New Wall-mounted Oil Combi Boiler locks out in cold weather

[northyorks]

I wonder if anyone can help ?

I had a Grandee Oil Combi boiler installed in the autumn last year, it was commisssioned and seemed ok until it started to get cold, (less than 2-3 degrees celsius outside).

The CO2 setting at commissioning was 12% and CO 20ppm, and Flue gas temp 85 degrees c, the air inlet from outside is only short a few inches through the wall, and the air inlet valve setting has a scale between 1 and 6, originally set at 4.

When it is cold I can only get the boiler to fire and stay on when I turn this down to 2-2.5, but then the flue gas turns very sooty (and eventually it will go out (as the photocell needs cleaning off!), so typically I can turn it up to 3 again, but anymore and it will fail to start again.

When warmer weather comes again it will work happily at 3.5 to 4.

Annoying as when you really need it to work properly, is when it's cold!

Any help much appreciated.

 

[Tipper]

It could be that the tank outlet oil filter is icing due to the moisture content in the oil and restricting the flow of oil to the pump/burner when it gets down around 0C. Could also be a Tigerloop issue , is one fitted?

 

[northyorks]

It could be that the tank outlet oil filter is icing due to the moisture content in the oil and restricting the flow of oil to the pump/burner when it gets down around 0C. Could also be a Tigerloop issue , is one fitted?

Thanks for the quick reply

I'm pretty sure there's oil getting through as I can see it in a clear tube getting pulled through, not sure what a Tigerloop is ?

 

[oilman]

It's not the first that has locking out problems. I suspect a design fault in the burner. Stop playing with the air control and get Grandee to sort it, although if they find out what you've been doing, they may well say you're on your own. It's probably sooty as hell inside now, very inefficient.