Central heating coming on when heating the water?

Hello,

We had an issue with the boiler a while back, it broke down and wasn't heating the water, bloke came and fixed it but now everytime we have the water on the heating (ie radiators) come on full whack - the thermostat is turned right down, and we have a panel below the boiler that you can use to turn the water on and off, and it also has a button for the radiators, this is turned off, yet, they ALL come on.

I've tried turning all the knobs on the radiators that have them to jus turn them down, but they come on regardless. With the weather lately, and the fact we have a full 8-9 hours of blazing sun coming into our flat, it's like torture being in here cos it just won't cool down properly.

It's a Maxol Microturbo 40H boiler, the panel underneath is a Danfoss CP15, and the hot water storage tank is a Systemate SP 144.

Any help or advice greatly appreciated, it feels like you're being cooked alive at times.