Honeywell F&E using Nest

[bernardgreen]

Somewhat vague??? An example?

A shorted turn in a pump motor winding. Winding over heats and more turns short out, motor still runs but shorted turns increase the amount of current the motor takes.

 

[aptsys]

you should not be using 0.5mm2 on a heating system, the minimum is 0.75mm2

Nonsense

 

[ianmcd]

Nonsense

If the boiler or controls manufacturer specifies it then it has to be .

Use standard commercial cables for wiring. - Minimum cross-section of the wires: 0.75 mm2 Do not exceed the following maximum wire lengths: - Bus lines: 300 m 230 V connection lines and bus lines must be laid separately if they are longer than 10 m. The controller may only be installed in dry rooms.

 

[aptsys]

If the boiler or controls manufacturer specifies it then it has to be .

Use standard commercial cables for wiring. - Minimum cross-section of the wires: 0.75 mm2 Do not exceed the following maximum wire lengths: - Bus lines: 300 m 230 V connection lines and bus lines must be laid separately if they are longer than 10 m. The controller may only be installed in dry rooms.

The electrical installation is performed to BS7671, not the boiler or controls manufacturer.

 

[EFLImpudence]

That is true, but it does not apply to supplied appliance flexes.

Nevertheless the same rules of physics apply to them as any other conductor.

Some boiler manufacturers do indeed state that 0.75mm² flex should be used.
I don't think they said 'minimum' (can't be bothered to look again) so by the same logic - that manufacturer's instructions must be followed - 1mm² would not be allowed.
That, clearly, would be ridiculous.

The wiring regulations no longer state that MIs must be followed, but merely taken into account.