Riello burner not firing

Cona

Grant vortex combi boiler ran out of fuel. Got a top up and bled the line. Tried a few times to reset it but the boiler wasn’t firing. Now it seems like it tries to fire but isn’t, but the lockout doesn’t come on. The boiler just seems to be humming away as if it’s trying to fire.

Any ideas? I have switched it off now as I’m worried something is seriously wrong now. Water pressure is 1.5 bar. That’s as far as my knowledge goes unfortunately

John.G

This thread may help if you have the same model Riello.

https://www.boards.ie/vbulletin/showthread.php?p=102119691

Cona

Thanks but I have already bled the fuel line so that isn’t the problem I think. I initially pressed the reset button on burner and the boiler tried to fire but eventually cut out a few times. So I kept bleeding and pressed reset. I’m sure the line is well bled as I took out a good bit of oil just to be sure

Now it turns on and tries to fire but isn’t firing up. It also doesn’t cut out so it’s kind of stuck with the ‘burner’ light on, and the boiler not lit.

Probably gone beyond my skills levels to repair but was hoping for a simple fix if at all possible...

Wearb

Likely to be cell or pump...or poor oil supply. Most likely cell.

John.G

Could (now) be cell alright , in my (2005) model G5X manual it states Fault: "Burner only works in the Prepurge" Possible cause: "The photoresistance sees false light" Solution: "Eliminate the light" so propably needs the cell changing?

Cona

With regards to the cell being gone...what is the photocells function in the boiler from day to day?

Reason I ask is that the boiler was working perfectly this morning, then ran out of oil. I got a top up literally within two hours. Could a cell be ‘gone’ like that?

Also is there a way of verifying the cell? Ie take it out and clean it or something?

John.G

Cona wrote: »

With regards to the cell being gone...what is the photocells function in the boiler from day to day?

Reason I ask is that the boiler was working perfectly this morning, then ran out of oil. I got a top up literally within two hours. Could a cell be ‘gone’ like that?

Also is there a way of verifying the cell? Ie take it out and clean it or something?

The purpose of the cell is to ensure that the oil is actually burning and not just spraying into the combustion space creating a very dangerous condition.
The sequence is when the burner gets a signal to start, the fan does a (pre) purge for 12 secs, the igniter (spark) and the oil pump solenoid open at the same time, after a further 5 secs the igniter shuts off, if the cell doesn't detect a flame within this 5 sec period then the burner shuts down and has to be reset for a further attempt or if the flame goes out while running (ie lack of oil) then the burner trips off as well.

I don't know how easy/difficult it is to remove the photo cell on your burner, on my one one had to remove the control box but I must say that in 14 years
of operation that my burner has never cut out and the photcell is always spotlessely clean.

On the newer, low emission burners, (maybe your one) a post purge also takes place when the burner shuts down normally so even though very unlikely I suppose its possible that the burner controls, for some reason, are stuck in this mode.

I would suggest getting some one to have a look at your problem.

Wearb

John.G wrote: »

The purpose of the cell is to ensure that the oil is actually burning and not just spraying into the combustion space creating a very dangerous condition.
The sequence is when the burner gets a signal to start, the fan does a (pre) purge for 12 secs, the igniter (spark) and the oil pump solenoid open at the same time, after a further 5 secs the igniter shuts off, if the cell doesn't detect a flame within this 5 sec period then the burner shuts down and has to be reset for a further attempt or if the flame goes out while running (ie lack of oil) then the burner trips off as well.

I don't know how easy/difficult it is to remove the photo cell on your burner, on my one one had to remove the control box but I must say that in 14 years
of operation that my burner has never cut out and the photcell is always spotlessely clean.

On the newer, low emission burners, (maybe your one) a post purge also takes place when the burner shuts down normally so even though very unlikely I suppose its possible that the burner controls, for some reason, are stuck in this mode.

I would suggest getting some one to have a look at your problem.

If you are competent enough, you can verify if it's the cell by disconnecting its wiring from control box. Then press reset, if boiler fires up for a few seconds and then locks out, it's a faulty cell. If this advice sounds complicated, then get in a professional and perhaps have it serviced also.

jimf

as wearb says above but only if your competent

might be no harm to kill the power to boiler before you start