Trianco oil boiler burner lock out problem

[Ash Burton]

Having a problem just in the last few weeks with our Trianco oil fired combi-boiler burner locking out on timer start up.

Have replaced the Danfoss coil and photo-cell but the lock out light still comes on periodically at start up, the burner will start by pushing the restart button until the next programmed start time.

The oil tank is full, the burner nozzle was replaced at the annual service in May and the input supply voltage is a steady 245v.

I've tried leaving the hot water switched on permanently but it still locks out at the next restart after the water temperature stat operates.

Any suggestions as to what the problem could be?

Ash

--- news://freenews.netfront.net/ - complaints: [e-mail] ---

[Dave Liquorice]

Have you watched it try and fail to run?

Does the blower run? Do you get a spray of fuel? Do you get a flame? What colour is the flame? Water in the fuel, that can do weird things if it gets past the pump. Air leak on the suction side of pump?

[Michael Chare]

Apart from the pump itself, you may need to replace any filters between the tank and the pump.

[Ash Burton]

Thanks for the useful responses;

The tank filter was replaced recently, i've not yet watched it try to start as it is set to come on before i get up.

It fires OK when i press the reset button, so it would seem the oil is getting thru OK, the tank was recently refilled after the annual boiler service in May in which the oil is normally checked for water contamination, it's possible the new oil has water in it, although it ran OK for a few weeks before this problem occurred?

It's possible there could be an air leak' i'll check that out, the frustrating thing is it fires as normal about 50% of the time, so it does seem to indicate something variable.

--- news://freenews.netfront.net/ - complaints: [e-mail] ---

[harry]

Check/clean the ignitor /spark plug thingy. Also loose connections on the ignitor circuit,. Sounds like loose connection somewhere.

As someone else has said, water in fuel. Check if there is a drain tap on the fuel tank, if so open & catch what comes out, see if water or oil.

[Dave Liquorice]

Filling the tank stirs it up, kak will get drawn into the system. A new filter shouldn't object that quickly though unless there is a lot of kak in the tank. Did you see the old filter, does the housing look as if it's been opened recently?

A flake of something can act as a butterfly valve. Or a small bit a kak gets drawn to a small orfice blocks it, boiler shuts down, kak drifts away from orfice until boiler starts, rinse and repeat... Similar can happen with a flake across the pipe. Not quite your symptoms.

Water in a tank mainly come from condensation inside or rain getting blown into vents/filler cap etc.

How long elapses between the boiler running and then failing to start? Will it reliably start up to around that time?

Is the oil gravity fed or is there a need to lift it a bit? Single or dual pipe system?

[Michael Chare]

A gauge to check the oil pressure is not that expensive.

[Martin Brown]

One I have seen with not unlike the symptoms you report is where the solenoid valve wasn't quite closing completely and overnight there would be a small amount of kerosene leaking from the spray nozzle.

The first ignite would burn it off but fail with a bad flame lockout. The photocell becoming sooty after a few weeks of this in addition.

Subsequent restart would almost always work OK.

Basically you need to delay the overnight start so that you can watch it and see what actually happens.

Another scary one is a leak on the exhaust side of the boiler. This tends to result in more noise and in extremis escape of very hot gasses. Again you get unexplained lockouts for bad/unstable flame.

[Ash Burton]

Ans. Usually from 10 at night to 7 in the morning. Lock out occurs mainly in the morning but the burner will start immediately when manually reset.

Ans. The oil is gravity fed by single pipe from the tank which is approx

1 metre above ground (and boiler) level.

--- news://freenews.netfront.net/ - complaints: [e-mail] ---

[Ash Burton]

That seems quite plausible, i will check that out .

Thanks,

I haven't noticed any of those symptoms, we have a carbon monoxide detector in the boiler room which should operate if there was an exhaust leak.

--- news://freenews.netfront.net/ - complaints: [e-mail] ---

[Dave Liquorice]

You'd probably notice the smell before the CO alarm. Oil exhaust is a bit niffy and not like kerosene.

Also CO alarms aren't like smoke alarms, they have various levels of "alarm" depending on the concentration and duration of the CO precense. Might start by just flashing a red light, progress to flashing light but faster with a beep and eventually a non stop sounder "get the F out" full alarm.

A case of RTFM but if your FM is like the FM for our CO alarm it's as clear as mud.

[Dave Liquorice]

The leaky solenoid valve Mentioned by Mr Brown fits that, especially if it'll reliably start during the day.

[Ash Burton]

Thanks for all the responses, curiously the boiler has been behaving itself for the past two weeks, starting as normal on the automatic timer.

Could it be that there was a small fragment of dirt (or water contamination) in the oil feed which has cleared itself?

Another possibility suggested by Trianco is that if the electricity supply voltage was below 230v that could cause the problem. I have had that checked by the network operator and it seems some work is needed in that regard.

--- news://freenews.netfront.net/ - complaints: [e-mail] ---

[Dave Liquorice]

I think I'd put more money on that than:

The lower limit is 216 V (230 - 6%). IIRC this problem was a morning thing after not being called on for > 8 hrs or so. In my experience the voltage floats high during the night as there is little load and drops back to the "normal range" between 0600 and 0800.

Currently our ovenight voltage is about 255 droping to just under 240 by 0800. Yes I have complained to the DNO, there is some line work going on and the local substation is being fed by a different source/route. When i first complained they knocked 200 V off a 33 kV regulator that made the expected drop but still outside the limit, another 200 V and we were just under but it's gone back up recently.

Our supply is normally rock solid at 240 V +/- 5 V at the extremes,

24/7.

[Ash Burton]

I spoke to soon, it locked out again this morning on timer start up....Doh Ash

--- news://freenews.netfront.net/ - complaints: [e-mail] ---

[Ash Burton]

Well after a protracted period of uncertainty over if the boiler would start up or lock out in the mornings, things finally came to a head last friday when it would not start at all.

It turned out to be that the ignition transformer was at fault, must have been failing for a while and then eventually gave up the ghost.

A replacement has been fitted and it is stating normally again.

Thanks to all who gave constructive comments. Ash

--- news://freenews.netfront.net/ - complaints: [e-mail] ---