Electromate 2000 Tariff Question

I've just rented an apartment which is fitted with what I believe to be the 9KW version of the Electramate.

My Question is on the tariff, currently it's on EDF 20:20 which seems odd as the off peak rate is only 20% less than peak, I've contacted EDF who can change the meter to a Standard E7 tariff or E10 but the question is which do you think this is correct ?

Flat is only 4 rooms, two below ground, mainly single occupancy and I'm out at work most of the day. I do however need to keep costs under control so I'm trying to find the best possible option.

I know E10 is recommended for this type of system but the Legrand time clock installed in the fuseboard only has one on/off program, per day which is set for 0:00 - 07:00 which tends to suggest that E7 was used at some point in the past.

However on 20:20 (12.25 peak / 10.29 off peak) there is little advantage to having the time clock at all, however the on peak unit cost is lower.

The way I see it my options are :

1. keep the 20:20 and pay a lot of off peak but if the store charges during the day there is not a massive difference.

2. Switch to E7 with current time-clock

3. Switch to E10 that the system is intended for an replace the time-clock ?

Need to make an informed decision as whatever I do I'm stuck with it for a year, I also know that the apartment next door is also on 20:20 and they owe EDF £££££££££.

HELP !!!!!!!!!!

Both the 9kw and the 12 kw shuld be on eko10 for the best and most eko operation, that is regarding to the design. If u not using the stored energy , you will not loose any, course the unit is good isolated an sore the energy for up to 10 days with no use. Also your boiler is fully them. contr. and will not use any electicity if you not use any HW or heating ( exept for the control pcb ( ca 5 watt/h)
I hope this helps
regards Mario

I noticed u are confused about the time clock, depending on the installation on your boiler, the timing should be dun direct from your electric meter, ( is your meter switching to lohw cost energy, ,a signal is received from the EM 2000 to start storing more energy to make the energy stored for the time the normal rate is on.
On EM2000 9 kw this would be a normal 3 amp cable going to a small pcb. this is linked with a flat cable to the main pcb centre.

Thanks for your responses, This morning I had no hot water or heating so I took the cover off to have a look at the status display and I think I've found out why its on the 20:20 tariff (even though I can't figure out why I've no heating, store is at 65 degrees but radiators are cold and no DHW Pressure gauge is at 0 and when it tried to add water it pours out of the automatic air vent ?)

Back to the thread :
The "Off Peak" input (From the clock in the fuse board) to the small PCB below the control board is not connected, the cable is there but its just terminated in a choc block and tied out of the way. To get the boiler running there is a link from L to the DHW connector on the interface.

Assuming my understanding of the manual this means that the store can charge whenever it likes, which may explain why it's on the ECO 20:20 tariff and the stupid bills.

I've also had another look at the time switch and it will support multiple on / off switching so assuming that there isn't a serious defect with the heatstore that prevents it working correctly on off peak power it looks like I should be able to go for E10 - Damn need to phone EDF again....

I've borrowed some kit from work to look at another AC problem (TV appears to be disliking the neon sign of the restaurant across the road) So I'll investigate the operation of the "off peak" control this evening.

Anyway all this is giving me plenty of things to do of an evening

As the no heat / hot water issue was a bit more pressing than the cost of running the EM2000 I had a bit of an investigation last night.

I found that the no CH & DHW where both caused by the system loosing pressure, I tried to top up the system but water poured out of the vacuum valve at the top of the boiler, which looking at the scale build up it has been leaking for some time. I Removed the valve, poked as much of the scale out as possible and then gave it 10 minutes in an ultrasonic cleaner, the amount of crud that came out was quite amazing, another wash out and a bit more shaking had the plunger was moving and when blowing through the valve most the air was being restricted I refitted it, It leaked but not as bad as before and I could get 0.5 bar pressure in the system which seems to be enough to get everything working again.

I've also reconnected the time clock to the off peak board and the off peak control also seems to be working correctly, as I'm been switched to E10 at the end of the month. I also disconnected the permanent link on the PCB from L to DHW - which If I understand the manual correctly will prevent the unit charging on peak ?

I had the plumber from the letting agent call in to look at a couple of other problems and he told me that as far as he knew the boiler had been running on the 20:20 tariff and switching when it felt like it for as long as he could recall, he also agreed that it was a mad way to run the system.