PigletJohn - can I ask your advice on my hot water timer please?

[MixedHerbs]

G'afternoon PigletJohn.
I have a hot water immersion running on Economy 7. Therefore I expect NOT to hear any noise from it after 7am. But I am hearing it hiss as if it's heating water up to 8am. The visible clock is reading the right time (in BST) but is there an internal clock I could look st if I remove the front panel, after cutting off the electricity supply. Here's a photo of the controller.

is either of the neons glowing?

Have you got a timeswitch in, or beside, your electricity meter?

It's possible that the setting was put to "up to 8am summer time (up to 7am winter time)" This is not a user setting, it has to be done with the power off and involves opening up the casing. I don't know if I've got the installer instructions, I remember them dimly.

Do you know the off-peak hours on your electricity tariff? If necessary you can change the displayed time and trick the timer into thinking it is some other time.

Depending on the size of your cylinder, it would normally be fully hot within a couple of hours, and the thermostat should then turn it off. Is your tapwater unexpectedly hot? What colour is the cylinder?

p.s.

At 8am summer time, it thinks it's 7am. It doesn't actually change summer and winter, and you shouldn't change it. It works on GMT all the time.

Thank you Piglet.
I wouldn't expect either neon to be on at this time? I've realised that in the morning when I hear the 8am hissing/heating noise, I haven't checked to see if the Timer neon is still on ie that it is actually working at that time.
I'll do that in the morning.
I just want to be sure that it's not heating water after 7am, ie on normal electricity rates rather than a Economy 7.
I'll find the little key thingy and have a look in the meter box outside. No timer in the fuse box though. The only timer seems to be the one fitted.
You're helping me reason this out anyway - if I change the clock forward a couple of hours, then it will finish any heating of water earlier so no chance of it going over the Economy 7. Is that right...[confused look]

the offpeak times on your tariff may also be set in GMT.

Only your supplier knows your offpeak times, though you may be able to see or hear your meter changeover if you are looking at it at the time.