Common Heating & Plumbing Questions Answered

A combination (or combi) boiler is the most popular choice across West London homes. Its compact design takes up minimal space whilst supplying hot water directly to your taps and radiators without needing a storage tank. Combi boilers heat water on demand, so you only pay for what you use. They're ideal for flats and smaller homes where space is at a premium, offering energy-efficient performance and straightforward installation.

A conventional boiler (also called regular or heat-only boiler) is typically found in older properties, though it can still suit modern homes with high hot water demand. These systems heat your home through a separate hot water cylinder, usually located in the loft or airing cupboard. They're an excellent option for areas with low mains water pressure or larger properties requiring simultaneous hot water to multiple outlets.

A system boiler draws water directly from the mains and stores heated water in a cylinder. This means multiple taps can run simultaneously without pressure drop – perfect for homes with more than one bathroom or busy family households. Whilst more compact than conventional systems, they require more space than combis and need proper insulation to maintain water temperature efficiently.

The correct boiler size depends on your property's number of radiators, bathrooms, and overall hot water usage. Boiler output is measured in kilowatts (kW) – generally, higher kW means more power. Most domestic boilers range from 24kW to 42kW.

A typical two-bedroom flat in Acton might need 24–28kW, whilst a four-bedroom house in Ealing with multiple bathrooms could require 35–42kW. Our engineers conduct heat loss calculations during surveys to ensure your new boiler is perfectly sized for your property – not undersized (leaving you cold) or oversized (wasting money).

Annual boiler servicing prevents the problems that develop when boilers sit idle during summer months. Without regular operation, components can seize, seals can dry out, and pressure can drop through microscopic leaks. When you try switching on heating in September, you're met with error codes or complete failure.

Regular servicing identifies developing issues before they cause breakdowns, maintains efficiency (reducing your gas bills), ensures safety compliance, and extends your boiler's lifespan. For landlords, annual servicing is legally required. For homeowners, it's the difference between reliable winter heating and expensive emergency repairs when temperatures drop.

We recommend servicing between May and August when our schedules allow thorough, unhurried work – and any required repairs won't leave you without heating during cold weather.

Kettling – that rumbling, boiling kettle noise from your boiler – is most commonly caused by limescale buildup on the heat exchanger. West London's moderately hard water deposits minerals over time, restricting water flow. This causes localised overheating where water boils, creating steam bubbles that collapse violently, producing the characteristic sound.

Kettling can also result from sludge accumulation or low water flow through the system.

Solutions include power flushing to remove sludge, chemical descaling for limescale, adding system inhibitor, or in severe cases, heat exchanger replacement. The appropriate fix depends on the underlying cause, which our engineers diagnose during inspection. Don't ignore kettling – it reduces efficiency, increases gas bills, and can damage your boiler permanently if left untreated.

Gas leaks are extremely dangerous and require immediate action. If you smell gas (a distinctive sulphurous odour like rotten eggs) anywhere in or around your property, follow these steps immediately:

1. Don't use electrical switches, mobile phones, or create any sparks
2. Open windows and doors to ventilate
3. Turn off the gas supply at your meter if you can access it safely
4. Evacuate the property and call us immediately from outside
5. Don't re-enter until a Gas Safe engineer confirms safety

When you call, we'll provide specific safety instructions for your situation and arrange emergency attendance. Gas leaks create severe fire and explosion risks, plus carbon monoxide poisoning dangers. Never delay investigating suspected gas leaks – your safety depends on immediate professional intervention.

Low hot water pressure affects many West London homes and stems from various causes:

• Incorrect system type: Combi boilers rely on mains pressure. If your area has poor mains pressure, a system or conventional boiler might suit better.
• Sediment buildup: Rust and limescale accumulate in tanks, cylinders, and pipes, restricting water flow over time.
• Distance from source: Long pipe runs between your hot water cylinder and outlets naturally reduce pressure.
• Faulty components: Partially closed valves, failed pumps, or blocked shower heads can all restrict flow.

Our engineers diagnose the specific cause affecting your property and recommend appropriate solutions – from power flushing and component replacement to system upgrades. Many Chiswick homeowners we've worked with discovered that upgrading to system boilers with unvented cylinders transformed their shower pressure completely.

Switch your heating on for 15 minutes once monthly throughout summer. This prevents pumps seizing, valves sticking, and seals drying out. Set a phone reminder – this simple habit prevents the majority of September startup failures we attend.

Turn all TRVs to maximum when heating switches off for summer. This prevents internal pins sticking whilst valves remain closed for months.

Summer is optimal for boiler servicing. It's less disruptive, any required work won't leave you without heating, and you'll enter winter confident your system is ready. Our schedules allow thorough work during summer that's impossible during winter's emergency-packed days.

Late August, check your boiler pressure (should read 1.0–1.5 bars when cold). Top up if needed so you're ready when heating season begins.

Cold radiators typically indicate one of several problems:

Air trapped in the system: If radiators are cold at the top but warm at the bottom, bleed them to release trapped air. This is the most common cause and takes minutes to resolve.

Sludge accumulation: Radiators cold at the bottom but warm at the top suggest sludge blocking water flow. This requires professional power flushing to remove years of rust and debris buildup.

Closed or faulty valves: Check both thermostatic and lockshield valves are open. Seized valves prevent water circulation even when fully "open."

System balancing issues: Some radiators heating whilst others stay cold suggests the system needs balancing – adjusting lockshield valves to distribute hot water evenly.

If bleeding doesn't resolve the problem, or multiple radiators are affected, professional diagnosis identifies the underlying cause and appropriate solution.

Bleed radiators when the top section feels significantly colder than the bottom, or when entire radiators stay cold despite the heating running. This occurs because trapped air displaces hot water.

1. Switch off your central heating and wait for radiators to cool
2. Start downstairs with the radiator furthest from your boiler
3. Work systematically towards the boiler, bleeding each radiator
4. Move upstairs and repeat – furthest radiator first, working towards the boiler
5. Check boiler pressure after bleeding and top up if needed

Use a radiator key, have cloths and a container ready, and only open the bleed valve until water flows steadily – no need to remove it completely. If you're bleeding radiators monthly, you have a leak allowing air into the system that needs professional investigation.

Unvented cylinders deliver mains-pressure hot water throughout your property without requiring pumps. The benefits include:

Superior water pressure: Powerful showers without noisy pumps – hot water arrives at mains pressure, not gravity-fed trickle.

Multiple simultaneous outlets: Run two showers, fill a bath, and use kitchen taps simultaneously without pressure drop. Ideal for busy family homes in Ealing where multiple bathrooms operate concurrently.

Space efficiency: No cold water tank in the loft means more usable space and simpler installation.

Energy efficiency: Better insulation than traditional cylinders reduces heat loss and energy waste.

Balanced hot and cold pressure: Both supplies run at similar pressure, making thermostatic shower controls more effective.

Unvented systems require annual servicing by qualified engineers (which we provide) and suit properties with good mains pressure. They're particularly popular in larger West London homes where conventional systems struggle with demand.

We hope we never experience another lockdown, but heating engineers are classified as essential services and were permitted to work throughout all previous restrictions.

If future lockdowns occur, Gasworks London is authorised to provide emergency repairs, servicing, and installations in your home. Gas Safe registered engineers working on heating systems are essential for public health and safety – particularly during winter when heating failures pose serious risks.

We follow all current safety guidelines including PPE, social distancing where possible, and hygiene protocols. If guidance changes, we'll update our website and inform customers immediately. Your heating and hot water are essential services we're committed to maintaining regardless of restrictions.

Many West London properties have stopcocks in awkward locations – under kitchen sinks behind pipework, buried in cupboards, or stiff from years without use. This becomes problematic during plumbing emergencies when you need to isolate water supply immediately.

A Sure Stop is a remotely operated stopcock installed in an easily accessible location with a simple switch rather than a difficult-to-turn valve. Benefits include:

• Instant water isolation during emergencies – no crawling under sinks
• Easy operation for elderly residents or those with limited mobility
• Battery-powered so it works during power cuts
• Professional installation ensures building regulation compliance

Installation typically takes 1–2 hours. Many of our Acton and Chiswick customers with period properties have found Sure Stops invaluable for properties where original stopcocks are virtually inaccessible or seized from age.

We can assess your property and recommend whether a Sure Stop suits your situation during any service visit or installation.