Easy Question (I hope!!) Mk Sentry Consumer Unit

[Jaroson]

Hello!!

This will, hopefully, be a really easy one!! My immersion heater does not work (the red light on the switch doesn't come on) and I am assuming that a fuse has blown in the consumer unit. I am just wanting to know how to disconnect the mains to the consumer unit and open it up to replace the fuse.

Any suggestions??

Cheers.

 

[JohnD]

Modern MK Consumer Units (usually cream in colour) do not have fuses. They have MCBs (Miniature Circuit Breakers) which have what looks like a trip switch for each circuit, that automatically goes to the "off" position when there is an overload.

With older CUs (usually brown or grey) that do have fuses in, you do not open the CU to change the fuse. There may be a hinged door; but the fuseholder pulls out. The main switch should be immediately obvious. The householder is not expected to open the CU, whether it is a fuse or an MCB.

If you can lay your hands on a digital camera and put up a pic of the CU we can tell you what sort you have.

It is fairly rare for an immersion heater to trip an MCB or blow a fuse unless it is seriously faulty. It is more likely that the switch has worn out and stopped working.

 

[delmel]

Hello!!

This will, hopefully, be a really easy one!! My immersion heater does not work (the red light on the switch doesn't come on) and I am assuming that a fuse has blown in the consumer unit. I am just wanting to know how to disconnect the mains to the consumer unit and open it up to replace the fuse.

Any suggestions??

Cheers.

I would suggest you unscrew the fused unit and check for a supply in and out voltage, it may just be the neon has packed up. I would suggest more probable this is the case and maybe your immersion heater has corroded and packed up.
This should be on its own supply ciruit and covered by one fuse or mcb within the consumer unit.

 

[RF Lighting]

Is the water still heating up?

It is reasonably common for the neon to fail on immersion heater etc switches after a good few years service.

As JohnD said MK sentry consumer units do not contain fuses, they have circuit breakers which are simply reset (rather than having to rewire a fuse)

Are all the individual MCBs in the on position?

<edit> Too slow again

 

[kai]

Have you checked the 13amp fuse inside the immersion switch itself?

Many immersion controller switches, are 13amp fuse-connection units - with a small 13amp plug top type fuse mounted behind a small hatch on the faceplate of the switch (may be retained by a small screw).

 

[Steve]

I am just wanting to know how to disconnect the mains to the consumer unit .

Dont even think about it!

 

[securespark]

Have you checked the 13amp fuse inside the immersion switch itself?

Many immersion controller switches, are 13amp fuse-connection units - with a small 13amp plug top type fuse mounted behind a small hatch on the faceplate of the switch (may be retained by a small screw).

Other immersion heaters do not have a local fuse, and are switched by a 20A DP switch.