Trianco Oil Boiler start-up

[SJB060685]

I may have identified the problem. During the very wet weather while the boiler was inoperative for a number of hours, rain would have been entering the air intake in the balanced flue. It seems possible that when the boiler fired up there was heavily moisturised air being drawn in and this caused the problem of establishing a flame.

I was able to do a test yesterday having been out for 7 hours with the boiler not operating. In the past it would have had a problem establishing a flame but everything was OK. I think this is because we've had 3 days without rain. Time will tell! J.

Yes please let us know as I've never seen it before either

 

[JeremyB]

I will report back in due course. If you experienced guys haven't met up with this one before it seems rather unlikely that the problem is what I have described. Prior to doing the test yesterday I had also cleaned the contacts between the photoelectric cell and the control box (I have no reason to believe that good contact was not being made), and I richened the oil/air mixture by quarter of a turn. I really don't think the mixture was the reason for the problem not re-occurring because I had tried adjusting the mixture previously and had reverted to my 'datum' setting. Obviously, as has been recommended here, I need to get someone in to do a FGA. J.

 

[SJB060685]

As with any fuel burning appliance you need fuel, heat and oxygen to work as you know. If for some reason you have something or things affecting any one of those then improper combustion or even no combustion will occur. To avoid problems you need to ensure:
. Adequate combustion air.
. Correctly pressurised oil.
. Clean and dry and dirt free fan blades.
. The oil cant be too cold.
. Sufficient pull on flue, correctly sized and insulated.
. Good working order nozzle.

Do you ever check fan intake and impeller when servicing for any dirt/defects?

I highly doubt the contact between cell leads and control box were bad, if they were I'd be expecting lockout. The cell wont send a signal back to control box detecting false light during pre purge, burner would ignite, again no signal telling control box flame is established and would lockout, it usually wouldn't cycle on and off if the cell was dirty, faulty, obstructed, dodgy cable or poor connection, that's how these work.
You say you've adjusted the fuel to air ratio slightly, this needs to be done in conjunction with a FGA, theres no way of saying what you've now adjusted the CO2, CO and excess air too, mix that with randomly adjusting oil pressures and your boiler is most likely burning incorrectly, inefficiently and perhaps at a dangerous CO level.
Just so you know when you adjust the air, there is science behind this, not just fiddle. In temperatures we're experiencing now you would set the burner up with slightly more air and a lower CO2, doing that means when temperatures rise and ambient air becomes less dense then there is still sufficient air for combustion and it maintains a happy medium and continues to burn correctly.

I'm happy to help you out and guide you but it is important for you to know your limits and when it's time to get an engineer out. This is a fuel burning appliance after all and get it wrong and lives are at stake.

 

[JeremyB]

Thank you again SJB060685.

I routinely check the fan intake and impeller during the annual service. I have never found anything other than minimal dirt on the fan blades. The oil pressure is 110 psi and always has been when checked in the past. Earlier in this thread I mistakenly said that it was 70 psi, but that was my memory at fault

I do appreciate your helpful comments and I freely acknowledge that I am an amateur at this. As the quote says - "I know enough to be dangerous" Having said that I installed the boiler in the first place and have managed to keep it serviced and running successfully for over 20 years. I completely agree with you that I need to know my limits and obviously now is the time to get an engineer out. From a safety point of view it is of course essential that the boiler is set up correctly, but it is worth noting that it is located in a garage and has a CO detector nearby. If it was located indoors I would definitely not be taking such a 'casual' attitude to setting up the burning correctly.

I'm still inclined to think that possibly the problem with establishing a flame is related to excessively wet conditions over the past several weeks as mentioned in my previous post, but only time will tell if that is right. Thanks again. J.

 

[SJB060685]

The location of boiler is somewhat irrelevant to the CO, even when the boiler/burner is completely sound proof the products of combustion still exist through flue terminal and if the CO is high then this can affect anyone breathing it in, it only takes around 50/70ppm to be affected and in the region of around 150ppm can be fatal, this varies from individual as well, someone with underlying health conditions can be more susceptible than others. Also carbon monoxide testers need to be replaced from time to time.
Yes please keep us posted. If the problem is ongoing when the weather warms then we can take another look .