I had exactly the same issue the other week. I got though quite a few programmers as thought it was an issue with a batch of programmers. Turns out its an issue with the new Grundfos UPS 2.
Apparently according to Drayton tech support its a know issue. When the pump starts for some reason it draws a abnormally high current which causes the relays in the timer to fuse. Once this happens it is the end of your brand mew timer.
You can check the timer has fused by removing it from the back plate and doing a continuity check on the back of the timer between L and 3 or 4. They should be open circuit when removed.
The Drayton guy said they know it affects Drayton (iflo) and Danfoss timers, but were unaware of issues with other manufacturers. Draytons resolution was fit a Grundfos Alpha or a different brand pump.
Grundfos will not openly admit there is a fault however have a new version of the pump coming in September to address this issue. Hope this helps.