Immersion CYLINDER and controls help

[nellystew]

My son’s just moved in to his first place (eventually!).

The hot water is done by an immersion heater with two elements and no timer that I can see.
Things i’m not sure about.

1. Is there any reason why there are two elements or is it just redundancy?

2. The two elements go back to their own fused switch, as I can’t find a timer does that mean they just need to be turned on manually and then the temperature is controlled by the red knob in the 3rd pic?

3. Can I replace the fused switches with some kind of timer(s)?

Thanks.

Here’s some pics

 

[sxturbo]

There is no reason you can't change the switches for timers

https://www.tlc-direct.co.uk/Produc...A0IQKNqPgO85VCkOsXiDOIrIf2wimngBoCRM0QAvD_BwE

Is electric emersion definitely it's primary and only source of heat? I just find it unusual to have to remember to physically turn on switches for hot water, especially bas the system doesn't look that old

 

[JohnD]

Does the home have a gas boiler?

Is the electricity supplied on an "Economy 7" type of tariff with a cheap off-peak price charged for electricity used during the night?

If so, please show the meter, and the cables and other devices around it.

 

[CBW]

• The red knob(s) look like pressure relief valves for safety as the cylinder is unvented. There doesn’t appear to be a flow/return from a boiler, so basically a direct hot water cylinder. Some new builds might have been going that way due to “no gas boilers by xx date”.
• The temperature would be controlled by the immersion heaters thermostats (usually set between 60-65 degrees Celsius).
• You can add some timers to the system, I doubt the existing will be economy 7.

 

[nellystew]

There is no reason you can't change the switches for timers

https://www.tlc-direct.co.uk/Produc...A0IQKNqPgO85VCkOsXiDOIrIf2wimngBoCRM0QAvD_BwE

Is electric emersion definitely it's primary and only source of heat? I just find it unusual to have to remember to physically turn on switches for hot water, especially bas the system doesn't look that old

Do these fit in line between the the current switches and the immersion elements?
What size flex should I use?

 

[sxturbo]

Do these fit in line between the the current switches and the immersion elements?
What size flex should I use?

Edited':

I'd advise 2.5mm flex, though you could potentially use 1.5mm but it be tight on the current rating imo. I'd rather go over kill

 

[nellystew]

Does the home have a gas boiler?

Is the electricity supplied on an "Economy 7" type of tariff with a cheap off-peak price charged for electricity used during the night?

If so, please show the meter, and the cables and other devices around it.

No gas boiler, just 3 electric heaters and a towel rail in the bathroom.

Here’s the meter and fusebox, I’ve told him to get the whole thing replaced with a new board.
The 3 circuits on the left hand board are for the heaters.

 

[nellystew]

• The red knob(s) look like pressure relief valves for safety as the cylinder is unvented. There doesn’t appear to be a flow/return from a boiler, so basically a direct hot water cylinder. Some new builds might have been going that way due to “no gas boilers by xx date”.
• The temperature would be controlled by the immersion heaters thermostats (usually set between 60-65 degrees Celsius).
• You can add some timers to the system, I doubt the existing will be economy 7.

Where should the thermostat be on the elements be?

 

[sxturbo]

Where should the thermostat be on the elements be?

Inside the grey covers, remove the screw and underneath you should see a dial and should be set between 55 and 65 degrees

 

[JohnD]

No gas boiler, just 3 electric heaters and a towel rail in the bathroom.

Here’s the meter and fusebox, I’ve told him to get the whole thing replaced with a new board.
The 3 circuits on the left hand board are for the heaters.

The cables show that both CUs are permanently live. If you change to an off-peak tariff, you could have the heaters (including the lower immersion, so it needs at least four) timed so they only come on during the off-peak period. Even if you have no immediate intention of going off-peak, it might be sensible, if you are having a new CU, to have a separate one for the heater circuits, and with extra spare positions in case you ever want more heaters.

 

[JohnD]

Do these fit in line between the the current switches and the immersion elements?
What size flex should I use?

The flex going into the immersion heaters should be heat-resistant, and probably already is, so you need not change it. It looks like butyl rubber, creamy coloured, and if you rub it with your thumb, feels rubbery.

The cable up to the flex outlet will be fixed to the wall and does not get hot, so ordinary Twin & Earth 2.5mm will be normal.

As there is no off-peak tariff, and the insulation on these modern cylinders is very good, there is not much point in splashing out on timers.

With an off-peak supply it is usual to have the entire CU timed, rather each individual circuit.

 

[sxturbo]

As there is no off-peak tariff, and the insulation on these modern cylinders is very good, there is not much point in splashing out on timers.

.

I think the idea is that they don't have to remember to switch it on every time he wants hot water, by putting it on a timer he can forget about it and have continual hot water.

It's not just about economy 7

 

[JohnD]

If he leaves it continually switched on, he will have hot water whenever he wants it, and the thermostats will turn the elements off when the water reaches the preset temperature.