What is a Service Head?

What Is a Service Head? Whose Job Is It to Fix or Replace?

Quick answer:

A service head is the point where the electricity network's cable enters your property and connects to your meter and consumer unit.
It belongs to your electricity distribution network operator (DNO) — for us that's UK Power Networks (UKPN) — not to you or your electrician.
If it's warped, blackened, or leaking black tar, call UKPN free on 105. They replace it at no cost.
Electricians can't legally touch the service head itself, but we're often the ones who spot the problem and point you the right way.

Whose Responsibility Is the Service Head — Yours or the Network Operator's?

This is the bit that catches people out, and it's the reason we've written this page. The service head, the fuse inside it, and the cable running up to it are owned and maintained by your DNO, not by you.

In our patch across Kent and East Sussex, that's UK Power Networks. It doesn't matter whether you own the freehold, you're a landlord, or you've got a maintenance contract with an electrician — nobody except the DNO is permitted to open or work on that fuse. It's sealed for a reason: it's still live even when your consumer unit is switched off.

That matters for your wallet as much as your safety. We get calls asking for a quote to "fix the fuse box outside," and if that fuse box turns out to be the service head, there's nothing to quote — it's a free call to UKPN, not a paid job for us.

Where Will You Find the Service Head in Your Property?

Location varies with the age and type of building:

Most houses: in an external meter box on an outside wall, or just inside the front door in an under-stairs cupboard.
Older properties: sometimes in the cellar.
Flats and apartment blocks: often grouped together in a communal meter cupboard.

If you're not sure which box is which, a quick video call with one of our electricians is usually enough for us to identify it from a couple of photos, without you needing to book a site visit.

What's Inside the Setup, From the Service Head to Your Consumer Unit?

Service head fuse — the network's protective fuse, sealed and DNO-owned.
Electric meter — could be an older mechanical dial, a newer grey electronic meter, or a smart meter feeding you real-time usage data.
Isolator — a safety switch, often fitted alongside newer meters, that lets you cut power to the consumer unit for maintenance or in an emergency.
Consumer unit — your fuse board. It takes power from the isolator and splits it into the circuits running round your property. The cables in are secured with fire-rated glands so they can't be pulled loose and can't feed a fire if something goes wrong upstream.

If your consumer unit is old, undersized, or missing modern protection like RCBOs, that's a separate job — and one we can help with. See our guide on how do I know if I should change my board.

What Should You Do If the Service Head Looks Damaged?

Signs to look out for:

The casing is warped, cracked, or scorched.
The area looks blackened or sooty.
Black tar-like residue is oozing down the cable or onto the wall below.

Any of these means the fuse has overheated or failed internally. Don't touch it, and don't wait — it's a fire risk.

Call UK Power Networks free on 105. They'll send an engineer out to repair or replace the service head, and there's no charge to you for this, whoever you are or whoever owns the property.

Can Bright Spark Fix or Replace a Service Head?

No — and no electrician legally can, because it's not our equipment to work on. What we can do is:

Confirm over a phone or video call whether what you're looking at is actually the service head, or something on your side of the meter that we can fix.
Attend in person if you'd rather have someone look before you call UKPN.
Pick up any related work on your side of the meter once the DNO has sorted the service head — for example, if the isolator, meter tails, or consumer unit connections need checking afterwards.

Send us a photo and we'll usually be able to tell you straight away whether it's a 105 call or a job for us.

FAQs

Is the service head fuse the same as my consumer unit fuses?

No. The service head fuse belongs to the network and protects their cable. Your consumer unit fuses or breakers protect your own circuits and are your responsibility.

Can I replace the service head fuse myself if I know how?

No. It's sealed by the DNO and remains live at all times, even with your consumer unit off. Only DNO engineers are authorised to work on it.

Will I be charged for a service head replacement?

No. UKPN (or your local DNO) replaces damaged service heads free of charge, regardless of who owns the property.

What number do I call for a damaged service head in Kent or East Sussex?

Call UK Power Networks free on 105. If you're unsure whether the fault is on their side or yours, call us first on 01892 531 728 and we'll help you work it out

Not Sure If It's the Service Head or Your Consumer Unit?

Send us a photo, or book a video call, and we'll tell you straight away whether it's a free call to UKPN or something we should come and look at.

Call 01892 531 728 or email karen@brightsparkelectrician.co.uk

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