Vokera Combi boiler - Please help

[allallyouyou]

Hi there, this is my first posting so hope it goes well

I have a Vokera comi boiler and am experiencing a slight problem with it.

[Hot Water] When i turn the temperature above half way on the control, the boiler reaches approx 50 degrees it then cuts out and won't start untill it has cooled for a very short period of time. If the temp is set so it wont exceed 50 degrees, it is fine (not very warm water tho hey?).

[Central Heating] Works fine!? Allways reaches full temp if control set to full. Never 'cuts-out'.

Any suggestions as to the problem with my boiler?

Many Thanks.

 

[Agile]

Presumably your comi boiler is a Linea 24?

My first guess would be a partially blocked plate heat exchanger.

But I would want to ask a lot more questions like what does the temperature show when you run 9 li/min of hot water with the DHW temp set at maximum!

Tony

 

[allallyouyou]

Correct it is the Linea 24, is anymore I could do to help provide more information about the problem?

The boiler is only 5 years old and has been hardly used until this year (house been stood empty majority of the time).

Thankyou for your response.

 

[weareleeds]

While you are @ boiler with hot tap running put your hand on the filling lever (used to put water in boiler) as soon as burner goes out turn from 12:00 position to 09:00 position while observing temp display. The display stops reading dhw temp & reads blr temp if it shows around 80 degrees the plate heat ex is blocked

 

[dmitch071]

I belive this model has a non return valve in the outlet of the secondary heat exhchanger, this or the actual heat exchanger could be blocked.

 

[allallyouyou]

Will try that but at the moment its refusing to turn on