Our insures for our block of flats has entered a clause that we must have electrics checked. Is this normal and what would happen if we didn't have the checks done
This is quite typical. If you had a claim which was unrelated to the electrics it's unlikely the insurer would refuse to pay up, but if dodgy electrics caused a fire then you'd be in trouble. Look for the phrase 'it is a condition precedent to liability...' in the condition. if these words appear then strictly speaking your insurer would be entitled to refuse any claim, whether related to the electrics or not.