Shower is always cold in the morning, but taps are warm

[tommtomm]

Hi there all,
My wife is giving me huge grief about the shower please help.
Ever since installing a new water tank as the old one was leaking, the hot water in the shower has become crazy.
Hot water in all the taps, but as soon as I turn the shower on in the morning, the best it gives out is slightly warm. I run it for 5, 8 minutes and still nothing, I turn it off and leave it for 15-20 minutes before turning it back on and I have nice hot water.

Please help me I am guessing there might be some blockage but it doesn't make sense, why it gives hot water after 20 minutes and not before.
This has been happening 90% of days.

Eternally grateful for any help.

Tom

 

[mrlennie]

Never came across that before. Either block or mixers dodgy?

 

[justlead1]

Hi. It dont add up? If it works fine and then not, it unlikely to be a static blockage (an odd sock floating about in the CWS Cistern can have this effect) It may be on the end of an exceptionally long run of pipe?
It could be starved by the use of other hot taps whilst using shower.
I am assuming its a hot water cylinder isfeed from a CWSC. And heated via a boiler or immersion heater?

 

[Scottley]

What kind of shower valve is it? If its thermostatic my money is on something stuck in the cartridge. Id take that cartridge out and check it, flush the pipework and try it again.