How can I get my Economy 7 times changed so my underfloor heating comes on earlier?

@Dusty60 an economy 7 tariff gives lower off peak (over night) electricity but the peak (day rate) is higher than standard. As the supplier sets these rates, that’s why no one else can adjust the timer. 
You could change to a standard rate but that wouldn’t give any off peak price as all times are priced at standard rate. 
The rates vary by region so you would need to check for yourself. 
https://plans.ovoenergy.com/

So basically if i change my tariff my underfloor heating will work 24 hours a day if need rather than just on the night rate ??

Yes

Thank you so much

I am looking into this as we speak

Cheers

Economy 7 (E7) is a plan devised to use electricity at a cheaper rate during seven hours at night when demand is lowest. When combined with night storage heaters, it can be an effective way of heating a house; these are basically just ordinary heating elements running through a load of special bricks. The bricks absorb heat while the elements are on, then release it slowly during the day. It’s likely that there were once storage heaters in your flat, which were later replaced by underfloor heating.

It’s the Distribution Network Operator (DNO) that lays down the times when they’re prepared to sell electricity at a discount, so not even your supplier can change this.

As you’ve discovered, E7 isn’t the right sort of tariff for houses with underfloor heating, or indeed any other sort of electric heating unless there are also batteries that could store the cheaper electricity for use during the day. You’ll have a nice warm house during the night, but it will be cold during the day. Batteries are still very expensive, though. If your underfloor heating is wired such that it only turns on during E7 hours, you’re better off without E7. On a standard tariff, you would pay the same price per unit all day; it will be more than you’re currently paying during the night, but less during the day. You should be able to see the difference on the Plans page. 

It should be possible to have this changed remotely by the support staff.