B11 burner problem

[exon16m]

My boiler keeps tripping out.

Attempts so far:

I have just cleaned and serviced the main parts inc replace nozzle as per manual.

I have found the problem to the tripping out oil is not getting to the nozzle reliably. Only way to get the boil to fire up is to loosen the connection to the burner to release the pressure in the line and tighten as soon as the valve on the oil pump opens and the boiler will fire perfectly.

so in my mind there are two possible culprits:

1) check valve - I did look at it in the service and holes are clear. do they become sticky? or eventually fail? I cant find a diagram of the internals but I think its just a sprung ball bearing based valve

2) oil pump pressure not quite high enough to open check valve (nothing here has been touched in terms of pressure regulation valves and don't have the kit to check air ratios after so not intending to go alone on this.)

So my question:

Is it worth changing the check valve or is it unlikely to have failed and more likely to be down to the pump pressure or early pump failure ?

 

[Agile]

Air in supply line or leaking in?

Sounds like a DIY service!

If so then how do you confirm that the pressure is correctly set and the combustion setting are correct?

Tony

 

[exon16m]

Air in supply line or leaking in?

Sounds like a DIY service!

If so then how do you confirm that the pressure is correctly set and the combustion setting are correct?

Tony

As said, not touched any of the oil pressure settings or air settings (nor plan to).

If the settings were all correct before should they have changed?

 

[Agile]

I have just cleaned and serviced the main parts inc replace nozzle as per manual.

I would expect the manual also says to check the oil pressure and the combustion aspects with a gas analyser!

Particularly after changing the nozzle.

I am not an expert on oil boilers but would expect that fine material in the oil will wear the nozzle larger over time.

A larger nozzle will alter the combustion and require the air settings to be adjusted at a service if the nozzle is not replaced ( which would be normal at a service ) and whenever a new one is fitted the parameters should always be checked. Otherwise the benefits of the new nozzle can be lost.

All settings can drift and need checking at least anually. With the cost of oil any small saving through correct combustion becomes quite significant.

Tony

 

[Boilerman2]

When you try and start the boiler - (without loosening anything) does the flame appear during the pre-purge -before the oil valve opens?? if so this is why the burner then runs to Lockout -if this is happening you need to replace the solenoid valve Stem (the part you have described) it simply unscrews from the pump and the new is fitted in reverse order, this will not effect the fuel pressure setting.
But as Tony has said it is a good idea to get Oil (& Gas for that matter!) boilers serviced regularly so that a competent engineer can accurately reset the Combustion values

 

[Murf520970]

boilerman can you explain why the boilers firing on prepurge please , been doing oil boilers for a few weeks & thats a new one to me matey , whats happening & why, why is the solenoid stem at fault & what is wrong with the stem , no one mentioned anything like this while i was training

 

[Burnerman]

New to me too
I'm all ears (said the elephant)
John

 

[oilhead]

The boiler will fire on prepurge on a B11 if it is satronic box. The spark starts upon power up, and if the solenoid valve is passing, then it will light the fuel, but go to lock out for premature ignition.
Check the solenoid valve for current, the box may be faulty. Also, once lit, check the transformer feed for current. If the box holds it on, then you will burn out your transformer. I bet they never covered that on your course.

 

[Agile]

I wanted to ask that too but was frightened of being laughed at !

Surely the spark should not be timed to be on until just before the oil supply is turned on ???

Tony

 

[Burnerman]

Depends on the make of the burner Tony....some have the ignition spark during the purge (where you can happily see it), others only spark when the oil is switched on to flow - where singed eyebrows can result
I thought the B11 was the former type, but this symptom is not one I've come across before....sure, valves stick open and flood the combustion chamber but I didn't know that some controllers would allow ignition just to shut it off again because it was too soon!
John

 

[exon16m]

It has a bentone box.

It appears to go like this when working. Non tecnical :

Air blower and oil pump prime 5 sec
Click open oil valve
With in a second catches

Now broken verson sometimes does not restart as oil does not over come check valve. If I loosen the line allow a little leakage on a tissue a few ml and then shut just after the click when the oil valve opens and it will always fire.

In my mind I have put this down to a sharp pressure rise being enough to open the check valve. But was also woundering if a dropped pump pressure was a better fit to the problem

 

[Murf520970]

The boiler will fire on prepurge on a B11 if it is satronic box. The spark starts upon power up, and if the solenoid valve is passing, then it will light the fuel, but go to lock out for premature ignition.
Check the solenoid valve for current, the box may be faulty. Also, once lit, check the transformer feed for current. If the box holds it on, then you will burn out your transformer. I bet they never covered that on your course.

apologies to the poster for asking questions
do we check for current using a clamp on type meter or standard test meter , & no this stuff never came up , im here to learn of you experienced oil heads

 

[Burnerman]

To my completely untrained eye, I'd be interested to see what the pump pressure was set at!
I'd jump at working with a time served oil man - all I know has been found by trial and error.....no manuals, nowt
John

 

[Agile]

I rather think thats a better way ( although longer ) but it does not start with any preconceived ideas!

Reminds me of my trainee whom I had left to point out the faults in an installation to the installer.

He told the plumber the pump shaft should not be at a 45 degree angle. The plumber snapped back that he had installed hundreds like that.

Trainee replied " then you have fited hundreds wrongly then "

Tony

 

[Danoil]

It has a bentone box.

It appears to go like this when working. Non tecnical :

Air blower and oil pump prime 5 sec
Click open oil valve
With in a second catches

Now broken verson sometimes does not restart as oil does not over come check valve. If I loosen the line allow a little leakage on a tissue a few ml and then shut just after the click when the oil valve opens and it will always fire.

In my mind I have put this down to a sharp pressure rise being enough to open the check valve. But was also woundering if a dropped pump pressure was a better fit to the problem

Sounds like delayed ignition, are the electrodes set correctly? Check the pump pressure is at stated pressure, and check combustion with your FGA(too much air could cause this)

The oil does not have to "over come" anything. Pump pressurises oil, coil energises and lifts solenoid, oil is released. What do you consider to be the 'check valve'?