Riello 25/32 RDB 2.2 De-rating

[Fly100]

Hello all,

 

Is it possible to De-rate a Greenstar Danesmoor Riello 25/32 RDB 2.2 ? Long story short it appears the boiler is significantly over rated, I'd like to reduce it to 18kw ( oil reduction is approx 1L and hour less consumption). Would it be possible to find the differnet parts between a Riello 25/32 RDB 2.2 & Riello 18/25 RDB 2.2 and de-rate it that way or is it a case of a whole new burner and or boiler ?

Ive checked the physical side and the dimms are the same, checking the Riello parts list between the 2 there are some differnet parts obviously but the core parts appear to same across the range. Of course the work would be done by an OFTEC reg Engineer we use.

Thanks for any info / thoughts.

FLY

[ProDave]

You should be able to de rate it by changing the burner jet but you will need an OFTEC plumber with a flue gas analyser as the burner will need to be set up from scratch with new air settings etc to get the combustion right.

[Fly100]

2 minutes ago, ProDave said:

You should be able to de rate it by changing the burner jet but you will need an OFTEC plumber with a flue gas analyser as the burner will need to be set up from scratch with new air settings etc to get the combustion right.

Its already on the lowest jet possible = 25kw

[dpmiller]

The right engineer would set it up correctly with a smaller jet, specs be damned. Being pedantic you'd probably change the blast tube too, but the look of a clean flame inside the combustion chamber and good numbers on the analyser, and you're good to go IMHO.

[Fly100]

49 minutes ago, dpmiller said:

The right engineer would set it up correctly with a smaller jet, specs be damned. Being pedantic you'd probably change the blast tube too, but the look of a clean flame inside the combustion chamber and good numbers on the analyser, and you're good to go IMHO.

So in short your saying fit a lower jet and set the pump psi as per book run it on the analyser ( little bit of tweeking) and im going to be good to go ?

[ProDave]

The issue might be getting the airflow low enough, iirc it's a fixed fan operating from the oil pump motor and the airflow is adjusted with baffles.  You might run out of adjustment? Perhaps the smaller burner has a smaller fan?  but if the boiler at our last rental property was anything to go on, it was old and tired and he could only just get the airflow high enough.

[dpmiller]

That's why I mentioned the blast tube, they have different hole/ blade/ length configurations