Atag XL110 Flueing issue

[Nico]

This may be a bit of a daft question but seem to be having issues with 4 Atag xl110 when running on low fire and believe there could be an issue with the flue but when check-in Mis I noticed it says flue gas outlets under pressured and flue gas outlets over pressured. What is the difference in these configurations? Cheers

 

[ShaunCorbs]

are you commercial ?

 

[Nico]

are you commercial ?

Yes but still at the learning stages

 

[ShaunCorbs]

whats the issue on low fire?

 

[Nico]

whats the issue on low fire?

The O2 percentage is meant to be between 5-7% there is 4 boilers back to back going onto a common flue header but when running on low fire the percentage was 12% when trying to adjust the offset on gas valve when I was getting to roughly 10% the CO ppm was flying through the roof. These are newly installed boilers but have used existing class 1 flue

 

[ShaunCorbs]

What was the high fire stats

 

[Nico]

What was the high fire stats

I managed to get the high fire to 4.7/4.8 which was reading MI's stated. So believe the POC may be struggling on low fire to leave the boiler and giving me poor readings

 

[ShaunCorbs]

Have you tried firing one boiler at a time on low ?

 

[Nico]

Have you tried firing one boiler at a time on low ?

I had done so thought the flue may be too long as the flue runs up a riser of a building.

 

[Nico]

Have you tried firing one boiler at a time on low ?

The bottom heat exchanger seems to be worse than the top making me think it's a Flueing issue as it's at a lower point again

 

[ShaunCorbs]

How long are the flue and is there a secondary flue fan fitted ?

 

[Nico]

How long are the flue and is there a secondary flue fan fitted ?

I haven't fully investigated flue length yet and no there is no secondary flue fan. Could this remedy the issue?

 

[ShaunCorbs]

Is could I would find out the max flue run on the Atags should be in the manual and then go from there

If you can’t find it phone tech up there a good bunch but commercial only so need to know what your talking about