Disaster continues - underfloor heating help?

[JugglingChaotically]

So just when we think we have hit rock bottom and things can't get much worse, the kitchen won't heat up.
The heating installed by our ex builder was wundafloor.
It has tile on top.
And after 18 hours is only at 14c.
The system we have looks like this
www.wundafloorheating.co.uk/underfloor-heating-joists
but our floor is concrete with this on top, ditra mat to stop tiles cracking then tile.
Do I have to rip this all out?
Wundafloor website also says basic system designed
Can anyone tell me about underfloor heating....for energy efficient houses.
Ours is old drafty Victorian.
So how can I tell whether it's the base system or the one they sell for houses like ours?
Our build has been a disaster ......

Phew!!! Really hope it's ok :)

Well it was flow rate ......
But also the thick layer of plywood that was above the heating......
What to do?

So under the tiles? Will it not work properly with that in place?

The tiles will not feel warm to foot.
They will radiate inefficiently.
And take ages to warm up.
It's an insulator!
Oh and absorb lots of energy in the process.........
They will provide low level heat very inefficiently.
I can't face more delays or cost of ripping out and replacing them.
So we will add other heat s sources - something that I may regret every winter for years but right now I can't face any more backwards steps