# fuse blows after installing timeswitch

No insulation is perfect so it will start cooling down and switch on again. If you are not in during the day it is better to time if off when you leave and on again shortly before you get back.
Even better to switch it off before the shower so there is less heat to escape in the mean time.

So if it loses the typical 20p worth of energy per day, how much do you think you will save by turning it on and off?

Pence.

What does the timer cost?

https://www.phamnews.co.uk/erp-tightens-the-rules-for-cylinder-manufacturers/

So if it loses the typical 20p worth of energy per day, how much do you think you will save by turning it on and off?

My experience with a 200L version:
1 hour/day, 0600-0700. ~1,5KWh
1 hour twice a day, 0600-0700 & 1200-1300. ~2-2.5KWh
2 hours/day, 0600-1800. ~2KWh
8 hours/day, 0600-1400. ~3KWh
24 hours/day. 4-5KWh

This was in a non insulated workshop (Farm building) Winter time allow another 10-20%
so difference between 1.5 and 4 KWh is 2.5x20p=50p/day or £180/year

What does the timer cost?

This one will be to modern, high standards of insulation.

its white, brand new.

Your 200 cylinder would take over 3 hours to heat, so obviously heating it for 1 hour a day will not be enough.

This one will be to modern, high standards of insulation.

Your 200 cylinder would take over 3 hours to heat, so obviously heating it for 1 hour a day will not be enough.
How much has it changed since june 2020?

according to the manufacturer standing heat loss would be 1.25 kwh/day at 65C, probably slightly higher due to loss on pipes but yeah, even assuming the cost of electricity will ramp up quite a bit in the next few years its likely not going to be a massive difference. the timer was around £30.

This one will be to modern, high standards of insulation.

Your 200 cylinder would take over 3 hours to heat, so obviously heating it for 1 hour a day will not be enough.
Are they less efficient than the old copper unlagged cylinders then?

Are they less efficient than the old copper unlagged cylinders then?
Apologies, thinking about size, I doubt it's as big as 600mm diameter and 1m high, allowing for insulation I'd guess it must be more like 100L.

How long do you think a 3kW heater takes, to heat 1 litre of cold water?

How long do you think a 3kW heater takes, to heat 1 litre of cold water?
It isn't cold, it's a well lagged cylinder and still warm from the previous day.

EDIT: But in the days we heated a 18x36" copper cylinder with an immersion heater it was plenty hot enough for a bath in 20-25 minutes. I don't know how long it would have taken to reach a full 65', that was only ever a mistake. I'll guess 90-120minutes

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I've just timed the kettle with 1L, from cold tap @8' to clicking off 42 seconds, so 90' rise of 100L ~75 mins to boiling, I'll guess from that 55' rise ~60mins

Ahhhh, ye cannae tamper with the laws o' physics, Captain.

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That timer is probably not designed to supply two elements, from what I can see - if you were to remove one of the two browns from the rightmost terminals and add a connector to make sure it is insulated, it would enable you to get one of the two elements working temporarily. If you can check and make sure it is the brown for the shorter element, even better, but...

so I've removed the wire on #1, the timer is on override always on. it shows to be powered and on from its LEDs without fuse issues,
but 3 hours later I can't tell much of a difference in terms of water temperature, I'm not sure if I'm missing something here. is the insulating connector necessary?
I'm trying plugging 1 back and removing 2, it might be too early to tell but doesn't seem to be doing much either..

say I wanted to temporarily reinstall the original untimed switch I posted earlier and have a shower, how would I go about wiring that correctly?

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