Hot water leaking at overflow

[jsm]

Hi
Overflow suddenly spouting out luke warm water to outside of house, checked on down pipe in photo leads exterior overflow, could put finger spout when overflowing and its luke warm water.

Why is it overflowing? Lot of water coming out.

Photo attached of side of tank to show above.

What is wrong???

 

[Deleted member 120897]

Could be temperature/pressure relief valve. Have you had the unvented cylinder serviced?

 

[jsm]

Could be temperature/pressure relief valve. Have you had the unvented cylinder serviced?

Yes,
Is the IMI Tribune11 (unvented mains pressure cylinder) a bubble top one, as I don't have a white expansion vessel, can't find manual on it anywhere to confim

 

[smartplumbinghawaii]

High water pressure can also cause the pressure relief valve to release water. You can use a pressure gauge to measure the water pressure in your home. If it exceeds the recommended range, you may need to install a pressure reducing valve.

 

[king of pipes]

Over time the cylinder can loose its air bubble there is a floating baffle inside your cylinder the air gap needs resetting, turn off the mains cold water supply to the cylinder open up 2 hot water taps and leave them open go back to the cylinder,
The black knob on the pressure relief is spring loaded turn it clockwise until you feel a click hold it in that position hot water should drain from your taps and copper pipework realeasing any built up pressure , once the water stops it's simply a case of shutting the relief valve close one hot tap, then slowly turn the cold supply back on refilling the cylinder this will reset the air gap water will vent from the hot tap let it run for a minute or so then switch off , Try this and see if it cures your problem. Kop