Plain-English fault guide

No hot water? What your cylinder is telling you.

A quick, honest guide to the faults we're called out for most: no hot water, a Megaflo that won't heat, that pipe dripping outside, weak pressure and leaks. Here's what each usually means, how urgent it is, and what to do next.

Find your symptom

The faults we're called out for most.

Unvented cylinders (Megaflo, Gledhill, OSO, Santon and similar) run at mains pressure and rely on safety controls, so the right approach is to find the cause, not just swap the obvious part. Find the closest match below.

Most common

No hot water at all

Usually a failed immersion heater, a thermostat fault, a tripped safety cut-out, or a programmer and wiring issue. These need testing in order before any parts are fitted.

Megaflo won't heat up

A Megaflo (Heatrae Sadia) with no hot water often comes down to a failed element, a tripped reset button on the thermostat, or a high-limit cut-out that has operated, and keeps operating, for a reason worth finding. Our Megaflo repairs cover exactly this.

Pipe dripping outside / tundish drip

That small pipe dripping outside is often the cylinder's safety discharge. Inside you'll usually see the matching drip at the tundish. It points to expansion, pressure or safety-valve faults, not just a loose fitting.

Weak or falling pressure

Poor hot water flow upstairs, or pressure that's dropped off over time, usually traces to a blocked inlet strainer or a failing pressure reducing valve at the cylinder's valve set.

Leaks & damp patches

Water around the base, staining on the airing-cupboard floor, or a weeping valve. Most leaks are connections, valves or expansion vessels rather than the cylinder itself, and we'll be honest if it isn't.

Banging, rumbling or smells

Knocking or rumbling as it heats often means scale on the element or in the cylinder. A faint smell or discoloured water can mean the immersion or anode needs attention. Worth checking before it becomes a no-hot-water call.

How urgent is it?

What needs a call today, and what can wait.

A rough guide so you know whether to ring now or book in. If in doubt, send a photo on WhatsApp and we'll tell you honestly.

Call todayUrgent

Active leaks & water you can't stop

A steady leak, water tracking onto floors or ceilings, or a discharge you can't stop. Turn off the mains stopcock if water is escaping, and call us, leaks go to the front of the queue.

Book soonDays

No hot water & running tundish

No hot water is a priority visit, especially with children or vulnerable people at home. A dripping tundish isn't usually an emergency, but it wastes heated water daily and won't fix itself.

Plan aheadRoutine

Weak pressure, noises & due-a-service

Gradual pressure loss, rumbling or a cylinder that's never been serviced. Not urgent, but booking it in early is cheaper than waiting for the part that's on its way out to fail completely.

What to do next

A two-minute photo usually beats a guess.

Before you book anyone, send a few photos on WhatsApp. It often tells us the make, the likely fault and which parts to bring, so the first visit is the fixing visit.

Unvented cylinders are pressurised and protected by safety devices, so they should only be worked on by an engineer holding the G3 unvented qualification. If a fault has already been "fixed" once and come back, that's exactly the kind of job we sort. See how our repairs work.

The cylinder data label

Tells us the make, model and age, and which parts fit, Megaflo, Gledhill, OSO and the rest.

The tundish & discharge pipe

A photo of any drip helps us judge urgency and the likely cause honestly.

The valve set at the top

The pipework and expansion vessel around the cylinder tell the real story.

Any leak or staining

Plus a wider shot of the cupboard so we can see access.

Recognise your fault? Let's get it sorted.

Call for urgent faults, or WhatsApp photos of the cylinder, tundish and pipework for an honest first diagnosis, often before we've even been out.

Get in touch

Tell us what the cylinder is doing.

Covering Wetherby, Leeds, Harrogate, York, Tadcaster, Knaresborough and nearby villages.

Call 0113 418 0922

The fastest option for urgent faults and leaks.

WhatsApp 0113 232 9556

Send photos of the label, tundish and pipework for a fast first diagnosis.

No call-out fee. You only pay from when we arrive. Please note: diagnostic work is chargeable, and in the rare case we're unable to complete a repair, a diagnostic fee will still apply.

Get in touch

Tell us what's happening and we'll come back the same working day with honest advice and a clear price before any work starts.

How urgent is it?

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