Oil Boiler Goes Bang!

[Boilerman2]

A new top cover is about £40 - a good strip down of the burner check of all ignition parts to ensure an immediate and strong spark across the electrodes

Most oil engineers with any experience will know that although rare, this kind of thing can happen from time to time but the boiler is nearly always repairable !! the water jacket will be fine - it is made of 4mm steel

I've seen at least 10 boilers over the years where this kind of thing has happened - it was even more common with the old Wallflame Burners!!

 

[DeltaT2]

With the greatest respect Boilerman2, I don't think the customer will be too happy with retaining the boiler, but hey who knows??!!

If I recall correctly; it was on a post- purge type boiler with a balanced or low level flue, The Myson Velaire Vitesse for example? I seam to recall one that had it's baffles blown to f.ck!!

 

[DeltaT2]

I'd be interested to know what effect low voltage would have on a solonoid?

 

[snb]

Low voltage has little effect or no effect on the solonoid.

If the voltage is low all that will happen is that the motor will either spin too slowly or not start to spin in the first place.

The effect of the motor spinning too slowly can cause the burner not to burn as intended and leave some unburnt fuel in the exchanger and often a bit of smoke if you happen to notice it. Upon re ignition this is what is likely to have exploded.

I would personnaly repair this boiler and at worst fit a complete new burner unit.

If there is a problem with low voltage you wouldn't want this to happen with most new condensing oil boilers as the damage would be far greater when it damages the secondary exchangers!!

 

[xr4x4]

Would of thought it would been down to the fan pushing less air through the chamber, therefore a stronger fuel, to air mix.

 

[Boilerman2]

On some burners very low voltage can cause the burner motor to turn very slowly and the soldenoid valve to allow oil to drip into the combustion space - this only effects certain burner/Control box combinations

THe Thermecon boiler involved in this incident does not have any post purge function so on this occasion this is not the cause as I have said a few times the fault is without doubt an Ignition problem

This boiler will be fine once repaired I don't see why everyone is so over-excited by what was a fairly minor delayed igntion incident!!

 

[DeltaT2]

But with a low voltage & reduced ampage would there be enought to lift a solenoid? Still think low voltage is sh.te!!

 

[oilhead]

Any control box fitted , if it encounters low voltage, will shut down and close solenoid. From memory, a satronic will operate down to 210volt I believe. To cause an explosion that buckles the top like this indicates that there must have been some lying oil in the combustion chamber, probably from a leaking solenoid. Delayed ignition would have made a noise, but the flue would have absorbed the impact of such a small explosion.The internals of the boiler ( baffles) are not fixed, so will just bounce. It is doubtful if the water jacket will have been damaged.
A faulty solenoid could happen on a new boiler. Properly explained to the customer should allay his fears, but to be doubly sure, fitting an electric solenoid valve as safety, powered through the boiler thermostat, should allay his fears. Much cheaper than a new boiler.

 

[leakydave]

Just an update...

Replaced both top plates and oil solenoid. Boiler still erratic. Even with maximum air I cannot get the CO2 reading low enough.

Suspect fan motor is not running at full speed [that's what manufacturer reckons anyway].

... so new burner ordered for customer peace of mind.