Heating and water system

[Neilmagee]

Hi I am trying to get my system as efficient as possible but am a bit baffled by how my system operates. I have a regular boiler, nest control and an unvented water cylinder. So a few days ago I noticed my boiler had an F1 message and the pressure had dropped so basically I guess it wasn’t on. Not a problem as I have often had to reset it. However it got me to thinking why have I still been getting hot water as when I read up on it I read my boiler heats the water in the unvented cylinder but this can’t be the case as my boiler isn’t on. Also I switched off the heat water via my nest but still after three days the water is still boiling hot. This leads me to believe that seeing as the unvented boiler is wired directly to the mains it is just continually heating the water 24/7 and is not the most efficient. Our bills are high for just being my wife and I and we don’t use much hot water. Any advice appreciated

 

[ShaunCorbs]

Check the immersion isn’t on but likely as you don’t use much hw your tank is still 1/3 full of usable how water

 

[Neilmagee]

Check the immersion isn’t on but likely as you don’t use much hw your tank is still 1/3 full of usable how water

What is the immersio. Is that not an older thing

 

[ShaunCorbs]

An electric back up heater should be on a switch

 

[Neilmagee]

What is the immersio. Is that not an older thing

Thanks for advice. Can I ask this. My unvented cylinder is hard wired into the mains and I leave it switched on. Is that correct or if it’s switched off would the sysyem boiler then just heat the water

 

[ShaunCorbs]

Mains water I’m guessing you mean ? If yes that’s fine and that’s how it’s supposed to be