Advice on meters, timers, thermostats

[Noidea88]

Hello.

I have the following meter-

Meter type: Smart (SMETS2)
Aclara: SGM1416B

The booster is a Electrisaver Electronic Timer; Horstmann

I was told by the engineer who was servicing my Heatrae Sadia Megaflow
tank that the booster Electrisaver Electronic Timer; Horstman is faulty and needs to be looked at.

The engineer also noticed an issue with the cabling - ' all consumer tails undersized other than
netural should be 25mm to match incoming 100A fire.' so in other words the lower gray cables should be a
22-24 thickness which is now standard.

I feel this may cause future issues and probably needs to be addressed?

Idealling I would like a working timer

I feel that the thermostate is in built into the heat tank where it regulates the temperature. A separate unit
where I can regulate the temperature would be ideal.

Before I contact electricians looking for quotes I am trying to educate myself on what I have and the restrictions
laid against me.

I have a strong feeling that I need to get the tails fixed/looked at?
I want a thermostat
I want a working timer

With the Heat Sadia Megaflow I am thinking is it best to go with one of their own products ie thermostate panel like timer or
go with whatever the engineer recommends?

 

[EFLImpudence]

' all consumer tails undersized other than netural should be 25mm to match incoming 100A fire.'

Not 100% sure what that means.

Are you sure the fuse is actually 100A or is that the maximum capacity of the holder?

If it is 100A then the tails - both Line and Neutral - should be 25mm².

so in other words the lower gray cables should be a
22-24 thickness which is now standard.

Not sure what that means either.

25mm² is the cross-sectional area of the copper conductor.

 

[endecotp]

I feel that the thermostate is in built into the heat tank where it regulates the temperature. A separate unit
where I can regulate the temperature would be ideal.

That's not common. Why do you want to be able to frequently change the temperature of the water coming from your hot taps? That's what a mixer tap is for, you mix hot and cold water to get what you want.

Note that there is a limit on the minimum temperature because of Legionella. It must be above 60 C to kill any bacteria.

 

[Murdochcat]

Do you actually know what size the main fuse is ?

 

[ericmark]

So there is a timer, so the bottom immersion heater is only activated when your meter shows you are on off-peak power, and there is a thermostat, so the bottom immersion heater is set hotter to the top one, so under normal conditions the top one will not switch on, it will only switch on when a lot of DHW has been used.

The timer is also designed, so both immersion heaters can't turn on together.

It is common to have separate distribution units for peak and off-peak, and for the meter to do the timing. And there are many alternative ways to basic get the same thing. My smart meter only has one output, as I have no option to let the meter do the timing, but yours does, but it does not mean the second output is used.

 

[CountryFan]

@Noidea88 - can you post a photo of the plywood board and components on it?

 

[morqthana]

 

[ericmark]

Very funny, but we in the electrical trade know a board has to be provided for the supplier to attach their equipment to, be it at the back of the meter cupboard

or on the wall inside the house, there should only be the supplier's equipment on it, but I know mine has my consumer units as well.

It would seem many are looking at off-peak at the moment, likely due to turn off of radio 4 long wave, clearly not in this case, as already a smart meter, and the Economy 7 has causes a lot of problems, as it is a tariff, not a system, and it is so easy to jump in with incorrect advice, as we have assumed, and assumed wrong.

I also assumed with water heating, I assumed cheaper to use oil, and that it cost a fortune to heat water. I found out in real terms I am using around 2.5 kWh per week to heat the water, so less than a £1 with most tariffs, so not worth spending much to reduce costs.

I found one of these

at nearly £50 second hand on an internet search, that seems well overpriced. The instructions show rather a simple wiring diagram, it does not seem to have two supplies. However, no harm making sure first. It would seem we are looking at a pre-pay Economy 7 system, but the meter has a dual output, which does not seem to make sense with the switch shown, so asking for more information makes a lot of sense.

 

[CountryFan]

View attachment 381387

Not sure what you’re getting at

 

[morqthana]

Not sure what you’re getting at

When you wrote this:

@Noidea88 - can you post a photo of the plywood board and components on it?

There had been no mention of a plywood board. Or indeed any type of board.

 

[CountryFan]

When you wrote this:



There had been no mention of a plywood board. Or indeed any type of board.

Yes, but when I look at the original image posted, there’s a plywood board next to the unvented cylinder. If I zoom in I can see what looks like a 100A fuse/carrier, so it’s me who mentioned the plywood board but the OP who posted the photo first.

 

[morqthana]

My bad - I hadn't clicked on the image, and as you say there is a ply/OSB board there with a fuse.

Sincere apologies for my somewhat sarky post.

 

[ericmark]

I have no idea why @Noidea88 would post on two forums, then vanish? Been around since 2024 seems that tank is drained in the winter. So we must consider that the immersion heaters could be damaged.

Looking at the distance between the two immersion heaters, they seem too close to be a bath/sink arrangement. So would need to be a dual supply of some type, be it peak/off-peak, or some solar system, but since it seems in a flat, most likely is the peak/off-peak.

As to how this is controlled, the E15 in the part number seems to relate to time, so 15 minutes, ½ hour, and one hour as the E30 is ½ hour, 1 hour, and 2 hours. I will guess on around 150 litres, so around the 12 kWh mark to heat the whole tank. So looking at around 4 hours to heat the whole tank, so one hour seems rather a short time. Clearly hoping not starting with a cold tank.

So this timer

which can time to 4 hours, but still starts at 15 minutes, and is far cheaper at £26 seems best like for like replacement.

But does anyone expect a reply.

 

[JohnW2]

Looking at the distance between the two immersion heaters, they seem too close to be a bath/sink arrangement. So would need to be a dual supply of some type, be it peak/off-peak, or some solar system, but since it seems in a flat, most likely is the peak/off-peak.

Yes, possibly.

If there were a solar system, but no batteries, and if the solar system could (at least sometimes) provide more than 3 kW, it might perhaps just be a way of essentially 'increasing the size/power of the immersion(s)' - so that more than 3 kW of solar-generated power could be used to heat the water?

 

[ericmark]

If there were a solar system, but no batteries, and if the solar system could (at least sometimes) provide more than 3 kW, it might perhaps just be a way of essentially 'increasing the size/power of the immersion(s)' - so that more than 3 kW of solar-generated power could be used to heat the water?

That does not tie in with a simple boost timer.

It will be interesting if @Noidea88 ever replies to see how close I am.