UK Off-Peak / Peak Immersion Heaters

[mattnarb]

Hi All, my flat has Off-Peak and Peak power supply and the hot water is produced via 2 immersion heaters, the bottom element is fed by the Off-Peak supply and the top one by peak (24hr) supply. As immersion heaters have a limited life span, I'd like to have more control of the Off Peak element and would like to know whether it's possible to wire the bottom immersion heater to both the Off-Peak and Peak supply so I can switch between the supply whenever necessary?

If this can be done, could the existing digital controller also be used when control the bottom immersion heater (when operating in the Peak mode)?

Thanks in advance for any help.

 

[richy3333]

~Never seen it done. The bottom immersion is for your off peak supply to heat the whole tank at a cheaper rate and the top immersion is the peak supply to 'top up' throughout he day if needed. Doing as you suggest would be very expensive if possible.

If you have PV you could use a power diverter to heat the water more cheaply

 

[mattnarb]

~Never seen it done. The bottom immersion is for your off peak supply to heat the whole tank at a cheaper rate and the top immersion is the peak supply to 'top up' throughout he day if needed. Doing as you suggest would be very expensive if possible.

If you have PV you could use a power diverter to heat the water more cheaply

Thanks. What do you mean by 'If you have PV'?

 

[richy3333]

PV - photovoltaic = solar panels

 

[mattnarb]

PV - photovoltaic = solar panels

Thanks, got it. Unfortunately don't have solar panels.

 

[suffolkspark]

Do you own the flat?

 

[mattnarb]

Do you own the flat?

Yes, but the complex's rules currently prevent a lot of changes like solar panels

 

[7029 dave]

No value add doing that at all.

 

[dropinnmonty]

Hi

I have a HW tank in a property ( to be rented, in Scotland) that has been fed from an off-peak supply, with a 24hr boost function, to a single heating element. The tank only has 1 element. A spark has been in to change over old fuse boards and provide an ECIR.

He has advised that only 1 supply can be connected to the heating element, so I've asked for that to be the off-peak. Effectively it has no 'boost' facility now, to top up HW on demand. The spark says that it is NOT OK to connect the 2 supplies to the single element, in case they ever happen to be supplying at the same time. I guess a dual-element HW tank would be the solution.

I'm just seeking confirmation that I've been given the right information.

Thanks,
Jonathan

 

[7029 dave]

Hi

I have a HW tank in a property ( to be rented, in Scotland) that has been fed from an off-peak supply, with a 24hr boost function, to a single heating element. The tank only has 1 element. A spark has been in to change over old fuse boards and provide an ECIR.

He has advised that only 1 supply can be connected to the heating element, so I've asked for that to be the off-peak. Effectively it has no 'boost' facility now, to top up HW on demand. The spark says that it is NOT OK to connect the 2 supplies to the single element, in case they ever happen to be supplying at the same time. I guess a dual-element HW tank would be the solution.

I'm just seeking confirmation that I've been given the right information.

Thanks,
Jonathan

So do you have a dedicated off peak consumer unit and a 24 hour consumer unit , another question is the hw element long top entry. Just to add the whole supply goes over to off peak so you could switch the circuit over to 24 HR supply and have it on a time clock that way you could top up if need be.

 

[dropinnmonty]

So do you have a dedicated off peak consumer unit and a 24 hour consumer unit , another question is the hw element long top entry.

Yes, a new dual-supply board has just been fitted (it has separately metred supplies). The HW element is top entry (from memory I think the element is about 40-45cm long)

 

[7029 dave]

Yes, a new dual-supply board has just been fitted (it has separately metred supplies). The HW element is top entry (from memory I think the element is about 40-45cm long)

See my edited post

 

[7029 dave]

See my edited post

The 24 HR supply (general domestic) should going over to off peak too , you say to separate meters lmo check with your energy supplier that is the case else or would mean 2 element tank and 2 circuits one off peak one 24 HR (general domestic)

 

[dropinnmonty]

The 24 HR supply (general domestic) should going over to off peak too , you say to separate meters lmo check with your energy supplier that is the case else or would mean 2 element tank and 2 circuits one off peak one 24 HR (general domestic)

A white 'flex' cable feeds the single element on the tank. It was 3 cores plus earth, so assume it had 2 lives. It comes from a point on the wall near the tank, which is back-to-back with this boost/time clock in kitchen. I'm not sure if the 2 lives feed direct from this box. Or if this only supplies the 24hr boost feed. But the fact it has a timer on it makes me think that this device could manage whether an off-peak or 24hr feed was sent to the tank (and so avoid sending 2 live feeds at the same time....which is what the electrician says needs to be avoided).

 

[7029 dave]

A white 'flex' cable feeds the single element on the tank. It was 3 cores plus earth, so assume it had 2 lives. It comes from a point on the wall near the tank, which is back-to-back with this boost/time clock in kitchen. I'm not sure if the 2 lives feed direct from this box. Or if this only supplies the 24hr boost feed. But the fact it has a timer on it makes me think that this device could manage whether an off-peak or 24hr feed was sent to the tank (and so avoid sending 2 live feeds at the same time....which is what the electrician says needs to be avoided).

Well what does your electrician say he should know he has changed the consumer units what is there to assume.

 

[oscar21]

Electrician is talking rubbish, the E7 timer instructions even mention putting a link between the off peak and on peak terminals when there is only one element.

Also how can the timer be connected to the off peak supply, the time will go wrong every time the off peak supply goes off. Needs wiring to the 24hr supply.

https://free-instruction-manuals.com/pdf/p3133739.pdf