--- title: "Immersion Heater Replacement | R.K Plumbing, Woodingdean" description: "No hot water? R.K Plumbing & Heating replace faulty immersion heaters safely and tidily across Brighton, Hove, Lewes and Sussex. Call 01273 911551." canonical: "https://www.rkplumbingandheatingservices.com/services/immersion-heater-replacement" --- General Plumbing # Immersion Heater Replacement When the tank stops heating, or only ever gets as far as lukewarm, a worn out immersion element is usually behind it. We isolate the electrics, drain the cylinder, fit a new element and seal, and get the hot water working properly again. [Call 01273 911551](tel:+441273911551) ![Joule unvented hot water cylinder standing in a cupboard with tundish and pressure relief pipework](/_next/image?url=%2Fapi%2Fmedia%2Ffile%2Frk-cylinder-installation-20220407-04.jpg%3Fprefix%3Dtenants%252F6a73367026944505f092a67a%26v%3D1787045582073&w=1536&q=75&dpl=dpl_J3UkotoCWSfG7mH3JdDuNRVcD7J7)![Joule unvented hot water cylinder standing in a cupboard with tundish and pressure relief pipework](/_next/image?url=%2Fapi%2Fmedia%2Ffile%2Frk-cylinder-installation-20220407-04.jpg%3Fprefix%3Dtenants%252F6a73367026944505f092a67a%26v%3D1787045582073&w=1536&q=75&dpl=dpl_J3UkotoCWSfG7mH3JdDuNRVcD7J7) ## What's involved An immersion heater fault is part electrical and part plumbing, and these are the pieces of it we deal with. ### Element Replacement Removing the failed heater and fitting a new element of the correct length and rating, on a fresh gasket, without straining the cylinder boss. ### Cylinder Thermostat Replacement Renewing the thermostat where it is sticking, running cold or overheating, so the new element is not switched by a worn out control. ### Seized Element Removal Freeing elements that have corroded into the boss, working steadily with the right spanner rather than forcing and splitting the cylinder. ### Drain Down, Refill And Test Draining to below the boss, refilling, bleeding the air through and checking the joint holds before the power goes anywhere near it. ## Why the hot water has gone An immersion heater is a simple thing: an electric element screwed into the side or top of your hot water cylinder, switched by a thermostat. Simple does not mean immortal. Elements scale up, corrode and eventually burn out, and in a hard water area they do it sooner. The symptoms tend to be familiar. No hot water at all is usually a failed element or a tripped supply. Water that gets warm but never hot often points at the thermostat rather than the heater. A tank that heats at the top and stays cold lower down can mean a twin element cylinder where only one of the two is still working. Before we change anything, we test rather than assume, because fitting a new element into a fault that lives in the wiring or the thermostat solves nothing. > Most of the diagnosis is done before a spanner comes out of the bag. ## The order the job has to be done in This is electrics and plumbing in the same small space, so sequence matters more than speed. We isolate the supply at the switched spur and the consumer unit, then prove it dead with a tester rather than trusting a switch. The cold feed is turned off next, and the cylinder drained down to below the level of the boss, which on a top entry element means draining a good deal of it. The cover comes off and the wiring is noted before anything is disconnected. Then the old element comes out. This is the part that can be slow: an element that has sat in a cylinder for years is often seized, and it needs steady, correctly applied force with an immersion spanner. Rushing it distorts the boss or splits the cylinder, and then a straightforward job has turned into a new cylinder. With the old one out we clean the sealing face, fit the new element on a fresh gasket, and start the thread by hand so it cannot cross. It is tightened enough to seal and no further. The wiring goes back exactly as it came off, the earth included, and the cylinder is refilled with a hot tap open so the air can get out. More information ### What we check before we leave - The joint at the boss, watched under full pressure once the cylinder is full - That the cylinder is genuinely full, with air bled through and no airlock left in the pipework - Wiring connections remade tight, with the earth continuity intact - The thermostat calling for heat and switching off at the set temperature - The element drawing current and actually heating the water - The cylinder jacket or insulation put back properly, not left off - Any redundant or damaged switch or flex flagged to you One thing worth knowing: hot water does not come back the moment the power does. A full cylinder takes a few hours to reach temperature from cold, which is normal and not a sign the new element has failed. > If the thermostat is as tired as the element, changing one and leaving the other just brings us back. ## Where it fits with everything else An immersion fault is sometimes a symptom of a cylinder that is nearing the end of its life, and we will tell you if that is what we are looking at rather than keep replacing parts on it. We work on cylinders, boilers, central heating and general plumbing, so if it turns into a bigger conversation we can have that one too. We are based in Woodingdean and cover Brighton, Hove, Worthing, Lewes, Shoreham-by-Sea, Haywards Heath, Seaford, Burgess Hill and surrounding Sussex towns. ### Ready to talk? Tell us what the tank is doing and we will let you know what is most likely behind it. [Call 01273 911551](tel:+441273911551) ### While you're here - [Emergency Plumber](/services/emergency-plumber)→ - [Leak Detection](/services/leak-detection)→ - [Burst Pipe Repair](/services/burst-pipe-repair)→ ## Worth considering General Plumbing ### Hot Water Cylinder Installation Tidy, fully tested vented and unvented hot water cylinder installation for homes across Brighton, Hove and Sussex. [Hot Water Cylinder Installation→](/services/hot-water-cylinder-installation) General Plumbing ### Unvented Cylinder Installation Mains-pressure hot water cylinders supplied, fitted and commissioned by a Gas Safe registered team in Brighton, Hove and Sussex. [Unvented Cylinder Installation→](/services/unvented-cylinder-installation) General Plumbing ### Toilet Installation Toilets repaired and fitted level, sealed and leak-tested, from a simple swap to a wall-hung pan, for homes across Brighton, Hove and Sussex. [Toilet Installation→](/services/toilet-repair-installation) General Plumbing ### Tap Repair Tidy, reliable repairs for dripping, stiff or noisy taps across Brighton, Hove and surrounding Sussex towns. [Tap Repair→](/services/tap-repair-replacement) General Plumbing ### Low Water Pressure Diagnosis and repair of low water pressure at taps, showers and appliances, for homeowners across Brighton, Hove and Sussex. [Low Water Pressure→](/services/low-water-pressure) General Plumbing ### Pipework Repair Tidy, tested repairs for leaking, burst or corroded pipework, serving Brighton, Hove and nearby Sussex towns. [Pipework Repair→](/services/pipework-repair) ## Before you book The questions that come up most often when the hot water stops. How do I know it is the immersion heater and not something else? No hot water at all usually points to a failed element or a supply that has tripped, while water that warms up but never gets hot often means the thermostat. A cylinder that is hot at the top and cold lower down can mean a twin element unit with one heater out. We test the supply, the thermostat and the element before deciding, rather than changing parts and hoping. Can I change an immersion heater myself? It is not a job we would recommend taking on. It combines live electrics with a cylinder full of hot water, and old elements are frequently seized so hard that forcing them damages the cylinder itself. Getting it wrong turns an element replacement into a cylinder replacement. Will you need to drain the whole tank? We drain down to below the level of the element, which on a side entry heater means part of the cylinder and on a top entry one means most of it. The cold feed is isolated first, and we refill with a hot tap open so the air is pushed out as it fills. It adds time to the visit, which is worth knowing when you plan the day. How soon will I have hot water again? Once the new element is in, tested and switched on, a cylinder full of cold water still takes a few hours to come up to temperature. That is completely normal and is not a sign of a problem. We confirm the element is drawing current and heating before we leave. Should the thermostat be replaced at the same time? Often it makes sense. The thermostat and the element live in the same conditions and age at the same rate, so replacing a burnt out element while leaving a sticking thermostat tends to bring us back. We will tell you what we find and let you decide. My immersion heater keeps tripping the electrics. What does that mean? That is usually an element that has broken down internally and is leaking current to earth, and the trip is doing its job. Leave it switched off and give us a call rather than resetting it repeatedly. It is a fault to be fixed, not reset. How do I get a price for replacing an immersion heater? Ring us on 01273 911551 and describe what the hot water is doing and what sort of cylinder you have, if you know. That tells us a lot before we arrive. You are also welcome to call in and talk it through at 58 Warren Road in Woodingdean. Which areas do you cover? We are based in Woodingdean and cover Brighton, Hove, Worthing, Lewes, Shoreham-by-Sea, Haywards Heath, Seaford, Burgess Hill and surrounding Sussex towns. ## Let's get your hot water back Tell us what the cylinder is doing and we will come and put it right. [Call 01273 911551](tel:+441273911551)