How to reduce temperature on santon premier plus hot water cylinder

[Matt M]

Hello. The water from my hot water taps is close to 70 C. I want to reduce this to nearer 60 C. I opened the panel on the hot water cylinder, but there are two dials. There’s one towards the top right that can be adjusted with a flat head screwdriver, and another blue dial towards the bottom left. Can somebody please tell me what each dial does? Which one controls the temperature?
Thanks
Matt

 

[Agile]

You need to tell us how you are heating your hot water. Boiler, electricity or both?

Furthermore anyone working on unvented cylinders should have the appropriate certificate.

 

[Matt M]

Hello Agile
There’s a couple of pictures with the cylinder details and control panel. It’s heated indirectly from a boiler downstairs.
I just wanted to lower the water temperature from taps slightly (but over 60C for legionella).
I haven’t got the appropriate certificate so perhaps I should leave it.
Thanks anyway
Matt

 

[Agile]

Well you could measure your tap temperature digitally for reference.

The adjustment at top right is for the stat to bring on the boiler. You might turn that a little anticlockwise.

The qualification is primarily to see if the cylinder is correctly fitted with the appropriate safety devices.

Does the motorised valve close under spring pressure when the boiler turns off?

 

[Madrab]

You should have the manual for the cylinder? It will all be in there. Has it always been too hot or is this more a recent thing? The max setting on the cyl stat is 72deg so I'd be surprised if the HW was 70deg at the tap. What is the temp setting on the boiler?

Might be an idea to get someone in that's qualified for unvented and gas (if you have a gas boiler) and get them to set it all up for you as you want it.

 

[Matt M]

I’ve adjusted the tap temperature now by turning the dial anticlockwise. The temperature was 68 and is now 62. Thanks for your help.
The motorised valve does close when boiler is turned off. The boiler is oil. A firebird environmax.
Still not sure what the blue dial pictured below is for. Might it determine how long hot water continues to be fed to the water cylinder after it has kicked in from the stat?

 

[Agile]

The blue knob is only to control the temperature the water reaches when you are heating it with electricity.