Economy 7 immersion heater coming on during the day

Gerry1

The ideal scenario is that the meter switches a dedicated circuit supplying the bottom immersion heater so that you get a full tank of hot water overnight at cheap E7 rates.  Provided that everything is correctly configured (including the night rate readings being charged on the bill at night rate, not swapped over) then there shouldn't any problems with wrong times: the Radio 4 Long Wave signal on 198kHz makes sure the switching takes place at the correct times (although it can vary +/- 15 minutes).

You also have a Boost heater in the middle connected to a 24h circuit to give an expensive half a tank if you run out in the daytime.  This should normally be left off.  Ideally it should have an 'egg timer' switch or plunger so that you can only get an hour or so and can't accidentally leave it on.

Unfortunately, a cheapskate solution is to use just one 24h circuit to supply both heaters, and to mimic the E7 times with a timer in the Boost heater supply.  That's often problematic because it may have been set incorrectly (some areas have a 2hr peak rate slot from 0030 - 0230) and cheap motorised switches are thrown out of sync by a power cut.

Unusually, it sounds like the OP's problem is with the radio teleswitch, but the Boost circuit needs to be investigated as well.  Note that it seems wrong to have a time-of-day timer connected to the Boost heater; this would normally control the lower E7 heater.  These wiring and timing problems may be in addition to a drifting radio teleswitch.

adamwebb28

Thanks. So if I'm understanding things right, the immersion heater is on because the teleswitch has changed to night rate which appears to be happening far earlier that expected. Which I guess explains why my day/night usage revered on my first meter read after moving to Bulb. 
I have checked and the light on the Economy 7 switch goes out when the meter is on the day rate so it would appear it is linked to meter correctly?
So what could cause the teleswitch to be out of sync? Does it not just change when the signal changes?

Gerry1

The teleswitch will drift like a forgotten digital wristwatch if it loses the R4 signal. You could use a portable radio to check whether R4 is badly screened or suffers local interference but it's a very long way out so it's more likely to be faulty.

Note the exact times when it switches on and off (possibly two on and two off) and then report it.

The good news is that the light on the Economy 7 switch goes out when the meter is on the day rate, so once the teleswitch is working correctly you shouldn't have to worry.  But what is the timer on the Boost heater doing?  You certainly don't want that kicking in automatically on the day rate and wasting money.  A photo or link would help.

adamwebb28

Just as an update, it looks like its on night rate from 3pm to 10 pm. It seems strange that it happened at the same time as switching suppliers though?

Gerry1

adamwebb28 said:

Just as an update, it looks like its on night rate from 3pm to 10 pm.

Ideal if you don't have gas and rely on plug in heaters !  But you might get a nasty shock if they notice it's wrong and try to back bill you based on your usage afterwards.

Have you checked that the register that clocks up between 3pm - 10pm is actually billed at the cheaper night rate?

adamwebb28

Yes it does, I can see the lower rate number ticking up at the moment.