Boiler off but still heating water

[phil39]

Help please,

I have an ideal classic NF 50 boiler, and it is turned off on the timer, but it is still heating the hot water, without me needing to turn it on or to boost the system.

Why would this be?

Do I need to get a new boiler, or is it easily fixed?

 

[kevplumb]

zone/ 3 port valve

 

[Alfredo]

Its still getting a signal from somewhere if the buner stays on. Does your system have two two port valves or a three port near the cylinder. It could be that this is stuck in a demand position and completing a circuit. Either that or the programmer is jiggered..you might try a reset if it has a reset button, or it has a frost stat that is jiggered or been fiddled with and brings the boiler on when it shoudln't.

Either way something is completing a circuit which shoudl not be. A boiler fault is the least likely if my interpretation is correct.

Alfredo