Vaillant Sine 18 hot water problems

[simonsays2013]

Hi - the hot water on my Vaillant Sine 18 only comes on now when the central heating is on (apart from very rare occasions). I don't know if this is relevant, but the hot water flow also seems reduced. An engineer looked at it - though he didn't go inside - and says I may need a new diaphragm, but he seemed dismissive of the reduced flow. He also talked about the wax capsule. Does he sound right? Does anyone have any ideas please?

Thanks in advance for any help

 

[Agile]

It does sound as if the water section underneath is not working.

But normally it would then still give hot water if you select the hot water preheat!

Tony

 

[simonsays2013]

Thanks - but any idea what could be wrong and what I need to do? Is it the diaphragm as suggested or something else? As I say, the hot water always works when the central heating is on.

Simon

 

[Agile]

It sounds as if the water section is not working. I have not seen it so I don't know why in your case!

But I would still expect it to give DHW when you have selected DHW preheat. But you have not commented on that!

Tony

 

[ianmcd]

Tony where is the HW pre heat on a SINE 18 ?

 

[ianmcd]

OP re-post your question and put" Bunny help please" in your post heading , there are some great minds of information on here who can help you ,

 

[Agile]

Press the top of the right hand piano key.