hot water going cold

[Russell0121]

Hi
We are having problems with our hot water maintaining its heat.
Whilst in the shower or when running the bath it is initially hot after a while it actually starts to go cold.
Normally have to turn it off leave for a while before it gets hot again.
We have a flowmax thermal storage unit/cyclinder system. Which uses mains pressure and has 2 pumps. Fitted circa 20 years ago. Says it is an IMI range.
Radiators work fine.

I have tried turning the mains pressure down this makes no difference.
A plumber took the blender off and said it looked ok so put it back.

I am wondering if the expansion vessel has the correct pressure iof that affexts it? dont know.
or
If the heating plate / coil assuming there is one is an issue maybe scaled up?

Can anyone help please.
The kids are always complaining that the bath is cold or not very deep.

Best Regards

Russell0121

 

[stevetheplumber]

could well be scaled up they can be descaled with a machine

 

[Russell0121]

Hi Steve,
Thanks is that the heating plate inside the cylinder?

Russell0121

 

[CM25]

I'm not familiar with ur particular thermal store but generally if uve got a blending valve on the hw u don't normally have a plate to plate. Sounds very much like a faulty blending valve.

 

[Russell0121]

thank you