oil burner lockout

[BC59]

Hi

I'm experiencing lockout problems which on the face of it seem quite random. My burner is a very old Selectos D42/A and the control box an equally ancient Danfoss 57H3.

It seems random because sometimes it goes to lockout before firing and sometimes after firing; and when I say after firing I mean several hours!

There's plenty of oil in the tank too.

About 6-8 weeks ago I had an underground tank fitted and a tigerloop. Everything was ok until last week and then I had the first lock out. It restarts perfectly everytime I reset - just one push and it fires.

Any advice would be appreciated.

 

[dontknowitall]

I assume you've checked the photocell is clean, but the lockout from a dirty one occurs after the flame is there for a little while, as opposed to locking out before firing.

I'm wondering if there's enough oil being pumped through. If it was fine 6-8 weeks ago when the tank was full, the level might now be low enough that it's not supplying enough oil. A tiger loop just releases air from the oil and doesn't pump the oil.

If the oil tank is above the boiler you don't need to pump it as the flow falls with gravity. If the tank is below ground you have to pump the oil up to the boiler.

I suspect that once it fires, it will continue (assuming all is in order) until the heat is no longer needed, because the pump in the burner will be pulling the oil through fast enough, but once the burner pump stops then the oil will probably fall back and create an air lock.

I might be talking a whole load of rubbish here and I'd wait for another opinion if I were you, but I've just suggested these things as possible pointers to the problem.

 

[BC59]

Thanks for the reply. Yes I've checked the photocell and cleaned it for good measure. As to the pumping issue, the Tigerloop works in such a way that it eliminates the need for a pump. It is a fairly standard application as far as I can tell and the install instructions provide details for tanks both above and below burner level so I don't think that is causing the problem.

 

[John Flower]

Have you checked for debris /water in the filters. When the boiler fires and the pump runs it could be slowly sucking debris into the filters restricting the oil flow to the burner. When the boiler stops the debris falls away from the filter and the process starts again. Just because the tank is new dosnt preclude this problem especially if the existing oil supply pipework was utillised. Even new oil can contain small particles which settle in the lowest parts of the tank.

 

[dontknowitall]

BC59 - I've had another thought (based on a recent problem I came across). Is the water pressure high enough? A friend (who lives miles away from me) had boiler problems and the engineer established that the water pressure wasn't enough to keep the boiler going and it kept cutting out.

Re the tiger loop, I wasn't sure and that's why I suggested you wait for another opinion!

 

[BC59]

Mine is a vented system so i don't think water pressure is an issue.

 

[buffy27]

give the boiler/burner a full service. clean photo cell.electrode s [light rub of fine sand paper]clean porcelain holder.clean fire cone,swap the atomizer {making sure its exact one for model] have a look around unit for any signs of loose or charred electrics.check air intake{set correctly for model specifics]. not familiar with this model but open boiler and clean with wire brush{take out baffels},
go to oil tank make sure its sealed{water can cause random lockout if in kerosene]
open oil filter {check for build up of ****e]
follow line and check for leaks{air]
check out tiger loop {no leaks}
make sure fire valve is fully open

another thing could b an issue with the circulation in the primary circuit.{flow and return] this would prevent the hot water leaving the chamber and then she d cut out on the high limit stat{ maybe fault with pump/motorised valve etc]
is the pump is controlled by a pipe stat.
let me know what the craic is buffy

 

[BC59]

Thanks Buffy.

Serviced burner and even replaced oil pump.

No joy! But yesterday morning when inspecting the tigerloop I noticed a distinct lack of fuel.

Does this suggest either a blockage or an airleak?

 

[buffy27]

whats the craic,
why did u replace oil pump.
was there any loose connections on circulation loop .
let me know please.
buffy

 

[justlead1]

Hi. I experienced a situation some time ago on an isolated property. The cut out seemed random, after days of checks i found it to be electric supply surge/drop that confused the controller. Good luck

 

[BC59]

whats the craic,
why did u replace oil pump.
was there any loose connections on circulation loop .
let me know please.
buffy

Hi Buffy. The plumber who did the original install said at the time that he suspected that the pump was on its "last legs" so when I called him he advised replacing the pump which I did.

I called him back to site because it wasn't working even with the new pump. He replaced the control box and some pipework I noticed was badly bent i.e. was kinked. he also installed a non return valve on the line from tank to tigerloop - hey presto it's working.

I guess it could have been any one of these things by itself (?) but I'm just so relieved to have the thing running again; last week was so cold without it!

Thanks for your help.