Attaching a timer to a Storage Heater

[stem]

As @JohnW2 has already pointed out. If the supply from the wall switch that you are proposing to wire the timer into, is controlled via a dedicated 'off peak' supply, then the power supply to it will be lost during the day, so the timer won't have any power and will stop. Some timers do have battery back up, but they are designed to for use during a brief power cut, not daily use.

 

[Hedgehog77]

Unless there it one on the market that comes with a rechargeable battery back up which will keep the settings and then recharge the battery every night. Needs to be a long lasting battery! mmmmmm Think i might be asking too much...

stem: oops, Just noticed you posted that there isn't one on the market.

Thanks all for your help. Will hopefully be changing all the storage heaters for something else at the end of the year so i guess it's a short term problem.

 

[stem]

A better alternative is to have a timer running from the permanent electricity supply. The timer then switches a relay that is wired into the off peak supply to the heater. With this scenario, you could use a WiFi switch instead of a timer.

What about the other storage heaters, don't you have three?

 

[Hedgehog77]

I do have 3 but the one in hallway at the bottom of stairs throws out enough heat for what i need really. So was think about just the one to be honest but if it's all 3 then even better.

 

[stem]

What I suggested would just operate the single heater as per your sketch. Although it would be possible to mount a three pole contactor next to the consumer unit that would switch all three heaters. I wouldn't recommend it for a DIY project though, you would need to be electrically competent to do it. Although it wouldn't be a big job though for someone that was.

EDIT
Here's a sketch showing what I mean:

 

[Hedgehog77]

Thanks so much stem.
Defo worth me thinking about the 3 pole connector. Thanks for the diagram.

 

[seasickstevie]

Contactor

 

[JohnW2]

As @JohnW2 has already pointed out. If the supply from the wall switch that you are proposing to wire the timer into, is controlled via a dedicated 'off peak' supply, then the power supply to it will be lost during the day, so the timer won't have any power and will stop. Some timers do have battery back up, but they are designed to for use during a brief power cut, not daily use.

Unless there it one on the market that comes with a rechargeable battery back up which will keep the settings and then recharge the battery every night. Needs to be a long lasting battery! mmmmmm Think i might be asking too much...

Actually, on reflection, I think that most of the electronic 7-day wire-in 'immersion timers' would work OK. I have used several of these (click here) - or, at least, older versions thereof. As you will see, the internal rechargable battery is said to give 720 hours 'cover' during power loss. The battery may not be man enough to work the relay, but so long as one made sure that the 'switch on' time was after the start of the E7 period (and the switch-off time before the end of that period), the mains supply would be present by then - so all the battery (which would be 'on charge' for 7 out of every 14 hours) would be having to do would be to keep the clock going continuously.

I would personally be inclined to give that a go - and, as the OP has suggested, it could be simply wire intoi the feed to (one) heater (but the other heaters would all have to be switched off whilst the OP was away). That would certainly be simply for him than using a contactor.

Kind Regards, John

 

[Hedgehog77]

Thanks JohnW2

I've actually got a very similar version sitting at home unopened. https://tinyurl.com/ybpq59mv

As this is 16amp then 'it should' be ok, load wise, to wire to a, I think, 3.4kw heater.

I may well give it a go and cut the wire between the heater and the wall switch and wire this in between.

The other 2 heaters will be turned off at the wall socket (fused spur) that they are wired into.

I'd clearly test this when I am at home!

 

[bernardgreen]

The option of using a contactor is a good one.

It is physically possible to fit a DIN rail single pole contactor into a consumer unit to control the supply to all MCBs.

Whether it is compliant with latest regulations / type approval of the CU I do not know.

 

[JohnW2]

Thanks JohnW2 I've actually got a very similar version sitting at home unopened. https://tinyurl.com/ybpq59mv As this is 16amp then 'it should' be ok, load wise, to wire to a, I think, 3.4kw heater.I may well give it a go and cut the wire between the heater and the wall switch and wire this in between.

Yes, that's almost identical to the ones I have and, as you say, would be OK for a 3.4kW heater.

I'd clearly test this when I am at home!

Indeed! I'm not sure how charged the battery would be 'out of the box', so you may need to initially set it up (programme it) during the night hours, when it would have some mains electricity!

The other 2 heaters will be turned off at the wall socket (fused spur) that they are wired into.

Do you mean that ("fused spur") literally? As you have been told, an FCU should not be used >13A (and, in any event, cannot have a fuse >13A) - one would normally expect just a (probably 20A) switch.

Kind Regards, John

 

[stem]

The advantage of the WiFi switch would be that you could leave the heating off for 3 / 4 weeks to match your work commitments; the timeswitch only covers a 7 day period. The disadvantage of the WiFi switch is that you need to remember to switch in on!

 

[JohnW2]

The advantage of the WiFi switch would be that you could leave the heating off for several weeks, the timeswitch only covers a 7 day period. The disadvantage of the WiFi switch is that you need to remember to switch in on!

Yes, I agree with all that - but the OP had said that 'every Thursday night' would be an acceptable option for him - and it certainly would be the simplest solution for him to implement (and, as you say, one which does not require any action on his part).

Kind Regards, John

 

[Hedgehog77]

Sorry JohnW2. No idea why i wrote fused spur.... just meant Wall switch...

Think the every Thursday night is the way froward.. Thanks for your advice JohnW2.

thanks everyone.

 

[JohnW2]

Sorry JohnW2. No idea why i wrote fused spur.... just meant Wall switch...

Fair enough.

Think the every Thursday night is the way froward.. Thanks for your advice JohnW2. thanks everyone.

You're welcome. Remember to program it so you're sure that it will switch on after the start of the cheap-rate period and switch off before the end of that period. Also, ideally, initially programme t during the cheap rate hours.

Kind Regards, John