Grant Boiler Repairs London

Grant Boiler Repair London

Specialist advice on Grant boilers – including the key first step in London: confirming whether you have an oil or gas system.

Jump to:
Quick Checks –
Oil vs Gas –
Common Problems –
Your Options –
Landlords

Quick Checks (60 Seconds)

Before you book an engineer, these basic checks often resolve “no heat” situations:

1. Check your fuse box: a tripped breaker can mimic a boiler failure.
2. Check thermostat and programmer: power cuts can reset schedules; wireless controls may need fresh batteries.
3. Check system pressure (sealed systems): if your gauge is below 1 bar, see our pressure guide before topping up.
4. Check the display for a fault code: note it down or photograph it before you call.
5. Reset once only: if it locks out again after a single reset, stop and book an engineer.

About Grant

Grant is an established manufacturer best known for oil-fired boilers and renewable heating products. They’re common in Ireland and rural parts of the UK, but uncommon in London where most homes use mains gas.

Oil vs Gas: Why This Matters in London

If you have a Grant unit in a London property, the first question is simple: is it oil or gas?

Oil boiler? You will typically have an oil tank on site. Oil work should be carried out by an OFTEC registered engineer.

Gas boiler? All gas work must be done by a Gas Safe registered engineer.

Because oil heating is rare inside London, many “Grant boiler” searches locally are:

• London properties that still have an older oil setup (or a previous commercial or mixed-use history)
• Edge-of-London properties where oil has been retained
• People who have a Grant-branded heating product and aren’t sure what it is

Common Grant Problems

Grant appliances can show the same “headline symptoms” as any heating system, but the underlying causes differ by fuel type.

• Ignition / lockouts: can be electrical, sensor-related, combustion-related, or fuel-supply related (oil systems have additional burner and fuel-line factors).
• No heating or no hot water: could be pump issues, controls, motorised valves, or system-side problems.
• Low pressure: often a leak, expansion vessel issue, or pressure relief valve discharge (sealed systems).
• Leaking: seals, pump glands, valves, or heat exchanger corrosion.
• Noisy system: kettling, banging, gurgling or whistling can indicate limescale, sludge, trapped air, or pump wear.
• Oil-specific issues: burner servicing needs, nozzle issues, fuel contamination, air in the line, and tank sludge (oil models only).

What We Check on Arrival

For Grant gas boilers, our Gas Safe engineer will typically:

• Confirm the exact model and whether it’s heating-only, system or combi setup
• Inspect for leaks, corrosion, scorching and any flue/ventilation concerns
• Check controls, system pressure (where relevant), and circulation basics
• Read fault codes and test safe operation where appropriate
• Assess realistic parts availability for your specific model
• Give a clear recommendation: repair viability vs replacement economics

For Grant oil boilers, you typically need an OFTEC engineer for oil burner work. If you’re unsure what you have, contact us and we’ll help you identify the system first.

Repair vs Replace: The Practical View

Where brands or fuel types are uncommon locally, the repair equation changes because parts and engineer availability matter just as much as the fault itself.

• Parts lead times: uncommon models can take longer to source parts than mainstream London boiler brands.
• Engineer availability: oil work requires OFTEC skills; in London that can mean fewer options and longer waits.
• Running costs: oil pricing fluctuates and can be higher than mains gas for many households.
• Long-term maintenance: mainstream systems tend to be simpler and cheaper to support locally.

Example repair costs (illustration only): a diagnosis and repair could be £400-600+ depending on the fault, parts availability, and access. If specialist parts or oil-burner work is required, costs can rise.

Compare that to switching: a new mainstream gas boiler from £1,899 gives you warranty-backed reliability, readily available parts, and straightforward future servicing.

Landlords: Consider the Long-Term Picture

If you’re managing a rental with a Grant boiler in London, think beyond today’s repair:

• Maintenance complexity: oil systems can be harder to support quickly in London.
• Tenant experience: no heat or no hot water creates complaints fast, especially if parts or specialist engineers are delayed.
• Predictable costs: planned upgrades are usually cheaper than repeated emergency call-outs.
• Compliance: ensure the right qualified engineer is servicing the system (Gas Safe for gas, OFTEC for oil).

We support landlords across London with Gas Safety Certificates (CP12) and practical heating upgrades. See our London landlord checklist.

Still Want to Keep Your Grant Running?

Understood. If it’s a Grant gas boiler, our Gas Safe engineers can diagnose and advise on repair feasibility. If it’s oil, we can help you identify the system and point you towards the right next step, including recommending an OFTEC engineer where needed.

Brands We Install

If you’re moving to a mainstream London-friendly setup, we install leading UK-supported brands:

London Wide Coverage

We cover all London boroughs for gas boiler installation and repairs. See our London coverage page for service areas.

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