Timer on hot water cylinder?

[p.dath]

What's involved with getting a timer put on your hot water cylinder to stop it heating during the day? I want to use cheaper night time power, 11pm to 7am.

I was thinking if they install it at the hot water cylinder it will keep getting turned off when they ripple the power off and on.

[Edbear]

That's the idea behind ripple, it turns your cylinder off during the day, or am I confused again..? Call your power company.

[jaffaonajappa]

What's involved with getting a timer put on your hot water cylinder to stop it heating during the day? I want to use cheaper night time power, 11pm to 7am.

I was thinking if they install it at the hot water cylinder it will keep getting turned off when they ripple the power off and on.

So, you can plug your hot water cylinder into 240v mains, like a normal plug/socket thing?
If so...theres them mechanical timers - have some on the lights for the fish tank. About $10 from mitre 10. Or $40 from specialist pet shops. (sound familiar....bikers? :P) Theyre a wee bit bigger thana double adaptor - similar concept.

[FJRider]

That's the idea behind ripple, it turns your cylinder off during the day, or am I confused again..? Call your power company.

THat is correct ... ripple control ... they do turn it on for a short period during the day to keep the water HOT ...

Turn it OFF all day would mean it would use a LOT of power to get it hot again ... more than normal ripple control.

But hey ... it's YOUR power bill p.dath

[pete376403]

So, you can plug your hot water cylinder into 240v mains, like a normal plug/socket thing?
If so...theres them mechanical timers - have some on the lights for the fish tank. About $10 from mitre 10. Or $40 from specialist pet shops. (sound familiar....bikers? :P) Theyre a wee bit bigger thana double adaptor - similar concept.

Your HWC element is going to be 2400w at least, maybe 3000w, so whatever timer you put in will require fairly healthy contacts (switching 10-15 amps) - not the sort of thing you'd find in a pet shop.
Also HWCs are permanently wired, so you can't use any sort of plug in device

[jaffaonajappa]

Your HWC element is going to be 2400w at least, maybe 3000w, so whatever timer you put in will require fairly healthy contacts (switching 10-15 amps) - not the sort of thing you'd find in a pet shop.

Ahhh. Good point.
And at ~3kw....i suspect its hard-wired?
Dunno - cant remember a time before instant gas

[neels]

Have a look in your meter board

If you've already got night/day rate then there should be one ripple control relay for that. If you've got controlled hot water then there will be one for that, and possibly another if you've got a night store heater.

Most hot water cylinders are hard wired and 2000 or 3000W, so you'd probably need to hard wire a timer and relay into your switchboard.

[St_Gabriel]

Speak to you power company to get switched from your existing un24 cn17/19 tariff to a un24 with a lower cost tariff running on either the ripple relay or a power company supplied timer. I dont know a whole heap of options but do know of what is called a ND16 tariff which usually gives a two register (two counters) meter with cheap power available for 8 hours and dearer power for the remaining 16 hrs (usually used on the likes of nightstore heaters). A sparky would be your only option in regards to a timer on the cylinder if it had to be mounted in the switchboard.

[Indiana_Jones]

If you wanna save a little bit off your power bill, could always lower your hot water temp if you have not already.

55-60C is all you need really

-Indy

[Grumph]

Been there done that - i've got a timer on my HWC and with standard economy all day rate it is a noticeable saving. With a night rate it would be more.
As far as increased usage to heat only once - not so as your cylinder should be well enough insulated to hold the water warm at least. It certainly does so for us.
Used in conjunction with a wetback our water heating costs are minimal. Timer only heats for around 4 hrs in the am which suits us fine - a family with kids would need more.
i used to work for an outfit installing nightstores - that's your main source of high amperage timers. We used to make our own from chinese plug in type which had a relay capable of handling 60amps - god knows why when the plug ins are limited to 10amps...I put 3 position switches on them on/off/manual override - useful if you wanted extra hot water at short notice.

[scissorhands]

Spend the money on insulation, its done in a flash. Do the ultimate job so you have no heat loss. Completly surround cylinder with wool insulation, batts if you dont mind the dust, either way wear a mask and cut the pieces and push behind, under over, all round, no gaps. Fill the whole cavity even 500mm thick is great.

Modify usage and turn down temp, I'm at 45 degrees C

Otherwise switching HW supply on and off can be done by a timer powered off the HW circuit, and not affected by ripple switching

A whole swag of polyethylene farm piping on your roof would heat a HW cyclinder on sunny days

[p.dath]

That's the idea behind ripple, it turns your cylinder off during the day, or am I confused again..? Call your power company.

The ripple relay allows the power company to turn off your cylinder at times of peak load.
I can buy much cheaper power at night, so I don't want to pay for more expensive power during the day.

THat is correct ... ripple control ... they do turn it on for a short period during the day to keep the water HOT ...

Turn it OFF all day would mean it would use a LOT of power to get it hot again ... more than normal ripple control.

But hey ... it's YOUR power bill p.dath

I don't believe it would use considerably more power over a 24 hour period. In fact I believe the opposite, it costs more to try and keep your water heated to a set temperature, than it does to allow it to cool and just re-heat it once.

The main difference being I can get much cheaper power between 11pm and 7am.

Speak to you power company to get switched from your existing un24 cn17/19 tariff to a un24 with a lower cost tariff running on either the ripple relay or a power company supplied timer. I dont know a whole heap of options but do know of what is called a ND16 tariff which usually gives a two register (two counters) meter with cheap power available for 8 hours and dearer power for the remaining 16 hrs (usually used on the likes of nightstore heaters). A sparky would be your only option in regards to a timer on the cylinder if it had to be mounted in the switchboard.

I have a two register smart meter. And the power company said they can give me cheaper power at night time.

If you wanna save a little bit off your power bill, could always lower your hot water temp if you have not already.

55-60C is all you need really

-Indy

I have already lowered it to the legal minimum.

Spend the money on insulation, its done in a flash. Do the ultimate job so you have no heat loss. Completly surround cylinder with wool insulation, batts if you dont mind the dust, either way wear a mask and cut the pieces and push behind, under over, all round, no gaps. Fill the whole cavity even 500mm thick is great.

Modify usage and turn down temp, I'm at 45 degrees C

Otherwise switching HW supply on and off can be done by a timer powered off the HW circuit, and not affected by ripple switching

A whole swag of polyethylene farm piping on your roof would heat a HW cyclinder on sunny days

The cylinder is relatively new, and is barely warm on the outside. It is well insulated. The piping is insulated. I can't do much more to limit heat loss.

I've investigated using solar heating - but the systems cost more than the power I would save, and hence are not worthwhile.

[Latte]

Modify usage and turn down temp, I'm at 45 degrees C

P.Dath mentioned a legal minimum, I thought it was 55^C ? 45 is a tad risky no?

[BoristheBiter]

What's involved with getting a timer put on your hot water cylinder to stop it heating during the day? I want to use cheaper night time power, 11pm to 7am.

I was thinking if they install it at the hot water cylinder it will keep getting turned off when they ripple the power off and on.

Unless you have a high use house hold, the savings would not be all that great.

For all them that say a lower temp is the answer, its not, you use more hot water to keep the same temp for showers dishes etc, the more you use the more cold that goes in so longer heating time.

If you are going though that much hot water then look at getting a bigger one or if you can go gas.

[Virago]

...Modify usage and turn down temp, I'm at 45 degrees C...

Remind me never to shake your hand...

At that temperature your HWC is a perfect breeding ground for bacteria - even 55 deg is not entirely safe. From a health point of view, it's better to store water at 65-70 deg, and use a tempering valve to bring it down to a safe temperature at the tap.