Firebird condenser boiler problem

MAYOMICK

I had a firebird condenser boiler fitted early last year (Riello Burner) and since I have had it fitted the photo cell has to be cleaned regularly.It was commissioned after fitting and I also had it serviced at the end of 2011 by technician using a gas analyser but the problem still persists.Has anyone any ideas of what the problem might be and what I should do as I need to get it sorted before the guarantee runs out (2 Years?)

JohnnieK

Co2 is out. Maybe his analyser was knackered. Also if it got sooty before the whole inside must be cleaned out before re-commissioning.

kscobie

Contact Firebird directly, they will get a service engineer out, i had this with the last 2 i fitted, even though i commissioned them myself, and were perect when i left.
They fitted a plume kit on one and adjusted the output way down on the other.:)

spireland32

kscobie wrote: »

Contact Firebird directly, they will get a service engineer out, i had this with the last 2 i fitted, even though i commissioned them myself, and were perect when i left.
They fitted a plume kit on one and adjusted the output way down on the other.:)

I had the same, firebird came out numerous times... Did this did that no joy. Told to fit plume kit... Sorted

DGOBS

Best way is to de-rate the boiler

i.e. reduce the nozzle size by about .05 us/gal and compensate by increasing oil pressure to increase throughput to give the same boiler output, the pressure increase in the combustion chamber will help overcome the issue.

Other issue that cause the same effect is flue gas recycling, especially if the boiler is balanced flued and the terminal is in a restricted area such as a side passage, have the technician drill a small 'air' test hole on the burner snorkel (make sure to have him seal it afterwards) and then carry out an O2 test on the air intake to prove there is no recycling of flue gas back to the burner from either the terminal (which would be rectified by the plume kit) or a defective seal on the flue.

This could also be a result in an outdoor module if any seal at the burner, combustion chamber door or flue connection is defective, again polluting the air intake.

CO2% should be approx 11.5% with ALL COVERS ON, if it's fresh sharp day (good air quality) I would leave the CO2% to about 11% as this will change to 11.5-12% on a muggy day.

COppm should be less that 30ppm.

Make sure the nozzle is no 'choking up' if so, possible the the electrodes are in the wrong position, impinging the fuel causing sooting

Finally, have them check the inside of the blast tube after running for a few minutes, if the is any 'wetness' or 'blackening' there I would suspect the burner nozzle holder has a hairline crack, this will cause the PE cell to soot up very quickly, i have had a few where this has happened to a burner less than a year old.

The clue here as always would be, where is the soot?
PE cell, nozzle, blast tube, combustion chamber, baffles/heatexchanger, terminal, they all lead to different conclusions as to whats going on!

The problem here is, a lot of technicians are grand when everythings running good, but rubbish when there is a problem that actually requires a bit of thought........;)

spireland32

DGOBS wrote: »

Best way is to de-rate the boiler

i.e. reduce the nozzle size by about .05 us/gal and compensate by increasing oil pressure to increase throughput to give the same boiler output, the pressure increase in the combustion chamber will help overcome the issue.

Other issue that cause the same effect is flue gas recycling, especially if the boiler is balanced flued and the terminal is in a restricted area such as a side passage, have the technician drill a small 'air' test hole on the burner snorkel (make sure to have him seal it afterwards) and then carry out an O2 test on the air intake to prove there is no recycling of flue gas back to the burner from either the terminal (which would be rectified by the plume kit) or a defective seal on the flue.

This could also be a result in an outdoor module if any seal at the burner, combustion chamber door or flue connection is defective, again polluting the air intake.

CO2% should be approx 11.5% with ALL COVERS ON, if it's fresh sharp day (good air quality) I would leave the CO2% to about 11% as this will change to 11.5-12% on a muggy day.

COppm should be less that 30ppm.

Make sure the nozzle is no 'choking up' if so, possible the the electrodes are in the wrong position, impinging the fuel causing sooting

Finally, have them check the inside of the blast tube after running for a few minutes, if the is any 'wetness' or 'blackening' there I would suspect the burner nozzle holder has a hairline crack, this will cause the PE cell to soot up very quickly, i have had a few where this has happened to a burner less than a year old.

The clue here as always would be, where is the soot?
PE cell, nozzle, blast tube, combustion chamber, baffles/heatexchanger, terminal, they all lead to different conclusions as to whats going on!

The problem here is, a lot of technicians are grand when everythings running good, but rubbish when there is a problem that actually requires a bit of thought........;)

Great bit of info there, I'm not involed in the service side myself but good to know why it's happening. You are spot on the one I had problems with was an outdoor in a side passage! Is it just pressure on the flue causing the POC back down into the boiler?

DGOBS

Partially IMHO

If you look at the flue design, it exits up the back of the appliance, the passageway is about 125mm long, yet only about 15-20mm wide, and I
think this combined with the restriction of the condensing heat exchanger
has to have some effect on the combustion chamber.

I only feel this as have seen a lot of them with soot only at the PE cell, and maybe some slight sooting of the combustion chamber, yet flue terminal and
lower baffles remaining reasonably clean

Found I got most success in de-rating and increasing the oil pressure

shane0007

DGOBS wrote: »

Partially IMHO

If you look at the flue design, it exits up the back of the appliance, the passageway is about 125mm long, yet only about 15-20mm wide, and I
think this combined with the restriction of the condensing heat exchanger
has to have some effect on the combustion chamber.

I only feel this as have seen a lot of them with soot only at the PE cell, and maybe some slight sooting of the combustion chamber, yet flue terminal and
lower baffles remaining reasonably clean

Found I got most success in de-rating and increasing the oil pressure

Completely agree. You will find that the sooting of the photocell mainly only happens on windy days. Downsizing is probably the best solution.
If it is a re-cycling issue, then Firebird are now issueing a air-intake guard with their flues but I found the issue to be more as what DGOBS points to.

JohnnieK

DGOBS wrote: »

Partially IMHO

If you look at the flue design, it exits up the back of the appliance, the passageway is about 125mm long, yet only about 15-20mm wide, and I
think this combined with the restriction of the condensing heat exchanger
has to have some effect on the combustion chamber.

I only feel this as have seen a lot of them with soot only at the PE cell, and maybe some slight sooting of the combustion chamber, yet flue terminal and
lower baffles remaining reasonably clean

Found I got most success in de-rating and increasing the oil pressure

You wouldn't get that with a GRANT Tony

DGOBS

Sure wouldn't.

BUT......

ever tried servicing one that hasn't had attention in 2 or more years, getting those baffles out is mighty fun! Dreading them in a few years time, time to get the angle grinder out!

MAYOMICK

Thanks for all the replies.A Firebird technician called and fitted a short plume kit and adjusted settings CO2 11.6% and CO 16ppm so its wait and see how it goes.

shane0007

MAYOMICK wrote: »

Thanks for all the replies.A Firebird technician called and fitted a short plume kit and adjusted settings CO2 11.6% and CO 16ppm so its wait and see how it goes.

I reckon the next windy day you will be getting him back. 11.6% IMHO is a bit high. I would have done as DGOBS said and de-rated the burner with a lower CO2 and upped the pump pressure.

kscobie

shane0007 wrote: »

I reckon the next windy day you will be getting him back. 11.6% IMHO is a bit high. I would have done as DGOBS said and de-rated the burner with a lower CO2 and upped the pump pressure.

+1