Ideal Isar HE30 Radiator Issue

[Mindboggling]

My Ideal Isar HE30 boiler is heating my radiators when hot water is requested. I have changed the diverter valve but the problem continues.

Any ideas?

 

[shambolic]

Did you change the head and the body or just one of them. If so it will be the other one that wasn't changed(probably the cartridge in the body)

 

[Mindboggling]

Thanks for your reply. I changed the cartridge.

Do you think I need to change the head as well?

 

[shambolic]

Take the head off and make sure it motors open and closed properly and the White plastic bit inside actually moves as I've seen a few cracked so they don't push in spindle on cartridge.