Worcester Boilers Eating PCB's

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Dave Plowman (News)" saying something like:

[Dave Plowman (News)]

Perhaps you'd refer me to a maker's service instruction where it says bearing shells must be changed as part of a routine service?

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Dave Plowman (News)" saying something like:

Perhaps you'd like to go and rummage in a manual library of forty years ago?

[Dave Plowman (News)]

Sigh. I've already mentioned I have a factory workshop manual for the Sprite/Midget, and there's absolutely no mention of routine bearing shell changes. Nor have I ever read it in other manuals from that sort of time.

Of course it's quite possible some very expensive esoteric sports car maker did. In the same way as some Ferraris have to have the engine removed to change a cam belt...

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Dave Plowman (News)" saying something like:

Just because it's outside of your experience doesn't make it untrue. It is/was a fact that many engines of that era and before needed and were recommended to have a re-shell at or around 30 to 50 thousand miles. BT,DT,replaced the shells. For example, the Essex lump needed shells as a sensible precautionary measure at about 50K, with the crank being fine. So, for you to spout on about simply because you haven't read it, it's not true, is utter bollocks.

[Dave Plowman (News)]

I'm talking about the Midget, etc.

Ok. Give me a maker's reference. Because I'm not just taking your word for it. Even Rolls Royce did not recommend bearing shell changes as a routine

- even with their far more extensive maintenance program than most. And I had the factory manuals for both the 6 cylinder and V-8 models from the '60s.

My experience is based around these cars when they were current. When they become 'classics', all sorts of bollocks gets spouted by loving owners.

And since most engines of this era wore out fairly uniformly, why just the emphasis on big end shells? When big ends got worn, so would the mains. And bores. Of course a dedicated bodger might hope to extend the life by replacing the easy bits, but when such wear got beyond a certain point a full overhaul was needed. Which involved a crank grind and re-bore. As well as much else.

[The Other Mike]

previously heard anything about them being seeded and promoted by low temperatures.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Dave Plowman (News)" saying something like:

Those got replaced, too.

Not necessarily. Is it so hard to understand? Some engines only needed shells and the rest of the lump was fine and good to go for another 50K.

[Dave Plowman (News)]

Yes. Because I've never seen this in a maker's schedule.

Seems like strange engine design. Why have bores and pistons which outlast the crank bearings? If anything, it was usually the other way round. An engine started using oil long before the bearings failed.

[N_Cook]

Tin whiskers are a different process, but their growth also supressed by the presence of lead.

[Mark]

I guess that maintenance required at 30K-50K would have been irrelevant for most since the bodywork would have rotted away by then and the car would be in the scrapyard.

[Tony]

Ok. I take it none of you know anything about the boiler circuit board poor reliability then? My boiler goes through them about 1 every 18 months. They are about 200 quid to replace. Tried a new one but no more reliable than the 40 quid ones from allspares.com

I also had a fan failure but fixed that with some WD40. If it doesn't spin freely enough it fails the pressure test and you get the flashing light syndrome.

Tony

[Tim+]

Dunno. Why don't you try asking instead of replying to a 5 year old message and opening with an insult?

I smell troll...

Tim

[Martin Brown]

If the boiler circuit board is failing that often then something else like condensation and corrosion is killing it. Mine has lasted forever.

The controller mains relays do sometimes got bad but they are socketed and easily swapped although for older boards are becoming quite rare. RapidOnline still had them last time I looked.

Flame sensor sooted up or bad connection is the most common fault.

I wish modern boilers were as robust as the old Worcesters. My 15/19 dates from the 1970's when machine readable space age fonts were trendy.

New condensing boilers seem to be much more fickle and inclined to stop working at the slightest provocation - usually on the coldest days due to their condensate pipe freezing up or something equally dumb. Based on neighbours experiences. We are all on oil fired boilers here.

[Tim+]

Our Vaillant boiler started eating circuit boards. Turned out to be due to a very small weep from a badly sited automatic bleed valve above the boiler that was dripping down into the casing.

Tim

[Tony]

I wasn't aware that I was insulting anyone. I followed the thread about boilers and it turned into a long discussion about cars.

I was simply passing on my experience with this boiler in case it helped anyone.

I have now fixed it and I have learnt a lot about the boiler which may be able to help others with as this boiler has been so unreliable I have had t learn a lot about it.

This is not to lessen the experience of professionals but when you are skint you need to do stuff yourself - hence forums like this.

[Tony]

Thanks Martin.

You are probably right in that something is killing the boards. However, each fault appears to be different. This time I changed the board and it went through its sequence up to lighting. The spark was happening but no gas. The voltage was being applied to the gas valve solenoids but no gas so looked like a faulty gas valve. Resistance of coils was 450 ohms for one and 150 ohms for the other. I don't know what the resistance should be, hence a visit to a forum such as this, but it sounds suspiciously low and I would have expected them both to be the same. I heated the gas valve (as it had got very cold with the heating being off) and it started to work. I assume the solenoids may have shorted turns and will probably kill the board eventually but it is working at the moment so i'll see if I get through winter then possibly change the boiler as this is now about 15 years old and has been a loot of trouble.

[Tim+]

Well you opened by saying that no one here knew anything about boiler circuit board reliability. Had you offered that opinion when the thread was current, it would have been topical and possibly correct *at that time*. That time was five years ago though.

Given that the readership changes over time, why presume that still to be the case? It may well be, but it's insulting to suggest it straight off the bat without evidence.

That finished a very long time ago.

Tim

[Tim+]

If it's anything like one of our old boilers one solenoid is energised by a thermocouple whilst the other is mains powered so I wouldn't expect them to have the same resistance.

Tim

[Tony]

Tim,

the gas valve is 87161056540 with 2 solenoids at 24V RA 5.5VA

The board powers the solenoids at 24 volts and they are independent of each other and have separate feeds from the board so I suspect at least one of the coils has overheated and has some shorted turns which reduces the resistance and of course also results in less pulling power but heavier current demand on the board so I don't expect it to last too long - just hoping it lasts until the winter is over.

I'll probably get a new boiler - not a Worcester Bosch though. Any recommendations for a 28kW combi?

Tony