iHD Red Everytime I Switch Anything On

Comments on the last few replies:

1. The water heater looks to be a model DHF, which is available with ratings from 13 kW to 24 kW. It has no tank; the water is heated on demand as it passes through, just like an electric shower unit.
   
   I agree with the suggestion to try running it at the medium setting, which should deliver hand-hot water at more-or-less mains pressure. The highest setting comes with a risk of scalding, but it would take an electrician to determine why it’s tripping its 40A breaker after running for some time.
    
2. The underfloor heating is almost certainly the cause of the high bills. If it’s thermostatically controlled, it’s natural that it should fire up at the coldest part of the night, when it’s probably not doing much good as the occupants will be tucked up in bed for some hours yet. I don’t know how long it takes for its effect to be felt, so some experimentation would be in order to establish the warm-up time. 
     
   Fitting it with a timer would certainly be a good way of saving energy by setting it to start at (getting-up time less warm-up time) and stop some time later to avoid the silliness of continuing to keep the place warm after everyone’s gone to work. Similarly, I’d time it to start at (getting-home time less warm-up time).
    
   I might even think of turning it off once I get home, then boost the temperature just where I happen to be using a little fan heater or similar. For snuggling up in front of the TV, I’d wrap myself in an electric throw costing 1-2 p per hour to run.

  
Underfloor electric heating was a good option when electricity was cheap. Those days are sadly behind us.

​@Firedog , looking at the heating control here 

the heating is only consuming some 30% (approx) of the daily electricity (if my calculations are correct) meaning that there must be some other significant energy being drawn. 
The hot water device I saw (after a google image search) suggested what I have mentioned earlier. 

Thanks everyone for the suggestions. I’ll try turning the water down and see if that works. 
At the moment the underfloor heating has a thermostat control but you can change the program to come on/off at certain times of the day so it comes on at 6am for an hour and 6pm for an hour that’s it. I’m not sure how accurate the energy readings are on the underfloor heating control but that has me using about 7kw/h of energy a day my bill has me using approximately 27kw/h energy a day total so huge difference. 
The things switched on permanently are fridge/freezer, oven and tv (standby). Oven used maybe 30mins a day average, tv 5hrs a week average, 1 load of washing a week. I only have a light on if I’m in and it’s only ever the room I’m in. 
 

Thanks everyone I have solved the issue with your help just not the solution. I’m at home now when electricity seems to be peaking with nothing on and see my usage high orange on IHD. Looked at my underfloor heating thermostat that’s showing target of 16c which is what I set it for except for twice a day but that the actual temperature is 21c. Switch it off at the plug and IHD  goes right back down to bottom of the green.

what I don’t understand is why have a timer on it if the thermostat over rides it and switches it on

Then the peak usages at 04:00 and 13:30 must be from something else, unless there’s a ‘frost protection’ safety setting that prevents a complete shut-off. I’ve heard of UFH that was turned off before the householder went on holiday, but managed to consume lots of electricity nonetheless because of this sort of feature. In that case, the temperature wasn’t allowed to fall below 10°C. I can understand this being sensible (at a lower threshold) for a wet system, but electric? In a flat?

Can you trace anything like this in the UFH settings, ​@bonniejean? 

I can’t see how or why an on-demand water heater could suddenly start drawing more than 2 kW in the middle of the night. It’s quite possible that UFH would, though.

PS I just had another look at ‘yesterday’s’ half-hour data. This was, I think, after the UFH was set to come on at 06:00 and 18:00. There is no spike in the morning, which would suggest that the thermostat was satisfied at the time - presumably because the place was warm enough after its mysterious activity a couple of hours earlier.

Perhaps we need to see Friday’s figures, when we know that the UFH was allegedly off between 19:00 the previous evening and 06:00.  
  

Yesterdays attached I was out between 7.30am-7pm