Heating oil level - how low can I let it go?!

[stu550]

Boiler is a Worcester Camray External Boiler. The Riello Burner RD3 sits in the bottom of the boiler with the oil pipe into the side of it.

The oil tank sits a few inches higher than the boiler but is not raised up any more.

Am I right in saying it is gravity fed only?

I presume, the question I need to know is what height is the oil actually drawn into the burner?

thanks.

 

[Terrywookfit]

It will run until the oil drops below the tank outlet.
WTF would you run it so low ?

 

[stu550]

Thanks, wasn't sure whether it would be as low as that given the marginal height difference. I have never run it that low so wanted to know.

Not saying I am going to run it right down but it is good to know as I always run on the side of caution... but also prefer to buy as much oil as I can infrequently if possible...

 

[oilboffin]

If I was you I wouldn't let it run down more than 8inches above the out let if you do there is a chance that dirt and water can be pulled into the pipe and jigger the oil pump and cost you a lot of money.Bob

 

[durhamplumber]

let it run out completely!

 

[garyo]

Ignorant on this but isn't that why there are filter bowls on these?

I thought the pumps provided a marginal degree of suction meaning that the tank base can be a foot lower that the pump and still function?

 

[oilboffin]

A filter will not stop water but don't take my word for it try it and when you've paid an engineer for a new oil pump reflect on your actions.Bob

 

[garyo]

Cheer Oilboffin... I'll be sure to chuck some gravel in at the same time to give it a real test!

Humour me some more though - if the water sinks to the bottom of the tank anyway, how does running the tank low make it get sucked up?

As an aside, how often would you recommend that a householder drains the water from the bottom of their tank - is that something that you do a lot to remedy boiler problems?

 

[oilboffin]

Right when oil is sucked out of a tank it creates a flow,now if you have water in the tank say 2 inches that's near the outlet of the tank with this flow believe it or not it can pull little amounts
of water along with it and through the pump and after a while this minuscule amount of water will
cause irreparable damage to the oil pump,but,like I said don't take my word for it.This is why you need to keep your tank clean and free from water.Bob