Shower runs hot and cold

[nickwri]

Hi,

My Aqualisa power shower is intermittently running hot and cold.

I have a conventional Potterton boiler (quite old), and don't have any other problems with the heating system or other taps.

One thing i have noticed is that my header tank in the loft has started to overflow. The ballcock is fine, but there is a pipe which comes from the cyclinder cupboard in the bedroom below, into the loft, up to the roof, and then curves back down into the header tank. Is this a vent pipe? Could this shed any light on the cause?

Thanks in advance for any advice.

 

[seco services]

what model aqualisa is it ?

as for the cws filling i would say you have a mains cold gravity hot appliance passing cold water back to the hot water so filling the cws.

is the shower connected correctly ?

 

[nickwri]

Thanks for the quick reply!

Not sure what model the shower is - its been in for nearly 10 years. Its a fixed head with knob turn control embedded in the wall. Heat setter is a dial integrated with the control knob.

Can i ask what cws is, and typical example of what a "cold gravity hot appliance" might be.

One other thing, the shower is pumped by a Stuart Turner 1.5 bar pump, again around 10 years old.

 

[seco services]

cws - cold water storage. tank in the loft.

a mixer tap ie the kitchen tap will be cold mains water gravity hot water.

 

[nickwri]

Could these 2 things being connected in anyway i.e. shower running hot/cold, and cws overflow, or are they seperate?

What would you suggest i do next?

 

[seco services]

the shower issue i would say is poss a cartridge issue.
a pic of that will help id it.

is the tank filling constantly ?
i don't think the showers related because they are both gravity feeds from the cws in loft.

but if you have any isolation valves on the cold/hot pump pipework
isolate them for the night and that will prove its not the shower.

if you can see the tank filling isolate your mains stopcock and it should stop.