Trianco Combi 70 Weirdness

[ManxMax]

Hi all
Wonder if anyone has an idea of what is going on with my eccentric Trianco oil boiler - which would have never worked at all if it hadn't been for the help I received on this forum. Thanks to those concerned.
Anyway, the thing used to trip the little button under the control box at random, so it seemed, except when I was running the DHW and, generally, when the heating was on. Well, with no heating on over summer it has developed some quirky behaviour: it fires up, on auto, for a few seconds, shuts off the burner for a couple of seconds and then fires up again. Does this maybe 10 times before it gets going. Strange thing is that it rarely trips out anymore.
I'm wondering if it's a thermocouple or something. Any help gratefully received. Soon be time to get the CH going again, so could do with sorting this.
Cheers

 

[Agile]

I doubt it will be a thermocouple!

Do you get it serviced ( by John ) regularly?

Tony

 

[ManxMax]

I doubt it will be a thermocouple!

Do you get it serviced ( by John ) regularly?

Tony

Can't get anyone to service it here on the Isle of Man - heating engineers are not interested unless they installed it or you need a new installation. Serviced it myself last autumn - oil pressure was fine, but I don't have equipment to do a CO2 test.
Wondering if it might be a dirty photocell. I'll give it a service next week and see what happens. Just didn't want to get it stripped down and find I need parts and be without hot water until they arrive (can't get most parts for it here) if it's a common problem.
Cheers anyway.

 

[Agile]

When was the photocell window last cleaned?

If the combustion is not correct then that can get more sooted!

Setting the combustion conditions is about the most important aspect of oil servicing!

Would the local OIL guys agree what what you say about them?

Tony

 

[dcawkwell]

Clean out
A new nozzle.


Then if that hasn't cured it
Possibly solenoid, solenoid coil or photocell.

 

[Agile]

Changing nozzles etc. all without an FGA?

 

[dcawkwell]

Changing nozzles etc. all without an FGA?

Well it isn't running right as is. If he doesn't do something
soon it will burn out the transformer.
Usually if the burner is correctly adjusted changing a nozzle will
only affect the burn slightly. You can adjust an oil boiler reasonable
with just a smoke pump. Won't be perfect but it will be close enough to
run happily.

 

[Mike2007]

Oil flow and cleanliness is usually the main culprit for oil burner problems. These units are fairly bomb proof, but the oil storage and filtration must be excellent, otherwise lots of c**p is dragged into the supply system. This creates weird firing patterns.
Change all filters where possible and strip and clean right up to and inside pump. Maybe blow through oil lines as well.