hot water tank fizzing

[matz]

Hi, could anyone shed some light on something that doesnt seem to be quite right with our hot water before I call someone out?

Got a hot water cylinder and when its on immersion only, the tank gives fizzing sound.

Also, when immersion is off and boiler works the hot water (on hot water setting only, no CH) the boiler keeps kicking in and out (a few times a minute) and again gives a kind of fizzing sound.

All the above happens when there has been no demand on hot water for a few hours or more.

If I didnt know different, I'd say theres a stat on the cylinder faulty and the water is "boiling" and the boiler cutting in and out is the boiler shutting down becuase water is too hot? am I on the right track?!

 

[Dan Robinson]

It is the water boiling when in contact with the element. You probably have hard water in your area.

 

[matz]

yes we do have hard water! would this be the cause of the boiler cutting in and out in quick succesion?

 

[Agile]

Not directly, but scale deposition on the heating coil could!