Worcester CBi heat exchanger melting, boiler 6 months old!

[Circuit]

Worcester 14/19 CBi heat exchanger melting, boiler 6 months old!

On the CBI it has 2 stainless steel heat exchanger baffles with "fingers" that glow red hot right next to the cast iron HE fins.

A groove has developed on the HE fins by the lower set of baffle fingers. On some fins the groove appears to be a crack. Also the bafffle has distorted slighlty due to the heat and pushed into the combustion cover insulation.

It seems that the life of this boiler is only going to be a few years at this rate.

Any thoughts from the chaps who have installed this model??

 

[COG]

A . is the boiler gas pressures ok as per the book B . is the corect flue restricter ring fitted C . is the flue of the corect size takeing into acount bend etc (not to long ) D .does it terminate ok

 

[Circuit]

The boiler was inspected by 2 worcester bods yesterday, and it is working normaly with 6.5% CO2, 9.5% O2 and output of 18KW. (it is a 14/19 CBi). The engineer said he had seen worse baffle distortion on other CBis, and photos were taken by them of the melted HE to be sent to R&D.

The design of this HE is flawed since the baffle creates hot spots around the lowest row of baffle "fingers" allowing cracks to develop that then erode in the heat.

It would be interesting to know how other CBi HE have faired that are more than a year or 2 old. I asume the CBi HE design has been around for a few years?

 

[htgeng]

please define what you mean by 'melting'.

 

[namsag]

Circuit did you tell them how you altered this boiler. as you told everyone on the plumbing pages web site when you installed it or did you keep it a secret.

 

[Circuit]

Well what folk post on forums and what they do are quite different as you well know. The forums are supposed to provide some entertainment for the readers and get them ranting, and they tended to fall for it


The only modification as such I performed was to use coach screws instead of flimsy screws to hold the thing to the wall.

And talking about Plumbing Pages, where are they now?

Oh and "melting" = cast iron on the HE fins disappearing where a hot spot exists created by the SS baffle fingers.

Please note this thread is only intended for people who have experience of the CBi in service.

 

[ChrisR]

Well what folk post on forums and what they do are quite different .
...provide some entertainment ...

Please note this thread is only intended for people who have experience of the CBi in service.

No, most people are honest and use forums with integrity. YOU may make judgements on who should read your "contributions" but you are irrelevant in that. I hope as many as possible will read and realise how you have got yourself into trouble. I for one could, but will not, advise you.

How are we expected to take you seriously if you think it's entertaining to prat about with forums and the people who spend their time trying to help, as well as pratting about with your boiler?

For other readers - Circuit is not trained or judged competent in gas, installed his own boiler and told us all how he made modifications to make it better.

 

[Circuit]

ChrisR not on this forum. I have made plenty of posts on a variety of topics on a different forum, as I am entitled to do, I have never advised anyone to do anything as far as can recall since I feel "helping" people on a forum is a wasteful use of a person's time etc. Exchanging information and putting forward points of view are generally what forums are for in practice. Posting that someone has been "prating" around is offensive and not allowed under the T&C of this forum

And no I have not got my self in to trouble as you put it. The boiler has never been modified as you imply and as I posted before, the engineer who called said and I quote (when referring to the heat distortion on the HE baffles "of all the CBIs I have seen this is in the best condition".

Chris if you and other addicts from Plumbingpages.com continue to behave in this way and post in this way and off topic, I will alert the moderator.

 

[PEDANTICVINDICTIVEMAN]

OOOOoooooooooooooooooooooooooooooohhhhhhhhhhhhhhhhh, scratch your eyes out after I've hit you with me handbag

 

[Circuit]

Thats more like it, a little bit of humour

 

[namsag]

Circuit .Good to see you are man enough to admit to being a liar.

 

[Circuit]

Well a "liar" is putting it a far too strongly, more like telling a yarn.

It has been said that it is a very unwise person who takes on face value anything one hears via the Internet, and also an unwise person who takes on face value anything said by tradesmen and salesmen, as we repeatedly find from other poor soul's posts.

I am sure that no CORGI bod would ever tell fibs to their customers, even if they profited from the deceit?

 

[bripl]

cbi boilers have a reasonable heat exchanger with only one fault o rings on both sides have been known to let go you must change all 4.the problem you have sounds like1/burner pressure,2/burner bar not having proper spread/flame picture.
finger baffle is prone to distorstion due to thickness of material.only other prob iam aware of is aps/ignition lockout which worc do sort out under warrenty

 

[Circuit]

The boiler has always been run with a burner pressure set for a 18kW output, I therefore hope that in 12 months time the HE and baffles will not have worsened.