Baxi Duo Tec 28 issue

[Peter Goble]

I did it my self as the engineer had the decency to tell me he couldnt get hold of a pump / circulator for less than £350 plus labour so it would be cheaper to get Baxi to come out and fix it. Got a "New" un-boxed pump from Ebay and fitted it myself. This engineer came out to my house and looked at the boiler to Diagnose the problem yet all of you Keyboard engineers who have not looked at my boiler have slagged him off doubted his ability and made numerous statements stating he is wrong. Really!!!!!!

 

[ianmcd]

Both you and him are wrong, if he actually exists, you have an expansion problem, absolutely nothing to do with the circulator (what you call the pump )

 

[Peter Goble]

The symptoms the Engineer explained are as follows, which may differ from my explanation:
When the burner ignites either from hot water or heating demand then the boiler starts to "kettle" excessively.

by removing the old circulator and putting a new one in it has stopped the problem, therefore the problem was the circulator.

 

[boolie]

Ketting can be caused by a failing pump.

My amateur opinion is that you had multiple problems a blockage in the system, a failing pump and possibly the DV was letting by. Some where along the line of replacing the various parts (DV and pump) and draining the boiler either removed the blockage or moved it on

Blockages are caused by a dirty system. So you may well need to remedy that to avoid future headache