Hello from the West Midlands

[Stig]

Something I am trying to work out is whether each storage heater needs 1 cable or 2. I don't have experience of these sorts of heaters and there seems to be conflicting info online.

Are there any benefits to the more modern storage heaters or should I look to get older second hand units and refurbish them?

Thanks for all the help

I guess two cables would be one for Economy7 and one for daytime? I've just wired one to my storage heater (old one from Ebay). Beware of modern storage heaters that have so-called 'smart' controls, if you're wiring it up to a PV diverter then you want something basic with no electronics in it.

I should have clarified, my storage heater (1.6kW) is wired directly from the second output of my PV diverter so it gets what's 'spare' once the hot water tank is up to temperature. As the PV diverter's output is variable it can only drive a simple resistive load. I don't have a TOU tariff like Joe.

[cojmh]

Re storage heaters, no need to make it complicated! So long as you have a TRV in the room with the storage heater the radiator on the central heating will adjust for the additional heat source. This can be a basic "analogue" one such as a TRV4 or a smart system such as Tado/Hive.

There are several ways to wire up a SH. IMO the best way is to site the solar diverter next to your CU (or somewhere else unobtrusive) then run a wire from there to the heating side of the SH and connect up the control side of the SH to your normal sockets circuit. You can connect the SH to a single power supply and rely on the onboard timer for traditional Ecconomy7 usage, but that isn't what we're doing here!

Makes complete sense .... I already have the TADO TRVs on all but one radiator (still have the old logic of one radiator not being on a TRV to prevent everything being potentially shut off at once - not sure if this still holds true?)

In terms of storage heaters (with the aim to get away from gas almost 100%) would it be excessive to have:

• One SH per bedroom - sized to match volume

• One SH for the living room/dining room (open plan)

• One SH for the entrance hall/stairs/landing

So basically 6 storage heaters at the moment - possibly another for the extension in the future?

Naturally it is no great loss if I put the wires in and they don't all get used.

Thanks for all the help and guidance so far

[Joeboy]

Re storage heaters, no need to make it complicated! So long as you have a TRV in the room with the storage heater the radiator on the central heating will adjust for the additional heat source. This can be a basic "analogue" one such as a TRV4 or a smart system such as Tado/Hive.

There are several ways to wire up a SH. IMO the best way is to site the solar diverter next to your CU (or somewhere else unobtrusive) then run a wire from there to the heating side of the SH and connect up the control side of the SH to your normal sockets circuit. You can connect the SH to a single power supply and rely on the onboard timer for traditional Ecconomy7 usage, but that isn't what we're doing here!

Makes complete sense .... I already have the TADO TRVs on all but one radiator (still have the old logic of one radiator not being on a TRV to prevent everything being potentially shut off at once - not sure if this still holds true?)

In terms of storage heaters (with the aim to get away from gas almost 100%) would it be excessive to have:

• One SH per bedroom - sized to match volume

• One SH for the living room/dining room (open plan)

• One SH for the entrance hall/stairs/landing

So basically 6 storage heaters at the moment - possibly another for the extension in the future?

Naturally it is no great loss if I put the wires in and they don't all get used.

Thanks for all the help and guidance so far

You will know your own upper limit for SH (our happy place is 5 (4.25kW) with a 32kWh storage capacity), just wire as if they are going in anyway then install in the most effective spots to balance with your generation or how far you are happy to go buying from the grid?

[Countrypaul]

The Eddi gives you more options, there are 2 outputs normally used for immersion heaters - however, only one can be active at a time, but you can also add a relay card to the Eddi. The relay card supports 2 relays each of which can control upto 16A. The Eddi also has a buit in timer so things can be turned on at preset times such as during the E7 period.

Have a read of the Eddi manual as it gives quit a few examples of different configurations - it s avaialbe online if you have not yet got your unit.

[cojmh]

As stig says, one cable is to the 24hr peak rate and the other is to the off peak storage. Essentially an on demand resistive heater or a set of 850W storage elements.

I have both types with our without the 24hr resistive elements. I have also found that 2x850W storage elements is good to bring the background temp up. Three elements and you Really feel the rise in a room. Welcome onboard!

All my storage heaters are on Hive smart plugs so I can set timers to coincide with TOU tariff low cost window or I can manual override specific heaters and bring them on if we have a huge solar day. Works well along with the woodstove and the GCH remains off.

Thanks for the welcome .....

I have to admit your setup from what I have read is very interesting.

I have a collection of Kasa plugs (TP Link) for various automation tasks ... So I am thinking of extending that to cover storage heaters in the future when I have the right tariff and infrastructure in place.

I understand how to do the charging automatically ... But I am less sure on how the heat discharge works (I am aiming for older simpler units with little to no electronics). Do you have the units set to a particular discharge rate all the time or do you adjust this daily depending on what you want in each room?

Whatever I install I need to ensure is as hands off as possible for other residents as possible otherwise it will not achieve the savings aims I am hoping for.

Hopefully that makes sense

[cojmh]

The Eddi gives you more options, there are 2 outputs normally used for immersion heaters - however, only one can be active at a time, but you can also add a relay card to the Eddi. The relay card supports 2 relays each of which can control upto 16A. The Eddi also has a buit in timer so things can be turned on at preset times such as during the E7 period.

Have a read of the Eddi manual as it gives quit a few examples of different configurations - it s avaialbe online if you have not yet got your unit.

I might be getting a little ahead of myself ....

Unit has shipped so I hope to get it this week .... But so far only skimmed the technical/general layout ... I will have a proper look of the manual now

[Joeboy]

As stig says, one cable is to the 24hr peak rate and the other is to the off peak storage. Essentially an on demand resistive heater or a set of 850W storage elements.

I have both types with our without the 24hr resistive elements. I have also found that 2x850W storage elements is good to bring the background temp up. Three elements and you Really feel the rise in a room. Welcome onboard!

All my storage heaters are on Hive smart plugs so I can set timers to coincide with TOU tariff low cost window or I can manual override specific heaters and bring them on if we have a huge solar day. Works well along with the woodstove and the GCH remains off.

Thanks for the welcome .....

I have to admit your setup from what I have read is very interesting.

I have a collection of Kasa plugs (TP Link) for various automation tasks ... So I am thinking of extending that to cover storage heaters in the future when I have the right tariff and infrastructure in place.

I understand how to do the charging automatically ... But I am less sure on how the heat discharge works (I am aiming for older simpler units with little to no electronics). Do you have the units set to a particular discharge rate all the time or do you adjust this daily depending on what you want in each room?

Whatever I install I need to ensure is as hands off as possible for other residents as possible otherwise it will not achieve the savings aims I am hoping for.

Hopefully that makes sense

The older units are poorly insulated and leak heat (for this reason I like them as its an ambient feel), the output control is a flap on top of the insulated box within. I have two which output controls are set all the way down so just leak heat, one is set with the flap bouncing so leaks heat quicker and the other two are automatics with a bi metal strip that I think opens a flap but not opened up to inspect as they worked fine. None of my SH's are cold by the time the charging cycle rolls around again. Personally I find them to be an outstanding bit of kit who's use solar PV has extended as has app controlled switches. I think The Wombles would approve.

[Joeboy]

I wasn't accurate, the SH that I thought was slightly open is in fact full cranked to the max output. It stopped its 5 hour charge at 02.30hrs and as you can see is still toasty. Its a 2 element 1.7 kW unit



It's also unobtrusive.



One thing we all have in common here (apart from being excellent) is that no two systems are the same. We've all got different needs and wants. Looking forward to seeing how you get on (we like photos).

[Stinsy]

Re storage heaters, no need to make it complicated! So long as you have a TRV in the room with the storage heater the radiator on the central heating will adjust for the additional heat source. This can be a basic "analogue" one such as a TRV4 or a smart system such as Tado/Hive.

There are several ways to wire up a SH. IMO the best way is to site the solar diverter next to your CU (or somewhere else unobtrusive) then run a wire from there to the heating side of the SH and connect up the control side of the SH to your normal sockets circuit. You can connect the SH to a single power supply and rely on the onboard timer for traditional Ecconomy7 usage, but that isn't what we're doing here!

Makes complete sense .... I already have the TADO TRVs on all but one radiator (still have the old logic of one radiator not being on a TRV to prevent everything being potentially shut off at once - not sure if this still holds true?)

In terms of storage heaters (with the aim to get away from gas almost 100%) would it be excessive to have:

• One SH per bedroom - sized to match volume

• One SH for the living room/dining room (open plan)

• One SH for the entrance hall/stairs/landing

So basically 6 storage heaters at the moment - possibly another for the extension in the future?

Naturally it is no great loss if I put the wires in and they don't all get used.

Thanks for all the help and guidance so far

Nothing wrong with that plan. If it were me I would go for:

• One SH for the living room/dining room (open plan)

• One SH for Downstairs hallway

• One SH for Upstairs landing

I'd then use Gas for the rads under each window. There will be plenty of days when your big 10kWp-ish solar array produces enough electric to keep your SHs charged with all the heat you'll need while the weather is still cold enough that you need the heat. But there will also be lots of days in December/January when you'll generate little-if-any electric, so you will rely on ToU electric if it is available...

Another thing to think about is air-to-air heat pump. This is basically an AC that can work in reverse.

[Fintray]

It's also unobtrusive.

And good for keeping those reds at a nice drinking temperature.