Hot water heater

[rob5]

Hi All,
hope you can help with this. I have a water heater that is for the domestic water supply only, no central heating just the hot taps.

The tank in the picture has two immersion heaters fitted , one in the bottom third and one in the top third of the tank. The programmer controls the bottom one and the top is just a boost. My problem is that the water gets so hot that it could cause a serious burn particularly to children. Despite reducing the time on, it does not reduce the temp just the volume of water available. I know that on an ordinary immersion there is a temp control in the head but this does not have one as only the wire is visible.
I guess I need to get someone in (electrician or Plumber??) but if they are unable to adjust then seems little point.

Or am I missing something obvious on the controls at the side which I thought were for maintenance only?
Any help very gratefully received.
Thanks. Rob
View media item 40881 View media item 40882

 

[Diyisfun]

Is there a manufacture/model no.?
Unless it is to supply boiling water (for tea/coffee, etc) there must be an inbuilt thermostat

 

[45yearsagasman]

OSO unvented cylinders should be fitted with a control thermostat, possibly behind a controls cover. You could isolate the electrics and have a look, but as its unvented I would recommend getting it checked by a pro and use the water with caution until it can be checked. It needs someone with a qualification for unvented.

 

[rob5]

Diyisfun,
the tank is the main storage tank for all of the hot water and I also would have thought that there would be a thermostat but if so then its well hidden! The tank was brand new, just over a year ago in a new flat, commissioning paperwork says all OK and its been that hot since then.
45 gasman,
thanks for the reply, the cables come direct from the switched surface boxes marked as top and bottom immersion, not looked to see whats inside but expect just the connection from the programmer and the mains. could there be a adjustment there??
Rob

 

[Dan Robinson]

The thermostat is behind each of the plastic covers.

A small white arrow about 3 or 4mm long below the big black block with the wires attached.

Turn the power off before you go poking around. You will see the numbers. Use a flat bladed screwdriver to adjust.

 

[rob5]

Dan-R,
thanks for this but which plastic covers? do you mean inside the immersion switch or inside the plastic hexagon nut on the tank ( you can just see one of them in the picture).
thanks for taking the time to help.
Rob

 

[rob5]

Dan-R,
not sure why this did not come back up to the current posts but you kindly answered my question but still not sure where the thermostat is. Are you saying its behind the switch marked immersion or behind where the wire goes into the tank.
thanks again.
Rob

 

[dcawkwell]

under one or both the plastic covers there wil be a thermostat that looks
like nothing more than a screw head and a small scale next to it.
check the manual for the cylinder you have . should be available on the oso website.

 

[Dan Robinson]

Or take a picture of the inside and we can am end it.