Advice needed on kitchen cooker, hob and consumer unit wiringI’m currently refurbishing my kitchen and would appreciate some advice on the electrical work.
We are replacing the existing cooker with:
A built-in oven rated at 3.3 kW, with the manufacturer specifying a 16 A supply.
A separate induction hob rated at 7.2 kW, with the manufacturer specifying a 32 A supply.
A 1,000 W microwave.
I have spoken to three electricians, but their recommendations and quotes vary considerably.
Electrician 1
They said the oven and hob could both run from the existing 32 A cooker supply, subject to the appropriate diversity calculation. The existing cooker connection unit would be relocated, and the isolation switch would be moved to an accessible position because its current location would be directly behind the built-in oven cabinet.There is also an existing 16 A supply in the kitchen labelled “I/M”. I assume this may originally have been installed for an immersion heater. The electrician said this could be used to supply a socket for the microwave.
Quote: £280
Electrician 2
They said the consumer unit needs replacing because it is “from the 1970s”. However, the house was actually built in the mid-1990s. They also said the hob, oven and microwave would each require separate supplies, with the microwave requiring a 20 A supply.
Quote: £950
Electrician 3
They said the oven and hob would require separate supplies, but that the microwave could be supplied from the existing 16 A “I/M” cable.
Quote: £350–£450
The quotes and recommendations are therefore quite different. I want the work done properly and safely, but I am unsure whether replacing the consumer unit is genuinely necessary, particularly as only one electrician has recommended it.
My questions are:
Can the oven and induction hob share the existing 32 A cooker circuit after applying diversity?
Is a dedicated 20 A supply really necessary for a 1,000 W microwave, or could it be connected to a suitable 13 A socket or fused spur?
Can the existing 16 A “I/M” circuit safely be repurposed for the microwave, assuming it is tested and suitable?
Is a new consumer unit required, or should this depend on its condition, RCD protection, available capacity, earthing and test results rather than its age?
Are these quotes broadly reasonable for the work described?
Any advice from qualified electricians or anyone who has had similar work carried out would be appreciated.
We are replacing the existing cooker with:
A built-in oven rated at 3.3 kW, with the manufacturer specifying a 16 A supply.
A separate induction hob rated at 7.2 kW, with the manufacturer specifying a 32 A supply.
A 1,000 W microwave.
I have spoken to three electricians, but their recommendations and quotes vary considerably.
Electrician 1
They said the oven and hob could both run from the existing 32 A cooker supply, subject to the appropriate diversity calculation. The existing cooker connection unit would be relocated, and the isolation switch would be moved to an accessible position because its current location would be directly behind the built-in oven cabinet.There is also an existing 16 A supply in the kitchen labelled “I/M”. I assume this may originally have been installed for an immersion heater. The electrician said this could be used to supply a socket for the microwave.
Quote: £280
Electrician 2
They said the consumer unit needs replacing because it is “from the 1970s”. However, the house was actually built in the mid-1990s. They also said the hob, oven and microwave would each require separate supplies, with the microwave requiring a 20 A supply.
Quote: £950
Electrician 3
They said the oven and hob would require separate supplies, but that the microwave could be supplied from the existing 16 A “I/M” cable.
Quote: £350–£450
The quotes and recommendations are therefore quite different. I want the work done properly and safely, but I am unsure whether replacing the consumer unit is genuinely necessary, particularly as only one electrician has recommended it.
My questions are:
Can the oven and induction hob share the existing 32 A cooker circuit after applying diversity?
Is a dedicated 20 A supply really necessary for a 1,000 W microwave, or could it be connected to a suitable 13 A socket or fused spur?
Can the existing 16 A “I/M” circuit safely be repurposed for the microwave, assuming it is tested and suitable?
Is a new consumer unit required, or should this depend on its condition, RCD protection, available capacity, earthing and test results rather than its age?
Are these quotes broadly reasonable for the work described?
Any advice from qualified electricians or anyone who has had similar work carried out would be appreciated.
