Baxi HE133+ makes very loud banging noise and then red LED comes on

[paltibine]

I went to do the washing up and turned the hot tap on and heard a loud ban from the boiler! I turned the tap off straight away but the boiler kept on making the banging noises so I turned it off at the mains. Waited 5 mins and turned it back on, turned the tap on and it starts banging again and carries on banging after the tap is turned off.
When I forced the heating on the pump sounded like it was starting normally then there was a pause and a few clicks (usual sort of relays clicking) then it starts banging again but after several loud bangs the red LED with a symbol of a flame with a line through it lights up like it has overheated.

I did have a look and there are several threads about banging pipes and a few about banging boilers but most of these sounded like more ongoing issues where this has come on suddenly and stops the system dead!

It appears that the pump is running fine but what should I check next?

I don't know if it's significant but 2 weeks or so ago I had to pump up the pressure vessel as the pressure was going too high. It seemed fine after I got the bike pump on it and there didn't seem to water in the air side of the vessel and it has been fine since then till tonight!

Thanks in advance for your help!

 

[terryplumb]

There are a number of issues that can cause the symptoms you describe and you would be well advised to call in a professional ,as some are related to combustion and are not within the scope of diy repair.

 

[paltibine]

Thanks for the reply Terry!
That sounds reasonable in this case. The bangs sound just like explosions in the combustion chamber so I will make some calls.

I hope the weather isn't too cold for the next couple of days! These combi boilers leave you a bit exposed when they break down don't they!

 

[durhamplumber]

Thanks for the reply Terry!
That sounds reasonable in this case. The bangs sound just like explosions in the combustion chamber so I will make some calls.

I hope the weather isn't too cold for the next couple of days! These combi boilers leave you a bit exposed when they break down don't they!

Put your jumper on

 

[paltibine]

Well the heating engineer came round today and diagnosed that the burner assembly had completely disintegrated and the ignition and flame detection electrodes were shot. Just awaiting the parts to come and he will fix it.
Quite an expensive job!
Fingers crossed the parts don't take too long to come the temperature in the house has been falling slowly and steadily since Friday and is now down to 13C.

 

[paltibine]

Parts fitted now and all warm again!

The engineer said I should get the parts myself after listing the items I needed as he said it would be cheaper and quicker to get them online than for him to order them. He showed me the prices he would have charged and I saved about £150 by getting brand new parts off ebay and paying for next day delivery.