Ideal ICOS HE18 - problems todate..

[jef]

Hello All,

wonder if you could help. our boiler is two yrs old

We keep periodically getting an LF error which from the manual means its a flame error.

We had a similar problem when it was initially installed but this was accompanied by a bubbling sound and "banging" when it did eventually light - this was diagnosed as a blocked condensate trap and problem solved.

We now get the same LF error, but it isnt consistent - ie. we can go a day fine, then wake up in the morning freezing cold as the heating hasnt come on in the morning due to the error. I have managed to catch the problem a couple of times - namely you hear the boiler try to work 3 times and then up comes the LF error. Upon resetting once or twice via the reset button it will generally pick up and work...
I would say the problem happens more when the heating system is still "warm" from the last run (oh and on cold days !!!)....

The fan comes on, the gas valve opens (you can smell the gas in the flu when it doesnt light) and you can even here the electorde clicking...

Thankfully we have a service contract - so far they have been out numerous times and have fitted - electrodes, PCB, gas valve and have also had transco come and fit a new regulator on the gas supply. Beginning to feel sorry for the British gas engineers as they are now scratching there heads trying to work this one out... (oh and the condensate runs clear and fine!)

Next visit we are due a new spark generator and leads...

If anyone from ideal or a.n.other is around who can help with any ideas please let me know !!

Thanks

James

 

[shambolic]

Could be a gas inlet pressure problem too. Why have bg not asked for a manufacturers visit as under warranty?

 

[Agile]

I am also dealing with one of this range with this intermittent fault!

Unfortunately I dont have the advantage of an unlimited range of free spare parts to change and in any case thats against my nature as I like to diagnose the fault and not just change parts!

In my case its not helped because on THREE visits and about 120 startups its never failed. The tenants say it fails 10 minutes after I leave although the husband says it runs for 1-2 hours and its the wife who says it always stops 10 minutes after I go.

I cannot offer any suggestions for the time being but I can say that no one seems to change the spark generator and that would be in my first line of suspects but perhaps it is very reliable and never fails unlike the gas valve or PCB.

In your case you have not said if the flame actually lights and then goes out because its not been detected. You imply that it does not light at all which would indicate:-

Spark generator ( although you say you can hear it--- but that could be sparking in the wrong place too! )
Spark electrodes
Gas valve
Gas mixture
PCB not turning on the gas valve at the same time as the spark ( although thats unlikely )

In my case the gas supply is undersized but still gives 19 mB on start up power and falls to 16.5 mB on full power. However, its run fine for the last two years so I am not expecting it to be the cause and in any case its constantly undersized which would not explain the intermittent nature of the fault.

Tony

 

[jef]

hi,

they have checked the gas inlet pressure and its fine as is the gas mixture (albeit that is checked when its all happy and running!).

The BG chap also checked the electrode distances and these were out and slightly bent - hence replaced and fitted correctly. (1st problem visit)

2nd visit ended in replacement of the PCB and gas valve (wasnt sure what to replace!)

lets hope the spark generator change on weds sorts it ! that will at least cover all of the mentioned problems from Agile (thanks by the way!).

The BG chap did mention that these boiler ICOS HC models have lots of problems and have been discontinued and redesigned, then recontinued since they were brought out.... so for now I will be keeping the British Gas contract going !

 

[gas4you]

I had one of these about 3 weeks ago that kept giving the L:F code without firing up at all.

For some reason it was the flame detection electrode faulty. I haven't a clue why this stopped it attempting to fire, but it did

 

[idealnumber1]

try the detection lead on the left

 

[Agile]

try the detection lead on the left

Can you sugest why anything to do with the detection lead or electrode should cause it to fail to light up as Dave describes?

Tony

 

[gas4you]

I'd like to know as well Tony. To me this should only come into operation to detect whether the flame is there or not.

But then this is an Ideal boiler. Anything that could be illogical is going to be found on one of their products

Have you tried replacing this on your problem Icos Tony?

I always carry 2 spare ignition electrodes and flame detection electrodes on my van, as they are so common at causing problems

 

[Agile]

Many PCBs will prevent the ignition sequence proceeding if the detection electrode is shorted to earth. I dont know about that model though.

Its difficult to imagine how that could happen with the design of the Ideal electrode and lead.

At my landlord's request ( but not my specific advice ) I replaced both electrodes last Thursday. I emailed him on Friday to ask if it had solved the problem ( or not ) but have not as yet received any reply.

I had copied him the posting about the 13 visits by Ideal staff engineers and the boiler then being changed only to develop the same fault! I also said that replacing all the likely parts would come to about £600. That seemed to frighten him as he told me not to replace anything without his agreement!

He seemed to lose faith in me and was evidently talking to some other people and had been advised to change the electrodes. A fellow he had there on Wednesday could not replace the electrodes " because he had no experience of Ideal boilers" ! The Landlord then had to come back to me to get me to change them.

I would love to know if its cured the problem or not.

Tony

 

[snb]

have found that when you service these you often get the LF due to the ignition electrode being damp. to get round this and force it to fire i disconnect the detection probe.

Other day forgot to make sure it was not earthing on exchanger and it stopped it firing so my guess is that there is a fail safe just in case the exchanger was to fill with completely with water when they fail. (as they will!!)

 

[idealnumber1]

try the detection lead on the left

Can you sugest why anything to do with the detection lead or electrode should cause it to fail to light up as Dave describes?

Tony

at times the detection lead comes off the detection elctrode same as the black rubber lead when very hot,check condense trap, electrodes.spark assembly,leads, gas valve then pcb in this order and you will rectify the fault

 

[Agile]

at times the detection lead comes off the detection elctrode same as the black rubber lead when very hot,check condense trap, electrodes.spark assembly,leads, gas valve then pcb in this order and you will rectify the fault

But that would still allow it to fire up but then it would go out a few seconds later when flame detection was not established.

As I understand Dave, it was failing to turn on the gas as if the flame detection connection was shorted to earth.

I have never heard of a spark generator failing on this model so far. Are you saying they can be intermittent???

Tony

 

[idealnumber1]

spark assembly do fail on icos and isar thus resulting in explosive ignition,as for the dection lead the small clamp often opens up too wide

 

[gas4you]

On mine everything was in place and fitting correctly. For some reason the detection electrode had just packed up.

It then refused to allow the boiler to fire at all. Fitting a new one resolved it instantly

 

[jef]

all,

so far apart from a lot of failures on sunday last, we havnt seen any more - I did turn up the thermo on the boiler (from 3/4 to full) though after them but doubt that improved things. We have also had the spark generator and leads checked/changed weds so fingers crossed....

amazing - the most we had wrong with the baxi at the last place was the balloon/balance on the water pressure... these things are worse than PC's !