Pipe stat not effective?

[Nicmac]

I have a ideal logic max boiler ( installed in Nov 2021) in the garage, water tank and pump in airing cupboard in the house. I have a frost stat in the garage set at 5c and a pipe stat on the return pipe to the boiler set at 10c. So can anyone explain why my radiators are still heating up on and off through the night. Whilst it's been very cold (-t4 or-5c temps) I thought the addition of the pipe stat would prevent this?

 

[ShaunCorbs]

Because the return temp will need to get above 10c so the boiler will have to sent heat around

 

[Bypassboy]

Is it a s plan system..ie 2 motorised valves..and do you have a bypass valve…that is pipe after the pump connecting to the return from the cylinder…
If the programmer is off and both zone valves closed because of that, the heat is supposed to travel up the flow ,thro the bypass and back to the boiler thro the return..until such time the return rises to 10 degrees