Boiler: Ideal Icos HE24 display off and no hot water no heat

[gas4you]

Well, what can we say. You came on here for advice, I said call Ideal at £210 fixed price, SDG said BG at £170 ish.

You chose not to take the advice that was given I even warned you that at local would be at least £100 dearer.

Your choice, your money

 

[cortinamaddave]

Please Help
My uncle has the ideal he24 there is no heating or hot water and the display does'nt work after reading the previous posts we've tried the black fuse on the orange pcb to no joy. when you turn the on off switch on the display panel the orange pcb clicks but no heating hot water and the display stays dead and next to the mains fuse on the wall by the boiler there is a white honeywell box with a little green light and little flashing red light underneath when the boiler was working there was only the green light on the honeywell box showing ,he cant afford to have any engineers out as they are struggling for money and charities have told them that they need the p60 in april for a grant so cant help till then. is it the display panel or orange pcb? any help or advice would be gratefully received

 

[diverdee]

Need u to answer couple of questions like is it a combi or heat only or if u want just ring me 07850762290 David

 

[cortinamaddave]

ok thankyou my uncle will phone you now thanks again

 

[Poolio19]

Cortina mad Dave,

I had this very same problem. One morning HE24 was dead, no display no nothing.
Checked the fuses all fine.
From an internet scour and a chat with the bloke who serviced my boiler and fitted some radiators - it sounded like my PCB was goosed.

I wandered onto eBay bought a refurbished one (£55) and fitted it myself.
It's really quite easy.

Took the old PCB apart and noticed the big blue component in the middle looked fried... sticker had melted.
https://onedrive.live.com/redir?res...authkey=!ACFdMsvNPLQ8seg&v=3&ithint=photo,jpg

So had to look inside the "new" one which looked fine...
https://onedrive.live.com/redir?res...authkey=!ABPoTlTSy-GX9W0&v=3&ithint=photo,jpg

Before I removed the old PCB I took a few snaps of the wiring to make sure I reconnected the same as I disconnected it.
https://onedrive.live.com/redir?res...authkey=!ACwvpFZniHrwDtc&v=3&ithint=photo,jpg

Needless to say if you're not confident doing any of the foregoing I'd get a man in, but it's really not very complicated at all.

JP

 

[robmort]

The reason the PCB often fails is that the contacts of the spark ignition are burnt away and too wide apart, causing the PCB to work too hard in generating spark power.
So you should always check the spark plug to avoid this happening again.

Rob

 

[Agile]

That's not my experience!

Usually water has leaked onto the back to back connection behind the display PCB and overloaded the main PCB and caused the transformer to overheat and blow its thermal fuse in the winding.

Tony

 

[robmort]

Usually water has leaked onto the back to back connection......

Tony

Well in that case it'd be pretty obvious from the stains etc......

But often there's no obvious reason, so I suggest the above check.

 

[DP]

Robmort, the electrode gap has nothing to do with ht generation. Designated spark voltage is function of spark generator. At ignition sequence voltage goes to spark generator and ht comes out regardless of what state the electrodes are. If the spark cannot jump the gap on the electrodes, boiler shuts down- it does NOT keep going ot builds up to a higher voltage to get Frankenstein out of bed

 

[robmort]

Robmort, the electrode gap has nothing to do with ht generation. Designated spark voltage is function of spark generator. At ignition sequence voltage goes to spark generator and ht comes out regardless of what state the electrodes are. If the spark cannot jump the gap on the electrodes.....

As in all electronic ignition systems (e.g. for cars), the maximum HT voltage generated is limited by the HT coil and its input voltage from the PCB. The spark jumps the gap of the HT electrodes when the HT voltage reaches a value it needs. At a normal spark gap the spark is created well before the max. is reached on the HT output.

As the gap widens, the spark creation voltage increases until it reaches the max. HT voltage after which the spark is not created. But until this point (which is usually a gap several times wider than normal) the power (i.e. current) needed from the PCB to the HT coil increases with the spark voltage (P=I*V) and this higher power often causes overheating in the PCB generator, because it is several times higher than normal.

Rob

 

[DP]

Rob, what you say, I am sure is correct for car ignition systems

The spark generation in boiler is often achieved by SCR switching mains AC voltage. Boiler in question does not even have a spark generator on the PCB- it is mounted remotely and is supplied with 240 volts AC from a relay a circuit the transformer plays no part in other than provide rectified DC voltage to operate the ralay (which stays operated for dur ation of boiler operation so is not stressed). The transformer is there to provide low voltage to power chips and drive circuits. There is further protection with three board mounted fuses and one fuse that is replaceable

If what you say is true in this case, it is the remote transformer that would be cooked, not th blue 'thing' on the PCB

May I further add, gap on electodes does enlarge. There is no doubt about that. Boiler would start locking out if gap gets too big or would 'backfire' upon ignition - crude analogy

 

[Agile]

I have never heard such totally wrong speculation about electronics before.

A boiler spark gap is typically about 4 mm and whilst they start a spark at about 10 kV they do not widen by "many times" that size. There is just not enough space in the boiler.

Most spark generator circuits produce about 14 kv which will create a spark across about 8 mm.

Tony

 

[robmort]

Of course if you misquote me you can make up anything.

I said "several" times.

The gap is specified as 3.5mm.

You should have seen the electrodes in my boiler; the gap was 8-9mm.

This had caused arcing outside the spark plug to the case etc. before the PCB failed.