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Installations & upgrades

Electric heating installation and repairs

Electric heating relies on three things working together: the heater, the controls that switch it and the circuit that feeds it. We install, replace and repair storage heaters, panel heaters, heated towel rails and their thermostats and timers, and we connect and test electric underfloor heating. Before anything new goes in, we check that your installation can carry the extra load safely.

Request a quote 020 3883 1321
Checked first
Whether the circuit and consumer unit can take the new load
Underfloor heating
The mat is tested before, during and after the floor is laid
Paperwork
A certificate whenever a circuit is added or altered

  1. Laid on the prepared subfloor under the mat, it reduces the heat lost downwards, so the floor warms up faster.

  2. With the mat laid out, its resistance and insulation resistance are measured at the cold tail and compared with the manufacturer’s figures.

  3. The mat is checked again as the adhesive or levelling compound goes down, so damage from a trowel or a dropped tool is found before the floor is finished.

  4. A final set of readings on the finished floor, compared with the earlier ones and recorded with the certificate.

  5. The sensor sits midway between two heating runs, inside a conduit, so that it can be replaced without lifting tiles.

  6. The cold tail and the sensor conduit run straight up the wall to the thermostat, which is fed from a circuit with 30 mA RCD protection.

Fig. 1 — Section through an electric underfloor heating build-up, stepped to show each stage, with the wall thermostat (Illustration)

Sound familiar?

Common reasons for heating work

Underfloor heating needs the most planning, because once the mat is under tiles a damaged cable means lifting the floor. So the electrical work is fitted around the floor build-up, and the mat is checked at each stage rather than only at the end.

A heater gets hot in normal use, but its plug, flex, switch or socket should not. If any of those is scorched, discoloured or hot, or you can smell burning, stop using the heater: switch it off at the switch or socket beside it only if you can do so without touching anything damaged, then call us. If there is smoke or flame, get everyone out and call 999. Urgent electrical problems.

  • Storage heaters that are cold by the evening, or no longer seem to charge overnight
  • A heater, thermostat or timer that has stopped working
  • A heater whose circuit trips when it switches on
  • Old storage or panel heaters to replace, perhaps between tenancies
  • Underfloor heating or a heated towel rail as part of a bathroom or kitchen refit
  • Underfloor heating that no longer warms up, or a thermostat showing a floor sensor fault
  • Heating that runs when nobody needs it, because the controls are basic or no longer work
  • A move away from gas or oil, and the question of whether the supply can take it

Who this helps

  • Homes without mains gas

    Flats and houses heated by storage or panel heaters, where the heaters, their controls or the off-peak circuits are old or failing.

  • Bathroom and kitchen refits

    Electric underfloor heating and heated towel rails, timed with your tiler or fitter so the electrical work is ready before the floor goes down.

  • Rooms the main heating misses

    An extension, loft room or conservatory that the existing heating does not reach.

  • Landlords and managing agents

    Replacing failed or worn-out heaters, often between tenancies while the property is empty.

  • Small offices and shops

    Panel heaters and their controls, and repairs to heating that has stopped working.

The stages

Underfloor heating, stage by stage

When your tiler or floor fitter lays the mat, the electrical work has to fit around the floor. These are the points where it does.

  1. Assess the circuit and controls

    Ideally before the mat is ordered, we check the circuit can carry its load, how it will be protected and where the thermostat will go.

  2. First fix

    The supply cable, the thermostat back box and a conduit for the floor sensor go in before the walls and floor are finished.

  3. Test before covering

    Once the mat is laid out, it is tested against the values in its instructions, and we check that the sensor sits between two heating runs.

  4. Test during and after tiling

    The readings are repeated while the floor is covered and again when it is finished, so any damage is found before the heating is used.

  5. Commission and certify

    The thermostat is connected and set up, the circuit and its RCD are tested, and you receive the certificate. The floor stays off until it has cured.

Step by step

How the work is done

Before we quote

For a like-for-like replacement, photos of the old heater, its rating plate if you can see it without moving the heater or taking a panel off, the switch beside it and your consumer unit with its cover on may be enough for us to quote without a visit.

New heating, underfloor heating and whole-home changes normally need a visit. We look at the consumer unit, what the supply already feeds, where any new cable would run and where the thermostat or controls will go.

For underfloor heating, we also need to know who is laying the floor and when, so the first fix and the tests can be booked to match their dates.

  1. Check the supply and the load

    We confirm whether the heating can share an existing circuit or needs its own, whether the consumer unit has space and suitable RCD protection, and whether the supply can take the total load.

  2. Agree positions and controls

    Positions for heaters, thermostats and switches are agreed with you, within the manufacturer’s clearances and, in a bathroom, the zones around the bath or shower.

  3. First fix

    Where walls or floors are being refitted, new cables and back boxes for heaters, towel rails and thermostats go in before they are finished, run vertically or horizontally in line with the accessory they serve so they are easier to avoid later.

  4. Test the mat as the floor goes down

    For underfloor heating, the mat is tested at each stage of the floor, and each set of readings is compared with the last.

  5. Fit, connect and test

    Heaters, towel rails and controls are fitted and connected, and the circuit is tested, including the operation of any RCD that protects it.

  6. Set up and certify

    Thermostats, timers or storage heater controls are set up. Where the work adds or alters a circuit, you receive the certificate with its test results.

Scope

What is included

Included

  • A check that the circuit and consumer unit can supply the heating safely
  • Fitting heaters, towel rails, thermostats and timers in the positions agreed with you
  • Connecting electric underfloor heating, and testing the mat at each stage of the floor
  • Testing the circuit, including any RCD that protects it
  • Setting up the controls
  • An Electrical Installation Certificate for a new circuit, or a Minor Works Certificate for an alteration to an existing one

Depends on what we find

  • Whether the heating can go on an existing circuit or needs a new circuit from the consumer unit
  • Whether the consumer unit has a spare way and suitable RCD protection, or needs work first
  • For storage heaters, whether the off-peak supply is working, and whether the new model also needs an unrestricted supply
  • If a whole home is moving to electric heating, whether the incoming supply can take the total load; if it cannot, an increase has to be requested from your network operator
  • Whether old heaters can simply be taken out: some older storage heaters contain asbestos and have to be checked before they are moved

Afterwards

  • Leave new underfloor heating off until the adhesive, levelling compound and grout have cured for the times their manufacturers give
  • Keep the certificate, the mat’s test readings, any photos of the mat layout and the manufacturer’s instructions together: a mat warranty may depend on the readings
  • Do not drill or screw into a heated floor, and check the mat instructions before laying a thick rug or furniture without legs over it
  • Keep panel and storage heaters clear of furniture and curtains, and do not dry clothes on them; their instructions give the clearances

Not covered by this service: Gas boilers and other gas appliances (work on them must be done by a Gas Safe registered engineer), and heat pump installation; Insulation boards, levelling compound, adhesive and tiles, which are your tiler’s or floor fitter’s work; Tracing a fault elsewhere in the installation, which is our fault finding service.

The paperwork you may receive

  • Electrical Installation Certificate

    New installations, rewires and new circuits.

    • What was installed and the design details
    • A schedule of test results for each circuit
    • Signatures for design, installation and inspection

  • Minor Electrical Installation Works Certificate

    Small additions and alterations that do not add a new circuit, such as an extra socket on an existing circuit.

    • A description of the work
    • Test results for the circuit that was altered
    • The signature of the person responsible

Simplified outline, not a real certificate (Illustration)

Standards and regulations

We are a NICEIC Approved Contractor, registration number 619998000, and fully insured. How to check our registration and insurance.

  • REFHeating circuits installed and tested to the current edition of BS 7671, the IET Wiring Regulations
  • REFBS 7671 Section 753, which covers heating cables and embedded heating systems such as electric underfloor heating, and requires additional protection for their circuits by an RCD of not more than 30 mA
  • REFBS 7671 Section 701, which covers rooms containing a bath or shower and limits what can be installed in the zones around them
  • REFIn England, some electrical work in homes is notifiable under Part P of the Building Regulations and must be notified to building control, including a new circuit and an addition or alteration to a circuit in the space around a bath or shower

Questions

Questions about electric heating

Can you connect underfloor heating my tiler is laying?

Yes. Talk to us before the floor goes down, not after. The supply, the thermostat position and the sensor conduit need to be in place first, and the mat should be tested at each stage of the floor. Send us your tiler’s dates so the visits can be booked to match.

Can you replace my old storage heaters?

Usually, yes. We check the off-peak circuits and how the charging is switched first, because a newer model may need a different supply from the old one, such as an extra unrestricted supply for its controls. Some older storage heaters contain asbestos. If yours are very old, tell us and do not open the casing: they may need checking by an asbestos specialist before anyone moves them.

My storage heaters are cold in the morning. What could be wrong?

First check that the input or charge setting has not been turned down and that the switch beside each heater is on. If they still do not warm up overnight, the cause could be the heaters, their circuits or the off-peak switching that turns the charge on. Part of that switching can be in or beside the meter, which belongs to your energy supplier, and a fault there is for them to put right. If the problem started after your meter was changed, contact your supplier first.

My underfloor heating has stopped working. Can it be repaired?

The first things to check are the ones that do not involve the floor: the thermostat, the floor sensor and the supply to them, which can usually be repaired or replaced. If the tests point to the heating cable itself, the damaged point has to be located and the floor over it opened up, which may need a specialist. If its circuit trips again after one reset, leave it off and tell us.

Can I have an electric heater or towel rail in my bathroom?

Yes, if the product is made for it and its position suits the zones around the bath or shower. The zones decide what can be fitted where and how water-resistant it must be, and circuits in a bathroom need RCD protection. Tell us the product and where you would like it, and we will confirm whether that position works.

Is electric heating expensive to run?

It depends on the type of heater, your tariff, how well the room keeps its heat and how the heating is controlled. A thermostat and timer set to how you actually use the room help to stop it heating an empty space. We can talk you through the control options; questions about tariffs are for your energy supplier.

Can I buy the heaters or the underfloor heating mat myself?

You can. Before you buy, send us the make, model and wattage, so we can check that the circuit can supply it and that it suits where it is going. Keep the installation instructions: they set the clearances and the test values the installation has to meet.

When can I switch on new underfloor heating?

Not until the adhesive, levelling compound and grout have cured for the times their manufacturers give; your tiler can tell you when that is. Heating the floor too early can crack the adhesive or the tiles. When you first use it, follow the mat and thermostat instructions, which may ask you to raise the temperature gradually.

Often needed alongside

Next step

Tell us about your heating

If underfloor heating is part of a refit, get in touch before the floor is laid, so the first fix and the tests can be planned around your tiler. For heaters, the model details and a few photos usually tell us what the job involves.

What to send us

  • What heating you have now, and what you would like to change
  • The make, model and wattage of any heater or mat you have chosen, or a link to its specification
  • Photos of the consumer unit with its cover on, and of the existing heater and the switch beside it
  • For underfloor heating: the floor area, the floor finish and when the floor is due to be laid
  • Whether you are on an off-peak tariff such as Economy 7
  • The postcode, and whether the property is occupied or let

An enquiry is not a booking: we contact you first, and you see a written quote before anything goes ahead.

We list towns in London and surrounding areas, Kent, Essex, East Sussex and West Sussex. Check your postcode.

Call or email us for a free quote

Tell us the postcode and a little about the job. We will contact you to discuss it, and you get a written quote before any work starts. Quotes are free. Some survey or diagnostic visits may be charged: ask when you book.

Call 020 3883 1321 Email us

Our email address: support@dualcurrent.co.uk

Helpful to include

  • The postcode of the property
  • What the job is, or what is going wrong
  • Photos, if you have them, taken without removing any covers
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