Baxi Duotec 40 hot water gone cold

[bobnlibby]

I posted earlier about our hot water cycling on and off but now its got worse 🙁

When a hot water tap is opened, water starts to flow, the boiler fires up and the boiler temp display goes up slowly to around 60 degrees, all as usual, and the water gets warm. Then, the boiler temp starts to rise very fast, there's a rattling noise from the boiler and at 95 degrees the burner cuts out. While this is happening the water goes cool again. This cycles for as long as the tap is on.

I've checked the central heating works normally, and the system pressure is normal but a fault code of E125 came up earlier, any ideas please ?

 

[SilentMike]

don't keep trying you could cause damage

when you said before that when he cleaned the heat exchanger and it worked briefly how long is that? did he use chemicals or just rinse it?

 

[Billy Bob Bob]

I posted earlier about our hot water cycling on and off but now its got worse 🙁

When a hot water tap is opened, water starts to flow, the boiler fires up and the boiler temp display goes up slowly to around 60 degrees, all as usual, and the water gets warm. Then, the boiler temp starts to rise very fast, there's a rattling noise from the boiler and at 95 degrees the burner cuts out. While this is happening the water goes cool again. This cycles for as long as the tap is on.

I've checked the central heating works normally, and the system pressure is normal but a fault code of E125 came up earlier, any ideas please ?

your plate heat exchanger is blocked stop using the boiler on hot water mode and call someone in

 

[bobnlibby]

don't keep trying you could cause damage

when you said before that when he cleaned the heat exchanger and it worked briefly how long is that? did he use chemicals or just rinse it?

I do not know to be honest as i was at work and my wife was at home and i have just repeated what he told me. It was only a week ago and it only worked for a couple of hours when he did that.

 

[bobnlibby]

Hi guys, thanks for your help with this. New plate heat exchanger now fitted and all is good ;-)