Frequently Asked Questions

Doherty's Gas serves North London and surrounding areas within approximately 10 miles of our Islington base (N1). Our service area includes Islington, Hackney, Camden, Stoke Newington, Finsbury Park, Highbury, Dalston, Shoreditch, Clerkenwell, Kings Cross, Kentish Town, Archway and many more. Contact us to confirm cover for your specific address.

Call us on 07817 148783 or use our online contact form. We'll confirm availability and arrange a convenient time to visit your property.

We cover boiler repair, boiler installation and replacement, annual boiler servicing, gas safety checks and CP12 certificates, central heating installation and repair, landlord gas safety certificates, gas leak detection, and emergency call-outs. Contact us if you're not sure whether your job falls within our scope.

We provide free, no-obligation quotes for installation and planned works. For boiler repairs, we can often give guidance on likely costs when you describe the fault. We'll always be upfront about costs before carrying out any work.

If your boiler is getting older, breaking down repeatedly or noticeably less efficient than it used to be, replacement is often more cost-effective than ongoing repair. We will give you honest, no-pressure advice on the best option for your specific situation.

Yes. We carry out gas safety inspections and issue the gas safety certificate (CP12) on satisfactory completion of the check. We work with both homeowners wanting peace of mind and landlords who require the certificate to meet their legal obligations.

Yes, landlord gas safety checks are one of our core services. We inspect all gas appliances in your rental property, check flues and ventilation, and issue the certificate on completion. We aim to work around your tenants where possible to minimise disruption.

If you smell gas, you should: open windows and doors for ventilation, avoid using any electrical switches, extinguish any naked flames, leave the property and call the National Gas Emergency Service on 0800 111 999 immediately. Do not re-enter until the emergency service has confirmed it is safe to do so.

Cold radiators are most commonly caused by air trapped in the system (bleeding is needed), a blocked or faulty thermostatic radiator valve, or a circulation problem caused by sludge build-up. We diagnose the exact cause before recommending a fix, rather than applying a blanket solution.

Power flushing is a cleaning process that uses specialist equipment to push water and descaling chemicals through your central heating system at high velocity, removing sludge, rust and scale. Signs your system may benefit from a power flush include cold spots on radiators, discoloured water when bleeding radiators, and the boiler cutting out regularly. We recommend a power flush whenever a new boiler is being fitted to an existing older system.