External boilers - sooty photocells

[Bunker]

I keep having ext boilers locking out, Ive schooled the (intelligent) customers into wiping the photocell - its only the blast tube area that gets a bit sooty.
It tends to happen when windy so I suspect its breeze up the pipe or negative pressure etc but some of the boilers are tucked away so doesnt make much sense.
Fed up with it, I spoke to Firebird today about it and the guy reckons theyve seen some problems with ext units being left under-aired. I confirmed that I tend to set up the gasses with the door off buut he reckons that as soon as you put it back on, you can hugely restrict the air flow. I saw the same thing on a Grant today - the louvres are quite inadequate.
So, TOP TIP: set it up, bang the door back on, re check gasses.

(then add a little air anyway)

Anyone else suffering this?

One boiler I put in 18 months has had it about 10 times now and they're getting a bit fed up. I thought about knocking up some holey baffles to mount in front of the flue. Any other ideas out there?

 

[Roger Welton]

I also believe it is due to the increase in ambient temp inside the boiler casing increasing when the casing is refitted.

Firebird have particular issues with the burner being at the top as it is, hence the new digi control box, they have also modded the terminal on the new external models to terminate vertically to try and prevent a back draught through the boiler.

 

[kimbo]

All boilers should be set up in their operating condition, in this case with the door on.firebird boilers have had this problem of sooting up for a while but it has been resolved with thethe digi box. There is no natural draught to take the fumes away so the new digi box has a 10sec post purge which gets rid of the gases before it sooty up the pc. You can buy a digibox kit to detroit or you can fit a 2 mtr plume dispersal kit which acts as a chimney and draws the gases away. I have fitted loads of both of these fixes under warranty. If the boiler is under 2yrs old it should be sorted out under the warranty.h

 

[Roger Welton]

Also of use on external boilers

http://www.rielloburners.co.uk/lumo/upload_documents/riello_combustionairadjustmentco2outsideair.pdf

 

[kimbo]

Also of use on external boilers

http://www.rielloburners.co.uk/lumo/upload_documents/riello_combustionairadjustmentco2outsideair.pdf

That applies to all balanced flue boilers summer and winter settings are different.

 

[Roger Welton]

BF boilers the charge air is heated as it passes though the flue so does not have such a marked impact as on externals.

 

[Bunker]

Thanks for that chaps, I guess unless you do a 6 monthly service, the boilers will be out of adjustment most of the time. I suppose doing it in in winter just means on the hotter days the boiler will just be over-aired but will be used much less anyway.