perfect, if you've not changed nozzle I'd say its fairly wore out, friction will eventually wear down nozzle opening which effects pressure along with angle of spray.

You might have a few things going wrong at mo which causes burner to run intermittent, to be honest would do no harm to have boiler serviced by a proper service person. Proper chaps test combustion with probe in flue and set boiler nozzle / pressure and air for maximum efficiency.

You might save the cost of service with less heating bills depending on how efficient boiler is currently.

JMSE

items wrote: »

9 years is good going without any major issues. If you've not changed nozzle at all in 9 years that could be your problem. For an Oil burner to fire correctly the consistency and angle of spray of Oil from nozzle has to be as close to perfect, if you've not changed nozzle I'd say its fairly wore out, friction will eventually wear down nozzle opening which effects pressure along with angle of spray.

You might have a few things going wrong at mo which causes burner to run intermittent, to be honest would do no harm to have boiler serviced by a proper service person. Proper chaps test combustion with probe in flue and set boiler nozzle / pressure and air for maximum efficiency.

You might save the cost of service with less heating bills depending on how efficient boiler is currently.

I agree, will do, thanks.

JohnnieK

This could also mean that the fuel pump has become faulty. The pressure should be checked on the pump, If it is fluctuating aggressively the pump will have to be replaced.

The nozzle should definitely be changed every year. And at the most two years.

Stegliano

Hi Guys

Can I raise a query in this thread also about a Bentone Sterling40 108E - 3 years old - ? It packed in last night!

The boiler had a lot of soot - I had cleaned it last Summer - and there was quite a build up of 'sooty oily' matter on the nozzle and electrodes. The flue gases have always been clear. I have cleaned the boiler, nozzle and electrodes. It is producing a good oil spray but there appears to be no spark! I have checked the electrode gap seems to be correct.

Any thoughts??

JohnnieK

It could be the ignition transformer or a faulty HT lead.

Fr Dougal

Hi Folks,
I have the Bentone Sterling ST108 burner.

Four days ago I was very very low on oil, about an inch over the outlet on the tank and I got a fill of Kerosene. Heating has worked fine for the last four days and just stopped working this morning. It has been working fine up to now.

It doesn't seem to be going through the ignition cycle.
The error light is on, when I press the light, it goes off and a slight hum comes from the unit for about a minute or less, then the light comes back on.

Any ideas what I can check?

The unit was installed about 5 years ago but hasn't been sserviced since.

The tank is about 25 metres away and about 2 foot higher than the burner. Two filters, one at the tank and one at the burner.

Could it need bleeding and if so, where is the bleed screw? I used to have to bleed the old one. (Although I guess if it's not going through the ignition cycle then it is probably not an oil feed fault???)

Thanks in advance.

shane0007

Fr Dougal wrote: »

It doesn't seem to be going through the ignition cycle.
The error light is on, when I press the light, it goes off and a slight hum comes from the unit for about a minute or less, then the light comes back on.

The capacitor is faulty. This is the white cylinder like component located on the bottom front left of the burner. Replace this with the same type, i.e. 4.0uF, 4.5uF or 5.0uF. This will be marked clearly on the capacitor.

DGOBS

Quick check would be open the main burner cover (single allen nut facing you) to access the fan, with power off, rotate the fan to see in it free moving, if not either a faulty motor or pump, the latter being the more likely.

If free moving, as Shane suggests it's the capacitor (silver body, not white on the bentone)
you can check by giving the fan or shaft a quick flick when the burner is 'humming' to kick start the motor (be very very careful not to trap your fingers!!! it will start spinning fast straight away) if it starts then fires, go get a new capacitor, you can check it electrically with a multimeter that read capacitance either.

Parts supplier is not far from you either, Precision heat in Blanchardstown are the agents

Fr Dougal

Cheers guys, my mate, who is a plumber, dropped down yesterday for a quick look.

He stuck a pressure gauge on and is not getting any oil pressure. He was wearing his Sunday best so was not going to work on it yesterday but he is gonna drop down tonight to put it on the bench and have a look.

He pulled the pump out anc confirmed that there is a spark.

However, the motor on th eleft side is getting quite hot, even though it doesn't seem to be turning. I will show him your replies.

Any idea were I could download a workshop manual?

Cheers folks.

Fr Dougal

shane0007 wrote: »

The capacitor is faulty.

DGOBS wrote: »

If free moving, as Shane suggests it's the capacitor (silver body, not white on the bentone)
......

Parts supplier is not far from you either, Precision heat in Blanchardstown are the agents

Top of the class guys. Replaced the capacitor on Monday and she fired up immediately and worked fine since.

Got the part in precision Heat as recommended, guy was very helpful and agreed it was the first thing to do. Also replaced the jet, cleaned electrodes and replaced the firevalve on the inlet line as it looked ancient and all crudded up.

Gonna take the top off the burner on Saturday and clean out any soot.

Thanks again folks.

Fr Dougal

More problems.

I have oil flow, stuck a guage on and the pressure is showing 8bar.

Fan will run for a bit then the light comes on. No spark, cleaned the electrodes. Checked the photocell and it is clean.

Any ideas?

EDIT: Looks like the solenoid or solenoid valve not working, would this stop it from sparking?

EDIT2: Solenoid valve seems to be working, jet is spraying a mist of oil but no spark.

DGOBS

Spark generator on LHS of burner faulty, also check electrode leads are in good nick, and electrodes ceramic is not cracked.

Fr Dougal

Checked the electrode leads and they seem okay, no marks and no perishing. There is a small chip in the ceramic at top of electrode.

EDIT: Would a spark geenrator and new electrodes/leads be expensive?

DGOBS

Next would be change the spark generator