Off peak heating

[studentspark]

Unoccupied small flat has a 6 way 3036 CU

It also has a 4 way 3036 CU for off peak heating.

Only the CU's are visible service head and meter in some other part of the building, as yet to be found.

Would appreciate some insight how this may be wired.

The heaters are storage heaters. which will charge up over night, but with this set up I presume can't be turned on during the day (If all heat has gone)

Was that common for this form of heating.

Would like to change the 6 way CU and leave 4 way as is..

I don't think it applies in this situation but it got me thinking, if the power to the storage heaters was switched between two CU's for peak off peak, would upgrading one CU and not the other cause issue. Don't think so , but thought I would ask.

 

[flameport]

The heaters are storage heaters. which will charge up over night, but with this set up I presume can't be turned on during the day (If all heat has gone)

That's how they work. Even a new installation would be the same - storage heaters are never wired so they can be turned on in the daytime.
If all the heat has gone before the next recharge cycle, then either the heater is too small, the building needs more insulation, or something is wrong with the heater (broken elements / defective thermostat etc.

Replacing one CU and not the other won't be any problem, and the heaters won't be switched between one and the other either - it will be normal radial circuits from the heater CU only.
The only exception is where dual purpose heaters are fitted, which have an additional convector heater built in for daytime use, or some had a fan built in. These will have 2 supplies, one for the night charging and another one for the daytime part.

However if replacing one CU, why not do both at the same time - particularly if the place is unoccupied.

If replacing the heater board, DO NOT rely on the power being off in the daytime when replacing - the incoming supply must be isolated properly.

 

[sparkticus]

If replacing the heater board, DO NOT rely on the power being off in the daytime when replacing - the incoming supply must be isolated properly.

Yes, some are on time clocks which may not be set correctly allowing the CU to become live just as you grab the busbar. Some are on radio switches with on/off times transmitted on one of the radio channels (can't remember which one)

Also, you may not be able to perform live testing on an off-peak circuit unless you go there at night/early morning so you need to consider all dead tests carefully and use (R1+R2) + Ze for Zs. You need to find the meter cupboard anyway to allow you to find out what earthing arrangement you have. Might as well do that sooner rather than earlier.

 

[Taylortwocities]

Dear studentspark ( and with respect).

Is this for your own flat? If so we can assist. This is a DIY forum.

If it is for someone else, then you obviously do not have the competence to do the work, so leave it.