Trianco eurostar 65 will fire but not stay lit

[B7TMW]

Hi. A newbie here. Have good DIY skills but central heating kinda goes over my head??

My Trianco is 10 years old. Has run faultlessly all this time until recently.

All of a sudden we have no hot water. Boiler stone cold and has not appeared to run. Press the button (lit orange) on the relay box and bingo, she fires (fan runs fine). I can then here it going out then relighting in random pattern. No air bubbles in the oil feed and plenty in the tank.

This happened couple of weeks ago and he above sequence cured it and it has ran no issues until now.

Stats working fine. It gets to stat temp and cuts out. Wind the stat up and it fires. Worth mentioning that at this point the orange light on the relay box is NOT lit.

Any ideas. I've looked for diagrams to strip it (not afraid of stripping it down if I know what I'm looking for).

I'm thinking partially blocked jet or something similar????

Any suggestions greatly appreciated. Thanks

 

[snb]

sounds like it could need a service. possibly the photocell needs cleaning/replacing caused by poor combustion.

 

[Burnerman]

I'm wondering when your boiler was last cleaned out, and the burner serviced?
Anyway there are a few things that need checking out.
The photocell needs to be clean (although this generally allows the burner to start and then lock out after a few seconds)
The coil on the top of the oil pump is notorious for failing, especially when it gets warm, and the oil pressure at the pump needs to be checked.
Ideally, a full flue gas analysis should be taken, with a smoke test done first.
Before any burner repairs or adjustments, the boiler baffles and flue ways must be cleaned out first.
John

 

[B7TMW]

Not sure when it was last serviced to be honest.

Funny thing is, Once it's up to temp, it runs perfectly (i.e. when it's hot.) It seems to be the initial start up, i.e. when the boiler is stone cold, that the issue is at it's worst. When we run out of hot water, the boiler stat shows the boiler as cold, i.e it clicks virtually at it's off point at 12 o clock on the dial.

Could it still be oil pump coil when it runs fine when hot?

Now for a sily question, How do i get to the photo cell to clean it?

I've also read about the balanced flue seals being an issue?

 

[Burnerman]

Its a bit difficult to answer your questions for certain, but when the boiler is cold then the air in the flue is denser and more difficult to push out of the way...if you have a short balanced flue though, this shouldn't be relevant.
The photocell is a light dependant resistor that constantly looks at the burner flame. If it sees light, it keeps the burner switched on - if it doesn't then it assumes that the flame is out and turns the burner off.
The photocell has a wire connection that plugs into the back of the burner, but some types (riello) its contained within the control box on top of the burner. I'm not sure which burner you have, but I'll try to find out....
If you have a balanced flue, then the burner will be contained in its own airtight box. You can unclip this box so that the burner gets its combustion air from the room - this may help things.
Oil pump coils either fail completely or fail when they get warm - often coming back to life after they have cooled down.
I'm really not trying to sound patronising here, but the boiler and burner should really be serviced yearly, have the pump pressure taken and a smoke test and flue gas analysis should be done to set the thing up - it can't be done by eye!
It goes without saying that the tank filter should be clean, and likewise the one in the pump.
Its a good idea to replace the nozzle too - its not strictly necessary to do this every year but they are cheap enough.
John

 

[B7TMW]

Its a bit difficult to answer your questions for certain, but when the boiler is cold then the air in the flue is denser and more difficult to push out of the way...if you have a short balanced flue though, this shouldn't be relevant.
The photocell is a light dependant resistor that constantly looks at the burner flame. If it sees light, it keeps the burner switched on - if it doesn't then it assumes that the flame is out and turns the burner off.
The photocell has a wire connection that plugs into the back of the burner, but some types (riello) its contained within the control box on top of the burner. I'm not sure which burner you have, but I'll try to find out....
If you have a balanced flue, then the burner will be contained in its own airtight box. You can unclip this box so that the burner gets its combustion air from the room - this may help things.
Oil pump coils either fail completely or fail when they get warm - often coming back to life after they have cooled down.
I'm really not trying to sound patronising here, but the boiler and burner should really be serviced yearly, have the pump pressure taken and a smoke test and flue gas analysis should be done to set the thing up - it can't be done by eye!
It goes without saying that the tank filter should be clean, and likewise the one in the pump.
Its a good idea to replace the nozzle too - its not strictly necessary to do this every year but they are cheap enough.
John

John, Thanks for that. It gives me something more to go on. You are right, it will need a service. However, I am wary due to a previous oil fired boiler I had was serviced every year prior to me moving in and we kept up the same servicing. Bang on cue, every year, it would fail to light, Call out the service guy who alledgedly knew the boiler and he'd clean it out, and it'd run for another year. I sussed it when I decided to investigate and found it was purposely set over rich. I weakened the mixture and it ran fine for another 4 years without a glitch

So I guess I'm a bit along the lines of "been burnt before" kinda thing.
Thanks again