Boiler stove query

Hi, looking for some advice on a recently installed boiler stove, a 25Kw Henley Sherwood multi fuel boiler stove spec’d for 16 radiators, heating 12. plumbed in open vented into our existing oil heating system. I’m convinced the electrical control side is wrong. The electricians have placed a stat on the water pipe exiting the stove, when this stat hits 60 deg the controller opens 3 zones, hot water, downstairs, and upstairs, when it goes below 60 deg it closes again, and keeps repeating this cycle. Even with a blazing fire and the stove lit all day, the rads are getting lukewarm at best and the older radiators in the house are barely heating at all. When the stats opens the motorised valves a circulating pump kicks in for about 1 minute max and then obviously the heat in the water drops and all 3 zones shut and the pump switches off, it’s repeats this cycle for the whole day.

Any advice greatly appreciated 🙏🏻