New to Central heating - why does heating when its supposed to be off in summer?

[Silversurfer33]

Hi

RE: Why does the heating go on when its supposed to be off in the summer

I'm new to understanding how central heating units (boiler) work. Its summer and i've switched all the the central heating switches off on my Suanier Duval boiler except for the hot water ...which makes the water hot in the shower and kitchen.
Why does the central heating go on from time to time when some one is in the shower?

Can someone please help me undersdtand this and possibly remedy the situation?

Many thanks

 

[stevetheplumber]

Depends which system you have need more details

 

[GrahamM]

What is the exact model of boiler?
Initially sounds like a divertor valve issue.

 

[Silversurfer33]

right, apologies - i have a Saunier Duval Combi boiler F 23 E - its a sealed system,

 

[Silversurfer33]

thank you.

 

[diamondgas]

Hi silversurfer33,

It's most likely the reversing valve is passing ... Not the nicest of parts to replace as saunia's tend to leak for fun!!