Worcester 28CDi RSF Combi-Boiler (gas) problem......please help !

[Pete@]

Hi,
I have a Worcester 28CDi RSF Combi-Boiler (gas) which I have a problem with.
I had a plumber come to look at it yesterday and he told me that I should replace the boiler as it would cost more than it is worth to fix it.
The plumber is not someone I know, and fair enough, if it needs a new boiler then that is what we will have to do, but I'd like to a second guess on this before I spend money that I can't really afford.

I am an experienced mechanical engineer and understand that things go wrong, perhaps I should just stop rambling tell you about the problem and ask for your opinion !?.

For a little while now (since around xmas), the central heating side of our boiler has been playing up. It runs for around 5 to 10 minutes and then gives a boiler lockout error (red light flashing).
If I reset the error, the ignition system will try to light (there is a good consistent spark), but it fails to light (almost as if there is no gas coming through) and the lockout error continues.

The hot water side of the system is fine, although it does sometimes cut out with the same type of issue.

It is almost as if the system is overheating and shutting itself down.
If I isolate the system for a while, (until it has cooled ?), I get the same symptoms over again (can't get past those first 5 to 10 minutes).
The radiators become warm, but not hot (no blockage or water pump issue ?).

The plumber says that it is a faulty heat exchanger, and would cost around four hundred to replace, ok I've looked at the cost of the spares and can accept this.

Does this sound right ?, is there something I can try (reasonable electrical and mechanical) just to make sure the problem is the heat exchanger ?.

I don't want to waste more money getting a second plumber in if he is just going to confirm the original diagnosis.

Gents, I would really appreciate some sound advice.

Thanks
Pete

 

[capitanpugwash]

Hi Pete,

I am not a plumber but had exactly the same issue recently with an Ideal which is only 3.5 years old. The heat exchanger started leaking and the plumber turned off the system due to the loss of pressure and leak internally. He told me what part to get and would slot me in for labour when I found it. I could find massive difference in part prices, but the cheaper ones came with a cost - 2-3 weeks delivery! The local plumbers merchant did a lot of calling round and got one in 3 days from Ideal directly and couriered it but the cost of the part alone was £300. The plumber who I've used a lot suggested it may be better to fit a new boiler which would cost £8-900 for the boiler and £6-800 labour. It feels wrong to have to throw away a 3 year old boiler for a single mechanical fault. The heat exchanger arrived after 3 days and the plumber fitted it the next day for £100. All in £400. A painful sting just before Xmas when it was snowing but cheaper than a new boiler by a long way. If you've got heating at the moment and can manage to hunt around for a cheaper heat exchanger, I'm guessing the labour will be £100 or so.

It's a shame that boilers have got to a point where they seem to last only a few years.

Best of luck....