ComGas carries out full and partial rewires for homes across Farnham, Guildford and the surrounding area, from whole-house rewires in older properties to extension and renovation wiring phased around an occupied household. Every rewire is tested and certified on completion to BS 7671, the 18th Edition wiring regulations.
Knowing whether a house genuinely needs rewiring — or just targeted remedial work.
Not every wiring concern means a full rewire. Cloth-insulated or rubber-insulated cable, wiring colours from before the 2004 harmonised colour change, no earth conductor present on lighting circuits, or a pattern of C2 observations across multiple circuits on an electrical safety report are all genuine indicators that a rewire is the sensible option rather than repeatedly patching individual faults. A single faulty circuit, or a board that needs upgrading on its own, is a different job.
We look at the actual evidence — cable type, circuit age, the condition and number of existing circuits, and what an inspection has found — before recommending a rewire. Where targeted remedial work genuinely covers what's needed, that's what we propose; a rewire isn't the default answer to every wiring question.
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How we plan and carry out a rewire
Full or partial, occupied or empty, alongside other building work.
A rewire is planned around the property and the household using it, whether that means a whole-house rewire in an empty property or a phased partial rewire around a family still living there.
Full & Partial Rewires
A full rewire replaces the entire fixed electrical installation; a partial rewire addresses specific circuits, rooms or floors where the rest of the installation is genuinely sound.
Full rewires typically apply to older properties where the cable type, earthing arrangement or circuit age is out of step with current practice throughout
Partial rewires cover specific circuits or areas — a single floor, a kitchen, a loft conversion — where the remainder of the installation doesn't need disturbing
The scope is set from what an inspection or survey actually finds, not assumed from the age of the property alone
Either way, the work is tested and certified to BS 7671 on completion
A rewire in a home people are still living in needs a plan for access, temporary power and disruption before work starts, not just a list of circuits to replace.
Rewires phased room by room or floor by floor so parts of the house remain usable throughout
Temporary lighting and power arrangements agreed for rooms out of action during their phase
Access and timing discussed at survey stage around the household's actual routine, not a generic schedule
Kitchens, bathrooms and areas needing continuous services planned to minimise the time they're without power
Rewiring alongside renovation or extension work has a different rhythm to a standalone rewire, because the electrical first fix has to fit around the building programme rather than the other way round.
First-fix wiring completed before plastering, with sign-off before walls and ceilings close up
New circuits for extensions checked against the existing consumer unit's spare capacity before being added
Sequencing agreed with the wider building programme so access and timing don't conflict with other trades
Second fix — sockets, switches, fittings — completed once decoration is ready for them
Cable routes in solid walls need to be chased in, and it's worth being clear from the outset about where our work ends and where a decorator's or plasterer's begins.
Cable routes chased into walls where surface routing isn't practical or acceptable, and channels filled to a plasterable finish
We don't carry out plastering, painting or final redecoration — that's outside our scope and best left to a decorator once the electrical work is signed off
Chasing routes and outlet positions agreed with you in advance so redecoration can be planned around them
Floor and ceiling access for cable runs restored to a safe, functional state, not a decorated finish
The signs that a rewire is genuinely needed — and the signs it isn't.
The strongest indicators that a full rewire is the right answer are things you can point to directly: cloth or rubber-insulated cable rather than modern PVC, wiring colours from before the 2004 harmonised colour scheme, circuits with no earth conductor at all — common on older lighting circuits — or a consumer unit report showing repeated C2 observations spread across several different circuits rather than one isolated problem. Any one of these on its own is worth investigating properly; several together usually point toward the whole installation being due for renewal rather than one circuit at a time.
What doesn't automatically mean a rewire is needed: a single failed socket or switch, one circuit tripping repeatedly while the rest of the house behaves normally, or an old-looking consumer unit on an otherwise sound and recently-checked set of circuits. These are targeted problems with targeted fixes. We say plainly which situation we're looking at before recommending anything, because a full rewire is a significant undertaking and shouldn't be proposed as the default answer to a single fault.
Cloth or rubber-insulated cable and pre-2004 wiring colours are strong indicators a rewire is due
No earth conductor on lighting circuits is a common finding in older homes
Repeated C2 findings across multiple circuits point to the installation as a whole, not one fault
A single faulty circuit or accessory is a targeted repair, not a rewire
Reviews from real ComGas customers, shown as submitted through Google.
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Lucie Victoria
15 May 2025
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Excellent service, highly recommend
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James Mowat
30 April 2025
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Incredible service — problems fixed perfectly once again.
Lee, Paul and the team at COMGAS are fantastic. They arrived on time and got straight to work, quickly identifying the root cause of the plumbing and heating issues I was experiencing.
The problems were diagnosed swiftly, I was kept fully informed throughout, and both issues were fixed with impressive speed and precision.
Having worked in the industry for nearly 20 years, I know how rare it is to find reliable, trustworthy, and genuinely skilled professionals — let alone a team this good.
I joked about it at the time, but it’s true: I had the best shower I’ve ever had in this house after they finished the job — and I’ve lived here for 10 years!
I honestly couldn’t ask for more and can’t recommend COMGAS highly enough.
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Faz
31 March 2025
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ComGas replaced my boiler and water tank at short notice. So glad i used them. Thank you
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Laura Andrews
26 March 2025
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Lee came out to the school I work in to look at a problem with our heating, he diagnosed the issue and was able to fix it on the spot in a neat and tidy manor. Would highly recommend
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Chloe
26 March 2025
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I recently used Comgas for a gas and heating service, and I couldn't be more impressed! From start to finish, their team was professional, friendly, and highly knowledgeable. They quickly identified the issue with my heating system and explained everything in detail, offering both short- and long-term solutions.
The technician was punctual and took extra care to ensure everything was running smoothly. I really appreciated their attention to detail and how they made sure to clean up after the work was completed. My home is now warm and cozy, all thanks to their expert service. I highly recommend Comgas for anyone looking for reliable, efficient, and trustworthy gas and heating professionals!
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Bec Newey
8 July 2024
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Messaged Lee on a Sunday evening with request. Instant reply that evening and engineer came next day. Polite, professional and helpful. Thorough investigation and speedy resolution to a leak with sink in wc. Happy customer.
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P Duffy
2 April 2024
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Scott and the team have served me well over several years. Skilled craftsmen. Dependable careful and very cosy-effective. I highly recommend them.
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Cilla Trout
22 March 2024
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Definitely recommend friendly reliable service
Scott was helpful and reassuring regarding our boiler answered our concerns and explained the problem and best course of action thank you for your advice
Rewiring questions
Frequently asked questions.
If an inspection has flagged your wiring, or you're planning a renovation and want to know whether a rewire makes sense, get in touch and we'll assess it honestly.
Look for cloth or rubber-insulated cable, pre-2004 wiring colours, missing earth conductors on lighting circuits, or a report showing repeated significant findings across multiple circuits. A single faulty circuit or an old-looking consumer unit alone doesn't necessarily mean a full rewire is needed.
Can you rewire my house while I'm living in it?
Yes, this is common — we phase the work room by room or floor by floor and agree temporary power arrangements for areas out of action during their phase. The practical plan depends on the layout and how the household uses the space.
Will you make good the walls and redecorate after chasing cables?
No — we chase cable routes and fill them to a plasterable finish, but plastering, painting and final redecoration are outside our scope. We agree cable routes and outlet positions with you in advance so a decorator can plan around them afterwards.
What's the difference between a full rewire and a partial rewire?
A full rewire replaces the entire fixed electrical installation. A partial rewire addresses specific circuits, rooms or floors where the rest of the installation is genuinely sound, based on what a survey or inspection finds.
Does a rewire include a new consumer unit?
Typically yes, since a rewire is the natural point to bring the consumer unit up to current standards alongside the circuits it serves, though the two are technically separate pieces of work.
Can a rewire be combined with an extension or renovation project?
Yes, and it's often the most sensible time to do it. First-fix wiring is completed before plastering and sequenced with the wider building programme, with new circuits checked against the existing board's spare capacity.
How disruptive is a rewire in an occupied home?
It depends on the extent of the work and how it's phased. We plan access, temporary power and the order of rooms at survey stage so you know in advance what to expect from each phase.
