Hot Water cylinder and 2x immersion heaters

[Marvo]

If both elements were running together it would take several minutes for a 16A MCB to trip at 26A load and highly unlikely that the fuse and circuit breaker would both trip together.

 

[Dave OCD]

Well in that case it can never have worked for any length of time as it's trying to draw 6kW through a 13a fuse !

 

[Dave OCD]

This needs sorting out as a matter of urgency, Shermin with all due respect I'd ask the Sparks that you're training with to have a look with you so you then understand with some confidence what needs doing.

 

[Shermin]

well certainely each element needs its own FCU and MCB, so yes get stuck in.

I will rewire it myself and then get someone from work to double check for me. I get I'm an apprentice, but gota learn some how. Thanks for your help.​

Yes

Thanks for your help. Will do this.

Well in that case it can never have worked for any length of time as it's trying to draw 6kW through a 13a fuse !

I did kinda think someone was taking the p**s outa me. I will rewire it properly.

Thanks for your help guys. Was kinda embarrassed to ask for help from the guys from work in case they torn me a new one rather than help.

 

[Shermin]

This needs sorting out as a matter of urgency, Shermin with all due respect I'd ask the Sparks that you're training with to have a look with you so you then understand with some confidence what needs doing.

Yeah I will do. Will rewire it myself and then get someone to check it out. But I take it from the pic above, that is the correct way?

 

[The Ghost]

Yeh and don't forget the cert for it afterwards. Is the Landlord ok with this? Should you not be calling them to fix it?

 

[Shermin]

Yeh and don't forget the cert for it afterwards. Is the Landlord ok with this? Should you not be calling them to fix it?

It's my own flat (with the good lady of course), so think the landlord will be ok with it.

 

[Dave OCD]

Yes the drawing is good apart from if there are two separate supplies I see no need for the boost controller or 'Control Board' as you'd have two individual supplies to two elements via independent 20a DP switches. If it's a pain to run a 2nd 2.5 from mains position you could fit a Horstmann or similar controller in the airing cupboard, the timed output is designed to coordinate with E7 times and the 'boost' function connects to the top element - all designed so both can't be energised at the same time.

 

[Leesparkykent]

It doesn't need rewiring unless the supply cable is up the swanny. A single supply from the peak board should go to the SFCU/DP switch, from the load side of the SFCU/DP switch is then connected to the LNE terminals of the controller, the bottom immersion is then connected to terminal 5 and the top immersion is connected to terminal 4. You set the off peak time on the controller which controls the bottom immersion and the boost function controls the top immersion. Unless the controller is faulty then it's impossible to turn on both immersions at the same time, hence limiting the load to 3KW/13A. Measure the impedance of the immersions, IR the immersions and check the controller is functioning correctly.

 

[Dave OCD]

I will rewire it myself and then get someone from work to double check for me. I get I'm an apprentice, but gota learn some how. Thanks for your help.​

Thanks for your help. Will do this.


I did kinda think someone was taking the p**s outa me. I will rewire it properly.

Thanks for your help guys. Was kinda embarrassed to ask for help from the guys from work in case they torn me a new one rather than help.

It shouldn't be that way, I always say to my son [and apprentice], never ever be afraid to ask anything even if you think it's trivial. With you still in your 1st year especially I'm not impressed by the sound of your 'mentors'.

 

[Shermin]

Yes the drawing is good apart from if there are two separate supplies I see no need for the boost controller or 'Control Board' as you'd have two individual supplies to two elements via independent 20a DP switches. If it's a pain to run a 2nd 2.5 from mains position you could fit a Horstmann or similar controller in the airing cupboard, the timed output is designed to coordinate with E7 times and the 'boost' function connects to the top element - all designed so both can't be energised at the same time.

The CU's are in the same cupboard next to the cylinder. About 3 metres apart.

 

[Octopus]

Sounds to me as if the controller has given up the ghost..............

Best you find the installation wiring instructions as I believe this unit relies on its own internal "clock" to switch to the lower element ....... ........ so if they are both working together its certainly not correct.

 

[Dave OCD]

But that doesn't explain both flexes connected to the load side of a single SFCU ?

 

[suffolkspark]

Dude you need 1x on peak supply cable to the timer. Each element then needs to be wired back to the timer seperately. The timer will not let both run at the same time. Do not over complicate it.

 

[Shermin]

The only place nearby to me that will sell anything readily available is screwfix.

Will this be ok?

https://www.screwfix.com/p/lap-7-day-digital-immersion-timer/1804r

 

[Shermin]

Dude you need 1x on peak supply cable to the timer. Each element then needs to be wired back to the timer seperately. The timer will not let both run at the same time. Do not over complicate it.

So if I take a supply from the 24/7 supply board, to a FCU, then to the controller, then take a separate cable to each element all should be good?

 

[Dave OCD]

No you need something like this.... sohttps://www.googleadservices.com/pagead/aclk?sa=L&ai=DChcSEwj07fv1puXaAhWDse0KHdgiBZUYABACGgJkZw&ohost=www.google.co.uk&cid=CAASEuRoS2Lx_jnX4M44ivvceFe3Dw&sig=AOD64_2ik6bvXiOkL3qpJcFec82eTrONpQ&ctype=5&q=&ved=0ahUKEwiqgPj1puXaAhXHVsAKHS0ZC0cQ9aACCDI&adurl=met

 

[Shermin]

No you need something like this.... sohttps://www.googleadservices.com/pagead/aclk?sa=L&ai=DChcSEwj07fv1puXaAhWDse0KHdgiBZUYABACGgJkZw&ohost=www.google.co.uk&cid=CAASEuRoS2Lx_jnX4M44ivvceFe3Dw&sig=AOD64_2ik6bvXiOkL3qpJcFec82eTrONpQ&ctype=5&q=&ved=0ahUKEwiqgPj1puXaAhXHVsAKHS0ZC0cQ9aACCDI&adurl=met

Thanks. I will need to see if I can find somewhere nearby that will do something similar.

 

[Shermin]

Guys just wanted to say thanks very much for all your help. I have liked everyone's post, but it doesn't really show how much I appreciate the help. Cheers again!

 

[Dave OCD]

So if I take a supply from the 24/7 supply board, to a FCU, then to the controller, then take a separate cable to each element all should be good?

I'd ditch the FCU and use a 20a DP switch, you have adequate overcurrent and short circuit protection with the 16a MCB, the DP switch is more suited to the load than a 13a fuse constantly running at full current.