Very hot water

First of all let me say what a great forum it has been very helpful in understanding how these units work.

I have an issue in that my hot water is very hot to the point it could scald. Is this to do with the mixer valve not being set correctly as my hot water store also seems very hot and it has dried out one of the plastic covers on the top within 7 months. I know it could have been a faulty cover but the store does seem to be very hot or do they not have a temperature control is it set to one temp and the water controlled by the mixer ?

thanks
James

Hi James,

Your Systemate III should not deliver scalding temperature water to the hot taps. This indicates the blender valve is either not working or not correctly adjusted. It has a white or green plastic control knob on top, about 40mm in diameter, just to the right of the header tank. Look carefully on the top of it to see the arrows telling you which way to turn it to adjust the maximum hot water temp.

If adjusting it makes no difference then it is broken (or seized) and needs replacing.

The header tank should not get hot. Warm perhaps but not HOT! This suggests it is over-filled and the open vent is under water. This allows thermosyphoning to heat the header tank up to the same temp as the main store water.

Cheers, Mike

Mike

Thanks for the reply. Maybe I should have said the main tank also feels very hot to touch. When i press SW2 i get first readout as 60C the next readout is 38 and the final one is 70 does this sound correct.

The system has only just started feeling hot to touch. Before then it was warm but not hot.

Also the system keeps trying to turn the bolier on to heat say every 30 secs to a minute for quite period of time. It will then stop. This has been when the watre in the top tank has been about half way as well as topped up.

Hi James,

Yes those temp readings sound absolutely fine and normal.

The system SHOULD shut down completely once hot though. Continued operation of the boiler suggests the diverter valve is sticking on yours (a common problem). A new valve body is needed if this is the case. Fiddling around lubricating it or changing the actuator will not fix it other than temporarily.

Which bit of the 'system' feels hot to the touch?

The pipe work and the actual tank feel hot and as stated before the header tank is hot. That makes sense about the valve. I assume its a drain down then replace for the valve ? Woudl the vavle staying open cause the pump to keep on as well ?