Riello 40 issues

[rog2e]

I have a Riello 40 oil burner on a Buderus boiler. About two weeks ago I noticed that any time the boiler would kick in to heat the water, the Riello would start up into its pre-purge cycle and then when the fire ignited it immediately shut off, the Riello was still humming along and about a couple seconds later it ignited the fire but again the fire immediately shut off, on the third try the fire stayed on. I didn't think anything of it but a few days later I noticed it started to do this on and off thing more and more so that now the burner would go on by the 5th try. In addition, now 2 weeks later sometimes the burn cycle would not heat the water to the upper limit and the up and down process would start happen again until the upper limit was reached. I'm sure that is not good for the system.
Can someone tell me what is causing this. I've looked around and have seen things about the CAD cell or changing out the nozzle both seem doable, but before I start can anyone say for sure what it might be?

 

[muggles]

I'd say either a solenoid or a photocell issue most likely

 

[Spark74]

Agree with muggles ​

 

[oilhead]

When was it last serviced? The symptoms are typical of dirty combustion head, or maybe from a carboned up heat exchanger. You need to follow a logical service sequence instead of adopting a piecemeal approach.

 

[rog2e]

Well I just wanted to update for someone else. I had a heating tech come in and upon hearing it he said it is acting like there is too much air getting in the system. Upon closer inspection he pointed out to me that the Tigerloop compontent had a lot of silicone around it as if someone had tried to repair it. Suffice it to say he did a regular maintenance on the whole system and replaced the Tigerloop. So all in all it was 180 for the maintenance and 170 for the Tigerloop. Now I wasn't down there watching him so who knows if the regular maintenance would of fixed it, but I was fine with the Tigerloop because I saw what he was saying about the silicone even though there was no leaking at all.

 

[oilhead]

Tiger Loops don't necessarily show evidence of leaking. The big problem is if they allow air in when the burner tries to pull fuel through.