Sime Superior Cycling problem

[bmcutts]

We have a Sime Superior 50 boiler which is having problems starting up.

The fan runs for a few seconds then stops, restarts, stops etc for around a minute before the pilot light ignites the main burners.

The problem has been occurring for a couple of weeks and is steadily getting worse. Does it sound like an electronic fault?

Any ideas, thanks

Brian

 

[Agile]

I cannot come to any conclusion from your description.

It would probably be APS, PCB, venturi, ignition/sensing electrodes or gas valve settings.

Mostly jobs for a CORGI engineeer.

Amusing all these superlative names given to cheaper brands of boiler, Ultimate, Superior, Ultra etc.

Tony

 

[bmcutts]

I dont' think it's the ignition or associated sensing electrodes since it's not getting as far through the process as firing up the pilot. The problem I'm havin g is finding a recommended CORGI engineer who knows about this boiler. Two I have contacted so far are unable to help.

Brian

 

[croydoncorgi]

If you mean the Superior 50ci, it looks like a bog-standard cast-iron boiler with virtually zero complexity! Can't see why Corgis take 3 steps smartly backwards!


PS
You forgot 'Sup**ma' ,Tony!

 

[Agile]

I had forgotten what the "Suprima" word originally meant !!!

That boiler could not be further from the original meaning!

 

[bmcutts]

I must admit that it doesn't seem to be a very complicated unit compared with others. Maybe the reason that my local CORGI engineers are not interested is that it's not chalenging enough

Seriously though... it it possible that it's failing to sense that the fan is running due to a faulty relay or sense switch (seeing as it does fire up after a number of attempts which is steadily increasing - average 20 tries now)?

 

[bmcutts]

Well having spoken with Sime it appears that the boiler is a good old fashioned Potterton Profile50.

I've done some more digging and the air pressure switch seems to be OK. I also tried manually blowing gently down the sense tube and all that happens is that the fan on the system continues to run but there is still no light up. I'm beginning to think that it's the electronics and I've removed the unit and checked for dry solder joints. In fact I resoldered them all.

Still no joy so now I'm wondering if maybe one of the two relays or a capacity has gone leaky. I'm blowed if I'm spending £140 plus VAT on a board with around £10 of bog standard components on it.

Anybody got any helpful ideas?

 

[bmcutts]

As a follow up to my last post after a trip to Maplins and replacing 3 electrolytic capacitors and 3 transistors for the grand total of £0.71...

Problem solved!!!