excessive sludge and corrosion

[SJB060685]

But could the failure of any internal part result in contamination of the water?

The formation of black or red sludge in the system is caused by oxygen in the water reacting with iron content in radiators. Theres a lot about the science of it I could rattle off but basically its down to the oxygen content within the water. Any oxygen added to the system when filling has usually depleted to levels not sufficient for prolonged corrosion within two to three months.
If you have large amounts of sludge this is a sign of air being drawn into the system, this can be caused by a few ways.

 

[alb000000]

The formation of black or red sludge in the system is caused by oxygen in the water reacting with iron content in radiators. Theres a lot about the science of it I could rattle off but basically its down to the oxygen content within the water. Any oxygen added to the system when filling has usually depleted to levels not sufficient for prolonged corrosion within two to three months.
If you have large amounts of sludge this is a sign of air being drawn into the system, this can be caused by a few ways.

the bottom line is really , should this damage be covered by my warranty and worth fighting for it , or would it be an external cause that has caused the damage .
I wonder who would need to prove this ,

 

[Scott_D]

I don’t think you have much chance.
If they are saying that sludge from your existing heating system has damaged the boiler it won’t be covered under warranty.

 

[alb000000]

I don’t think you have much chance.
If they are saying that sludge from your existing heating system has damaged the boiler it won’t be covered under warranty.

Sorry but not sure I understand, what does sludge from my system mean? If on last service there was no sludge and right after the service the entire system was powerflushed, where did the sludge appeared from? Would it not be new sludge that was created after the flush?

 

[SJB060685]

the bottom line is really , should this damage be covered by my warranty and worth fighting for it , or would it be an external cause that has caused the damage .
I wonder who would need to prove this ,

As Scott says above, if sludge has caused damage to the system then its rare that a boiler manufacturer will honor the warranty, in fact most likely impossible. Its one of the reasons systems should be flushed on installation of a new boiler.

 

[alb000000]

As Scott says above, if sludge has caused damage to the system then its rare that a boiler manufacturer will honor the warranty, in fact most likely impossible. Its one of the reasons systems should be flushed on installation of a new boiler.

I see, however I am not convinced that this was the cause of the damage. on the engineers report the cause of damage was stated as blocked condensed pipe. They never actually saw it blocked but they suggested that this would have caused the damage. They told me at the time the blockage could be the result of a frozen pipe. I am very dubious of this claim since A) it was mid July and never had prior problems B)that winter had been very mild C) Vaillant tech told me that a shutoff valve would prevent damage in case of a blockage
the issue of sludge only came later at a second inspection when they said it wasn't economical to repair it due the state of boiler

 

[SJB060685]

Sludge is caused by one thing, air ingress. The problems you mention above are not related to sludge, apart from possibly the heat exchanger. It seems to me Vaillant are doing whatever they can to avoid paying out. I cant advise further as I'm not gas qualified. God I'm glad I only worked with oil fired appliances.

 

[Scott_D]

Can you post some pictures of your boiler and the condensate pipe?
Any pictures of the paperwork they issued you?
Have you got a magnetic filter fitted?
An incorrectly terminated condensate can block or backup flooding the boiler eg if it goes into guttering.
All modern boilers are easily damaged by sludge from radiators.