"John Rumm" <see.my.signature@nowhere.null> wrote in message
news:t3mcge$snv$1@dont-email.me...
> On 19/04/2022 03:44, jon wrote:
>
>> I want to limit each instance of shower time to 5 minutes max, this is
>> equivalent to 9 pence at the current off peak rate.
>
> What kind of shower?
>
> Instant electric, or mixer? Power shower or pumped?
>
> When you say "limit", limit in what way? e.g. cut off flow of water, stop
> prodiding hot water?
>
> How is the limit "reset" for the next shower?
>
> How much do you want to spend?
>
>
>
> --
> Cheers,
>
> John.
>

It is an intantaneous heater of the 8kW kind. I suppose fitting a resettable
timer after the isolator.

On 19/04/2022 14:41, Jon wrote:
>
> "John Rumm" <see.my.signature@nowhere.null> wrote in message
> news:t3mcge$snv$1@dont-email.me...
>> On 19/04/2022 03:44, jon wrote:
>>
>>> I want to limit each instance of shower time to 5 minutes max, this is
>>> equivalent to 9 pence at the current off peak rate.
>>
>> What kind of shower?
>>
>> Instant electric, or mixer? Power shower or pumped?
>>
>> When you say "limit", limit in what way? e.g. cut off flow of water,
>> stop prodiding hot water?
>>
>> How is the limit "reset" for the next shower?
>>
>> How much do you want to spend?
>>
>>
>>
>> --
>> Cheers,
>>
>> John.
>>
>
> It is an intantaneous heater of the 8kW kind. I suppose fitting a
> resettable timer after the isolator.

Just use a cistern with a flush, and make sure it doesn't refill too
quickly.

Oh, nearly forgot... ;-)

--
Cheers
Clive

Jon <jon@nospam.cn> wrote:
> It is an intantaneous heater of the 8kW kind. I suppose fitting a
> resettable timer after the isolator.

You can get boost timers, eg:
https://www.timeguard.com/products/time/immersion-and-general-purpose-timeswitches
and maybe one of those has a programmable time delay. You press the button
before going into the shower which gives you whatever the programmed time
is, and then cuts out. You'd have to locate the button somewhere
inconvenient ;-)

However a shower is a fairly substantial load, so the boost timer couldn't
drive it directly. You'd need a chunky contactor (ie relay) in the mains
feed for the shower that's driven off the output of the boost timer.

Otherwise some showers (eg the 'digital' kind) have remote controls that
might be externally controlled.

Theo

On 19/04/2022 15:05, Theo wrote:
> Jon <jon@nospam.cn> wrote:
>> It is an intantaneous heater of the 8kW kind. I suppose fitting a
>> resettable timer after the isolator.
>
> You can get boost timers, eg:
> https://www.timeguard.com/products/time/immersion-and-general-purpose-timeswitches
> and maybe one of those has a programmable time delay. You press the button
> before going into the shower which gives you whatever the programmed time
> is, and then cuts out. You'd have to locate the button somewhere
> inconvenient ;-)

Fit it in the shower area. They only get the shock when trying to
operate it when they are wet :)

On a serious note some electric showers continue to run on for a few
seconds after the manual off switch is pressed in order to pass cold
water over the elements once they have been switched ofF, but this may
not be an electrical controlled delay

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 19/04/2022 14:41, Jon wrote:
>
> "John Rumm" <see.my.signature@nowhere.null> wrote in message
> news:t3mcge$snv$1@dont-email.me...
>> On 19/04/2022 03:44, jon wrote:
>>
>>> I want to limit each instance of shower time to 5 minutes max, this is
>>> equivalent to 9 pence at the current off peak rate.
>>
>> What kind of shower?
>>
>> Instant electric, or mixer? Power shower or pumped?
>>
>> When you say "limit", limit in what way? e.g. cut off flow of water,
>> stop prodiding hot water?
>>
>> How is the limit "reset" for the next shower?
>>
>> How much do you want to spend?
>>
>>
>>
>> --
>> Cheers,
>>
>> John.
>>
>
> It is an intantaneous heater of the 8kW kind. I suppose fitting a
> resettable timer after the isolator.

If you are planning to switch the 8kW load, then you will probably need
to use a contactor to do the switching, and drive that from some form of
electronic switch. It would need to be a fairly serious one as well. So
by the time you add an enclosure for it, and a time switch etc it would
take quite a while to recoup the capital cost in electrical savings in a
normal domestic setting.

You may be better off auto switching a playback device that can play the
birdie song at high volume after the shower has been running for 5 mins! :-)

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

Theo wrote :
> Otherwise some showers (eg the 'digital' kind) have remote controls that
> might be externally controlled.

If it doesn't have that, it will have a solenoid valve to turn the flow
of water on and off. That solenoid could be more easily operated by a
low current timer. The low water pressure sensor with then switch the
element off. No need for a clunky solenoid then.

Harry Bloomfield Esq <a@harrym1byt.plus.com> wrote:
> Theo wrote :
>> Otherwise some showers (eg the 'digital' kind) have remote controls that
>> might be externally controlled.
>
> If it doesn't have that, it will have a solenoid valve to turn the flow
> of water on and off. That solenoid could be more easily operated by a
> low current timer. The low water pressure sensor with then switch the
> element off. No need for a clunky solenoid then.
>

That doesn’t address the issue that many electric showers cool the element
for a few seconds before shutting off the water to avoid boiling the water
in the heater.

Tim

--
Please don't feed the trolls

On 19/04/2022 16:14, John Rumm wrote:
> On 19/04/2022 14:41, Jon wrote:
>>
>> "John Rumm" <see.my.signature@nowhere.null> wrote in message
>> news:t3mcge$snv$1@dont-email.me...
>>> On 19/04/2022 03:44, jon wrote:
>>>
>>>> I want to limit each instance of shower time to 5 minutes max, this is
>>>> equivalent to 9 pence at the current off peak rate.
>>>
>>> What kind of shower?
>>>
>>> Instant electric, or mixer? Power shower or pumped?
>>>
>>> When you say "limit", limit in what way? e.g. cut off flow of water,
>>> stop prodiding hot water?
>>>
>>> How is the limit "reset" for the next shower?
>>>
>>> How much do you want to spend?
>>>
>>>
>>>
>>> --
>>> Cheers,
>>>
>>> John.
>>>
>>
>> It is an intantaneous heater of the 8kW kind. I suppose fitting a
>> resettable timer after the isolator.
>
> If you are planning to switch the 8kW load, then you will probably need
> to use a contactor to do the switching, and drive that from some form of
> electronic switch. It would need to be a fairly serious one as well. So
> by the time you add an enclosure for it, and a time switch etc it would
> take quite a while to recoup the capital cost in electrical savings in a
> normal domestic setting.
>
> You may be better off auto switching a playback device that can play the
> birdie song at high volume after the shower has been running for 5 mins!
> :-)

Trouble with that is others get subjected to the noise.
OP would be better off promoting cold showers:
https://www.healthline.com/health/cold-shower-vs-hot-shower#Whats-so-great-about-cold-showers?

Tim+ laid this down on his screen :
> That doesn’t address the issue that many electric showers cool the element
> for a few seconds before shutting off the water to avoid boiling the water
> in the heater.

That is why I said 'If it doesn't have that....'

Meaning if it doesn't have that cooling down feature, described in the
quoted paragraph I included. :oÞ