rdc box trips on off peak

please could you advise? each night when the pulsacoil comes on at 2.30,it stays on for 5 minutes then trips all my electrical sockets.the red fault light doesnt come on but the green light goes off,if i switch the trip switch back on,the boiler comes back on but only to do the same over and over again,when using the boost switch there is no problem.I have had a bolier repair man from gled hill who says there is no problem,and i have also had a man from eon testing the electrics and replacing the meter,please could you advise where to go from here as morning cold showers are not good in december!!! thank you

Hi Boiler;

If you want to check this out during the day, you can swop the peak and off peak cables round with in the unit.
Has the off peak heater been tested with a meggar or insulation tester.I would have thought the Gledhill guy would have done that.Is the top heater leaking onto the bottom one?
Have all the connections for the bottom heater been checked including cables, flexes and switches.
I would have gone straight for the bottom heater but as it takes 5 minutes to trip I hesitate. When it is on for 5 mins can you hear the heater heating up?

Hi Mike,

Yes, when the unit is on for the 5 mins before it trips, i can hear the heater heating up.

Thanks for the initial tips, really appreciate the advice!

Is it worth calling Gledhill out again (the unit is still under warranty) and pointing out what you have suggested?

Kind Regards

Yes Call Gledhill
As the faults seems to be the unit.
Explain that you can hear it heating then after 5 mins it trips.