trainee plumber needs help.

[Dava811]

So I got a call from a friend this afternoon to see it I cud go over to his house to fix his boiler which I have done a few times, and here's the problem.

It's an rdb oil burner, he ran out of oil, he topped it up with 300 litres, so I bled it, he has a tiger loop which was empty of oil. The level of the oil in the tank is about even with the level of the burner. I got the tiger loop filled again about a 1/4 the way, not sure how much oil is meant to be in it.

Eventually I got it firing up but the flame seems to die off after a few seconds and cuts out then ignites and that cycle continues over and over again.


The flame slowly dies off as if the oil stops flowing to the nozzle. the burner has been bled properly.

please help me out, I'm lost.

 

[Nostrum]

Hi,

There should only be about 10mm of oil in the tiger loop so that is fine. When you get it running are you seeing a stream of air bubbles entering the tiger loop?

Do you have an oil pressure gauge?

The oil level in the tank is irrelevant as its on a tiger loop so thats no problem. Where about's are you, is it sub zero temperatures? You may have water in the oil line which has frozen, but that would probably cause the tiger loop to drain so unlikely to be the case. You could also check the filter which is on the riello burner pump housing (is it an RDB burner/what boiler is it?) as you may have dragged some muck through the oil line and blocked the filter.

Sam

 

[Dava811]

Yes mate there is air bubbles entering the tiger loop, there is a gauge on the right hand side of the burner between 0-9, its currently set at 5. I cleaned the filter on the burner, I'm in Belfast and it is quite mild about 6 c when I take out the bleed screw there is not a steady flow of oil coming out..

 

[Nostrum]

The pump on the boiler should pull that through and the tiger loop should sort out the air issues without the boiler going on and off. What boiler is it?

When it clicks off, is there still oil in the tiger loop?

The gauge on the burner is the air mixture setting, don't touch!

Has anything else been touched, have you cracked any joints etc?

You may not get oil gushing out the bleed as its on a tiger loop rather than gravity fed, so not nearly as much pressure behind it, there should be something there though, have you've checked the fire valve is open, I would have thought it would be fine if the tiger loop is full.

 

[Nostrum]

Also forgot to say, once its running, don't bleed pump, it can draw air in, just leave it to the tiger loop to sort out.

 

[Dava811]

Yes there is still oil in the tiger loop tho it drops a bit, I disconnected the tiger loop and the little filter before it on the oil line, but thats wen the loop was empty, I've since got it filled, there is a little black rubber button on the fire valve I may have arsed about with but not sure if thats relevant. Wen I take the burner out of the boiler and fire it up it does the same, fire up then slowly the flame dies out, I think the boiler is a turoc? Very similar to warmflow.

 

[Nostrum]

Its sounding like its starved of oil, if the tiger loop is still full then it has to be after that doesn't it? Have you definitely removed the side of the oil pump (4 allen key bolts) and checked the plastic gauze type filter and washed it out in oil? Did you make sure the rubber O ring was seated 100% when you refitted it?

Whip the fire valve out and make sure its open and physically blow through it. Check all the connections you have touched and make sure they are up tight, When the oil pumps going its pulling about 120psi so it will pull air through like there's no tomorrow.

 

[Dava811]

Would it be worth. Trying a new nozzle ? I cleaned the filter in water but dried it all off..

I'm not sure how to "whip the fire valve out" sorry, could u advise me thanks.

 

[Nostrum]

The nozzle wont cause the burner to click out, it'll just create a poor flame pattern and eventually cause sooting and lower efficiencies. Water and oil don't mix! In future always grab some oil out of the tank, or use something like WD40 so that it burns off quickly when it goes through the pump. The fire vale should just be on the oil line with compression or flared fittings, just isolate the oil line, then undo the nuts and blow through it being careful with the phial pipe (small copper pipe off the top of it)

May be worth getting a local oil engineer in if the basics don't fix, maybe ask if you can sit and watch what he does for future reference.

Sorry, can't be much more help than that without seeing it for myself.

Sam

 

[Best]

Too many things to check, for someone to go over them all. Only things I would say is entire oil line, oil hoses & all, needs to be checked for leaks, water & dirt.
The oil pumps on those RDB burners are scrap, so I am never surprised to find them misfiring.
Be careful the oil tank hasn't water in it or if the tank has a tube sight gauge, that it isn't letting rain water into oil line.
The fire valve black button is only if valve trips off if its sensor gets heat.
You may still have to bleed oil pump using the large stem on pump despite the tigerloop deairator.
If the tiger loop keeps bubbling, you may have a leak in oil line or oil hose somewhere.
The photocell, if dirty, will make burner stop & start. It is dead centre of burner with black lead. Pull it out & clean it just in case. You really shouldn't be touching anything as you obviously havent much knowledge.
You need a oil engineer to be honest.

 

[WHPES]

Did you prime the pipework fully?

 

[Nostrum]

You could look at the photoell it wouldnt hurt, but it isn't going to cause the burner to fizzle out to nothing, there is either enough light or there isn't, it would more likely be clicking on and off rather than the flame dying.

The tiger loop presumably is fitted above the burner as per manufacturers instructions, so given the fact that air will rise, just running the boiler will shift the air up to the tiger loop, and providing it is working correctly, the tiger loop (de-aerator) will remove the air. Opening the bleed on the pump when it is converted to a 2 pipe system may just introduce air into the supply.

You need to look inside the tiger loop and confirm where the air is coming from, the oil line from the tank or the flow/return from the boiler. If it is coming from the return off the oil pump then check all the joints around the boiler.

Is the tank a top or bottom entry?