Oil boiler keeps tripping out

colin79ie

Registered User
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370
I hope an expert on here can help me.

The other day my grant oil boiler started to trip out. By this I mean it starts and runs for about ten seconds and then stops. It does this repeatedly. The rads only get luke warm. There is sufficient fuel in the tank and I have tried the reset button to no avail. It was serviced a few months ago and worked fine up until this. Any ideas or suggestions appreciated before I fork out for a repair man.
 
I am sorry to say it could be any number of things, reset works only when the burner is on lock out but yours comes on intermittendly if I understand correctly.

Really sorry to say but I think you need to call some one, the wheater forecast is not great, It may not be possible to get someone quick (and if you say you are in a hurry there are some that will charge more) your on the right side of the week.

Sorry that is not what you want to hear.
 
The other day my grant oil boiler started to trip out. .
Tell it to chill, man ! :)

Seriously though, it could be airlocked, or dirt may have made it's way into it. It needs to be bled. Not too hard to do, but a bit messy.
 
That would be my initial reply, however not everyone is comfortable in doing this, and I would not be comfortable in advicing this on a web site.
 
Ok, as its a grant boiler, I will assume it's either a RDB riello or a g3-g5 riello

When you depress the reset button, the burner will run (on pre-purge) for 12 secs, if the lockout occurs after this time look at the following

a) the burner doesnt light at all
1) possible air lock if you previously ran outt of oil and just got a fill,bl0eed pump at bleed screw
2) lack of oil or line blockage
3) faulty solenoid coil
4) faulty control box
b) after purge the burner lights
1) faulty or dirty photocell
2) possible flue gas recycling
3) Pump not making required pressure

there is other option that could be at the root of this, but they cover all the usual ones
 
Our firebird (Riello burner) was tripping out and the rads only getting lukewarm. Turned out to be a simple airlock on the outflow of the boiler. There was a vent on the elbow luckily enough and one turn released a hiss of air and hot water could finally escape from the boiler. The first rads must have been (barely) heating through the return pipe or something as no hot water was to be felt in the outflow until bled.

It looked like a big problem but wasn't.
 
Folks,

I have a similar problem with my Riello 40 burner. For some reason it locks out intermittently during the day. Once the time clock kicks in the lockout loght on the control box comes on, there is no prepurge or ignition, just silence!
I've serviced the boiler, changed the control box, changed the capacitor, checked the air flow, checked the ignitors, and checked the wiring contacts. I'm still left with a burner that will only operate when it wants to!
The strangest thing is that when I press the reset button, it operates perfectly!!!!!

Any ideas would be greatly appreciated before I dig a hole in the back garden and bury it!
 
Folks,

I have a similar problem with my Riello 40 burner. For some reason it locks out intermittently during the day. Once the time clock kicks in the lockout loght on the control box comes on, there is no prepurge or ignition, just silence!
I've serviced the boiler, changed the control box, changed the capacitor, checked the air flow, checked the ignitors, and checked the wiring contacts. I'm still left with a burner that will only operate when it wants to!
The strangest thing is that when I press the reset button, it operates perfectly!!!!!

Any ideas would be greatly appreciated before I dig a hole in the back garden and bury it!


I feel your pain. I do it for a living and sometimes feel like taking a hammer to burners esp intermittent faults.

In my experiance a lot of intermittent faults are caused by a faulty solenoid. It may also be the photocell but they usually just stop working all together.
 
I would second the solenoid (they can go faulty when hot but work fine cold)

As for when the timeclock kicks in lockout lamp is on. The lockout occured at the end of a cycle not the start. Another possibility is flue gas recycling can cause this. Would need to see to diagnose though. Certainly try the solenoid is a good bet
 
Folks,

I have a similar problem with my Riello 40 burner. For some reason it locks out intermittently during the day.!

I'd be changing the wiring from the boiler thermostat, double check the earthing and then changing the thermostat itself. 1mm should be used. A hot thermostat may be causing a spike of power which messes with the electrics (RMS voltage) Do you live in an area with a few factories close by. During the day they would be calling more power which may be disrupting your power supply.
 
I'd be changing the wiring from the boiler thermostat, double check the earthing and then changing the thermostat itself. 1mm should be used. A hot thermostat may be causing a spike of power which messes with the electrics (RMS voltage) Do you live in an area with a few factories close by. During the day they would be calling more power which may be disrupting your power supply.

I like the way you think.
Depends on what boiler OP has. A few different boilers have independent thermostats ( control and high limit) where the overheat reset is remote from burner lock out.

OP, what type of boiler do you have?
 
Ok, as its a grant boiler, I will assume it's either a RDB riello or a g3-g5 riello

When you depress the reset button, the burner will run (on pre-purge) for 12 secs, if the lockout occurs after this time look at the following

a) the burner doesnt light at all
1) possible air lock if you previously ran outt of oil and just got a fill,bl0eed pump at bleed screw
2) lack of oil or line blockage
3) faulty solenoid coil
4) faulty control box
b) after purge the burner lights
1) faulty or dirty photocell
2) possible flue gas recycling
3) Pump not making required pressure

there is other option that could be at the root of this, but they cover all the usual ones
start with the easy ones to check first
lack of oil, air lock, dirty photocell
 
Thanks for the help folks! I'll give it another go and let ye know if its a boy or a girl!
 
forgive my ignorance. But how would a power spike send the burner into lockout through a thermostat?

The riello 40 (g3b as it is now) has no thermostat built in, there will be aseperate dual stat (ch/highlimit) contolling the flow of juice to the burner
Lockout is a function of the contolbox

Also if the correct fuse has been used on the system (5amp) will this not protect all components downstream in even of a spike?
 
forgive my ignorance. But how would a power spike send the burner into lockout through a thermostat?

The riello 40 (g3b as it is now) has no thermostat built in, there will be aseperate dual stat (ch/highlimit) contolling the flow of juice to the burner
Lockout is a function of the contolbox

Also if the correct fuse has been used on the system (5amp) will this not protect all components downstream in even of a spike?

The PCB board in your control box has various functions such as lockout, fire etc etc. That board would also bring the lockout process light on in the event of inadequte power (volts/amps) coming down the line. There is no fuse between the thermostat and the control box. While it is not covered in depth in the user manual, in the US, they have a port on the control box where you can get an RMS reading - I suspect they have more issues with "power" over there than we do. A regular socket board can take -+10% voltage slippage before encountering problems.
 
Always learning! Not a problem I have ever had. So never looked that deep into it. Nice info thanks
 
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