About 12 days ago attended a boiler lock out. Apparently another plumber was there a week before to and adjusted the photo cell. ..
It is a grant wall 16/21 about 10yrs old. The ones where there is no room to move ...! Doesn't look like serviced much. Opened up and heavily sooted. Bottom baffle warped and 3 tabulators completely stuck. Managed to get stuck damaged tabulators out and replaced as well as new baffles. Gave it a good clean and added 2xnew longlife hoses (still had original braided ones) added filters on fuel line as had non.
New Nozzle set combustion as per MI (air a little higher than I normally have for these) but CO2 11.8% Exess air 31.4% co 16ppm temp 68deg.
Thought all good probably just needed a proper service.
Over weekend it locked out. Went today and sooted again (not as bad as before) but nozzle and blast tube black. Checked and small oil stream from nozzle after shut down. Presumed this is the sooting problem. Pump filter not great so just changed the pump with coil. and new nozzle.
Went to set it up to MI and with mid 19.3 KW setting at 10 bar, I had to open air damper right up past 8 (normally about 3 for this boiler) to get 12.2% co2. Smoke settings OK.
After adjusting for a while and lowering pressure a bit to get fair readings but was unsettled by air setting still being way near fully open.
I ended up lowering the pressure to 7 bar as the 17 KW range had the same size nozzle @ 7 bar and air damper back down to about 3. Got readings of Co2 11.2, Co 23ppm, Flue temp 75.4 Deg (bit higher than MI max) Xair 37.5 96.9 % efficiency. Good smoke setting 0-1
Anyone with any ideas why I struggled to get good readings at the MI 10 Bar pressure setting. I thought it might be a poor nozzle?
Could a worn / slipping fan produce less air than normal but same oil pressure?
I have offered to go back next week and recheck.
Any Thoughts.
Thanks
It is a grant wall 16/21 about 10yrs old. The ones where there is no room to move ...! Doesn't look like serviced much. Opened up and heavily sooted. Bottom baffle warped and 3 tabulators completely stuck. Managed to get stuck damaged tabulators out and replaced as well as new baffles. Gave it a good clean and added 2xnew longlife hoses (still had original braided ones) added filters on fuel line as had non.
New Nozzle set combustion as per MI (air a little higher than I normally have for these) but CO2 11.8% Exess air 31.4% co 16ppm temp 68deg.
Thought all good probably just needed a proper service.
Over weekend it locked out. Went today and sooted again (not as bad as before) but nozzle and blast tube black. Checked and small oil stream from nozzle after shut down. Presumed this is the sooting problem. Pump filter not great so just changed the pump with coil. and new nozzle.
Went to set it up to MI and with mid 19.3 KW setting at 10 bar, I had to open air damper right up past 8 (normally about 3 for this boiler) to get 12.2% co2. Smoke settings OK.
After adjusting for a while and lowering pressure a bit to get fair readings but was unsettled by air setting still being way near fully open.
I ended up lowering the pressure to 7 bar as the 17 KW range had the same size nozzle @ 7 bar and air damper back down to about 3. Got readings of Co2 11.2, Co 23ppm, Flue temp 75.4 Deg (bit higher than MI max) Xair 37.5 96.9 % efficiency. Good smoke setting 0-1
Anyone with any ideas why I struggled to get good readings at the MI 10 Bar pressure setting. I thought it might be a poor nozzle?
Could a worn / slipping fan produce less air than normal but same oil pressure?
I have offered to go back next week and recheck.
Any Thoughts.
Thanks
