CH water hot, but hot water Luke warm

[pyounger]

My Dad has a heating system which is the conventional sort with header tank in the loft. The boiler has pumped heating and gravity hot water.

over the past couple of months the heating is fine, maintaining warm temperatures but the hot water is really just Luke warm. It does improve if the heating is switched off (which it often is these days), but it is far from what it was.

whilst I’m not sure what I’d be looking for, I can’t see any signs of a thermostat controlling the hot water tank, I doubt there is one as the small radiator in the bathroom is, I was told, linked to the gravity feed to prevent the hot water over heating.

the system was serviced by a registered engineer last October.

Any advice?

 

[muggles]

Could be scale if you're in a hard water area?

 

[DP]

Get a heating engineer to check for blockage in the tees that connect to the cylinder coil

 

[CBW]

Photo of cylinder cupboard and motorised valve(s)?

 

[ianmcd]

I can’t see any signs of a thermostat controlling the hot water tank

you cant have a thermostat on a gravity hot water system, the temp of the water is controlled by the thermostat on the boiler , possibly scale or some air in the coil

 

[ianmcd]

Photo of cylinder cupboard and motorised valve(s)?

motorised valves on a gravity HW systen @Chris_W tut tut mate

 

[CBW]

motorised valves on a gravity HW systen @Chris_W tut tut mate

Might treat myself to an eye test now opticians are re-opening and restrictions are being lifted or I could just read it properly Thanks mate.

That said, how many times have we found out system is different than what was described by OP

 

[ianmcd]

Might treat myself to an eye test now opticians are re-opening and restrictions are being lifted or I could just read it properly Thanks mate.

That said, how many times have we found out system is different than what was described by OP

Totally agree mate so many call an open vented system a gravity system, including some engineers