Oil boiler - rapid cycling

[marshalln]

Hi,

We have had a bit of a saga with our oil boiler in the last two weeks. It stater going to lockout irregularly about twice a day, the first boiler man prodded and poked and I think introduced air in to the fuel line then walked of the job, refusing to come back. The second technician came yesterday and put an end to two days of no heat or hot water so that basically we are in a working condition.

The problem now is that the boiler is cycling every 5-20 seconds, whilst the fan remains on and is causing a strong smell of kerosene on the boiler vent side of the house. Does anybody have any rational explanation for this and what I might be able to do. I am an engineer by trade although I have no knowledge of the boiler internals beyond the sparse exploded diagram in the Servicing Manual provided with the boiler. The boiler is a Trianco Eurostar 60 - 70 with a Riello burner and Danfoss oil pump.

 

[Tibbot]

The boiler is a Trianco Eurostar 60 - 70 with a Riello burner and Danfoss oil pump.

Check that again Riello burners only have Riello oil pumps. Trianco Eurostar usually has Ecoflam or Sterling burner.

If it's balanced flue, problem maybe recycling of POC's causing oxygen depletion to burner.

 

[marshalln]

I don't now what pumps usually come with a Riello, I'm only reading the manual. The boiler is about 10 years old so may have been made before Riello decided to fit their own pumps.

What is POC, I'm not familiar with the achronyms associated with boilers.

So if the flue has a problem it has occurred due to the technicians visit? and can be tested by removing the front cover from the burner so that the air comes direct rather than through flue.

Further info, the rapid cycling occurred before the boiler got up to the temperature set by it's own internal thermostat.

 

[Tibbot]

The boiler is about 10 years old so may have been made before Riello decided to fit their own pumps.

Riello burners only have Riello oil pumps.

 

[marshalln]

I checked the filter by the tank, it hasn't been looked at for over 7 years and it was choked with gunk and dirty water. After washing it out I tried flushing the line from the tank to the filter by opening up the valve (carefully). Nothing!
When I dis-assembled the fittings after the valve, they were choked with more black gunk. After lots of cleaning I put it all back together and the boiler is now running properly.

 

[casius66]

The filter should be checked at each service (if accessible) - when was it last serviced? I dip the tank at each service with water finding paste to check for carp at bottom of tank.
Is it a metal or plastic tank?
Gas oil or kerosene?
How much water in filter?

 

[WDIK]

Id be looking at the photocell not detecting flame. but then im just a tO$$ER