Shower hot then cold but taps and ch ok

[blobbi]

I have trailed through the forums but found nothing that is exactly like my problem.

We have a volkera option boiler which we have just had serviced and parts replaced. This is because it was packing up for both hw and ch. it is much better now, and we plan to replace it in summer, but we still have a problem. The shower temperature fluctuates and the boiler goes on and off whilst it is on. We have a two year old thermostatic shower. Thing is, the bath water does not fluctuate despite it being on the same thermostatic valve. All the other taps and the ch work well. Any ideas?

 

[Whitespirit66]

Maybe shower head is too restrictive. Try removing it and see if it improves. Another problem maybe if the head is partially blocked with limescale. This could cause the boiler to cycle.