Scaled Heat Exchanger? Bad enough to cause problem?

[MAXEON]

Doesn't look scaled to me. Much more likely to have been controls side.

Having looked at the MIs for the old boiler and the flowchart for the symptoms (intermittent DHW fault) and being suprised at how unblocked the HEX looked to me, I suspect the real fault may have been a faulty thermistor or temp sensor or flow sensor?

 

[MAXEON]

Doesn't look scaled to me. Much more likely to have been controls side.

That is my feeling too - my eyes are telling me it was not the hex.

 

[MAXEON]

Craig’s comments are spot on.

That does not look like a set of tubes that have been used in a hard water area - do you know the hardness of the water feeding your boiler?

Slightly hard according to Severn Trent Water and no lime on taps/showerhead.

 

[Harvest Fields]

Not read all posts but. You can always get a second opinion.

 

[chris watkins]

Having looked at the MIs for the old boiler and the flowchart for the symptoms (intermittent DHW fault) and being suprised at how unblocked the HEX looked to me, I suspect the real fault may have been a faulty thermistor or temp sensor or flow sensor?

Your problems was relying on a large company - have a read of my post in "Long boiler warranties? Worth it? "

(Shamelessly plugging his own posting )