hot water only when cold basin tap turned on

[carriesue]

Have rectified previous problem regarding Worcester combi.
Anyone have advice to why hot water in the shower will only work if the cold tap to the basin is turned on. Many thanks

 

[Alanka]

What type of shower is it? Does it run off the combi H and C? Or is it tank fed with (or without) a shower pump?

 

[carriesue]

I have a Worcester Combi boiler. I do not know the make of the shower but it is a mixer. Thanks.

 

[charlie frederi]

is the shower thermostatic it may need a service as they shut down if the cold or the hot blocks to stop personal injury

 

[carriesue]

Thank you will get the plumber back again as now have leak thru' ceiling and it's not coming from the shower plug hole. I know nothing about plumbing but think it may be from the shower connexion behind the mixer facia. Thanks again