Immersion diversion advise

[Plumb Tidy]

Hi all, I'm just after some knowledge to something i came across today. I was asked how a direct unvented cylinder worked in an apartment a few doors down to where i was working. The couple just moved in and wanted some advice, They had only been in the apartment for two days and used to have a combi system. The cylinder wasn't heating up over night and they had to constantly use the boost and the controls were not working at all.

I made safe the electric and opened up the control box and saw what is in the picture attached to this thread. One wire from one RCD feeding both immersions, the controls completely by passed. I was just wondering why they had done this as i am interested. Also wanted to know if one 20amp breaker is suitable for two immersions around 3kw's each.

I have asked them to get an electrician in. Then i can sort out the cylinder as the expansion vessel is flat and the check valve is before the tee off to the cold feed to bathroom and kitchen and D1 for the expansion relief runs uphill 600mm, been there since 2001 with no paperwork.

Cheers.

 

[ShaunCorbs]

Sounds like the last people bypassed the controls as it’s bad / faulty and couldn’t be bothered to sort it

 

[Basher]

With regard to your comment about the capacity of the breaker and cable - good call - 2 x 3kW (@240V) = 25Amps, over the safe rating for 2.5 T&E, and the 20A breaker (though it might not trip)

But that Horstmann timer is designed to ensure only one immersion can be on at a time. ie if you pressed 'boost' while the lower timed immersion was on, it would disconnect the lower timed one for the duration of the boost.

If the Horstmann controller still works, and is reconnected and used as intended, the circuit won't be overloaded.

As per Shaun, looks like a bodge cos something's gone wrong. Maybe the bottom immersion has failed?