Worcester boiler issue

[Tomswan]

First of all, I am not going to try to fix this myself unless it is very simple, but I would like to be able to talk sense to a heating engineer when I can get hold of one.

I had a plumber out to fix my Worcester Heatslave Combi boiler before Christmas. He seemed to have done it. The boiler ran for a little over 24 hours then went again.

He reported back to the person who was here to meet him that the motor and fan were stuck, that he had freed them up as best he could, but that they might need replacing at some stage.

Of course I have contacted him, but he is signalling lack of interest. He is under impression it is the same problem as before.

However, before he came out the boiler was totally conked out. This time the burner fires and I get a few seconds worth of action before I get the error code signalling burner lockout.

I have checked the oil feed from the tank and there is no air or blockage in the line in the feed outside the boiler. I have undone the bleed screw on the burner and got a trickle of oil, so it looks to me as if there is no air in that line.

I have bled all the radiators and found air in one of the them which, it seems, caused pressure to drop. However, even with the radiators bled and the pressure holding steady at around 1.5 bar I am still getting burner lockout.

So my question is: if the boiler is running for a few seconds before cutting out with burner lockout is this likely to be the same issue with the motor and fan, or something else? And if something else, any ideas what it might be?

What I am trying to do is avoid repeated visits which will quickly start to add up to a significant chunk of the cost of a new boiler.

Thanks in advance for any advice.

 

[muggles]

Needs someone there to diagnose really. Sounds like the photocell isn't seeing the flame, but if the motor is binding it's possible that the boiler has sooted up and blocked the cell, or the cell isn't seeing the flame for some other reason. Alternatively, it could be a faulty photocell, but given the fault history I'd be looking at motor and pump first

 

[Tomswan]

Thanks Andrew. I've been googling a fair bit to try to narrow it down, and came across the issue of photocell not seeing flame. Since there was a lot of gunk build up (I think in the fan) because of lack of proper servicing (previous elderly owner had been paying £140 for 30 mins annual 'service') I did wonder if the photocell had been gunged over. However, I have no reason to believe the guy who came wouldn't have noted that and cleaned it up at the time.

It is a Riello 2.2 burner and after googling a bit it looks as if replacing the motor and fan is not too difficult, or expensive. I still don't fancy it much myself. If it was middle of summer and I wasn't freezing I might be tempted but last thing I want to do in this weather is start taking apart things I cannot put back together.

 

[Terrywookfit]

If the oil pump was seized he should have known that it would not last.
It is pointless bleeding rads etc as this will make no difference.
So you are saying that the motor runs and pre purges and a flame is established for a few seconds prior to lockout. ??

 

[Tomswan]

Yes, that's it. 855 9F I think. Its same as I had once before when oil ran too low and I had to get air out of the fuel line. After I did that before I was up and running again. But this time no. I bled the radiators because the pressure was dropping off and I thought that might be causing the lock out. But not that.

In his defence he did say straight off that the motor might not last. I was not there but had someone let him in to do the work, so `I got second hand report. But he wasn't trying to claim he had fixed it permanently, just got it running again for a while.
Since the failure is different, in that I am getting ignition for few seconds before lockout I was wondering if it might be different cause.

 

[Terrywookfit]

Have you cleaned the photo cell.

 

[Terrywookfit]

I'm not familiar with fault codes. I prefer to check what is happening ! The RDB has changed very little over the years.

 

[oilhead]

It really needs a visit to be sure. If pump is now free, it will not stop the motor, but may not be producing a spray, so you get lockout. It may also just be a faulty photocell.

 

[Tomswan]

Have you cleaned the photo cell.

No. I will do so in the morning. Thanks. Looks simple enough to do.

 

[Tomswan]

It really needs a visit to be sure. If pump is now free, it will not stop the motor, but may not be producing a spray, so you get lockout. It may also just be a faulty photocell.

He changed the nozzle. Since that's another suggestion for cleaning photocell I will check it for sure. Thanks again.