The houses here, and why that changes the job

NW3 is large Victorian and Edwardian stock, and most of it never gave up its hot water cylinder.

• Two appliances, not oneA system or heat only boiler feeding a stored cylinder. Diagnosis has to establish which half is at fault before anybody quotes.
• Secondary circulationCommon in the larger houses. A failed pump on that loop looks exactly like a boiler fault from the tap.
• Zoned heatingUpstairs and downstairs on separate valves. One cold floor is usually a valve or a thermostat, not the appliance.
• Plant in awkward placesLoft, basement, converted cupboard. Access decides how long a job takes and it should be discussed before anyone is booked.

1. Tell us what it is doingAnd whether there is a cylinder in an airing cupboard, because that changes which half of the system we are looking at. A fault code on the display, if there is one, usually names the part.
2. The likely part, and a realistic slotWe tell you the likely part and a realistic slot. If we cannot reach you today we say so on the phone, rather than after you have waited in.
3. The engineer attends and runs a full diagnosticYou get a written breakdown before any repair begins: what has failed, what the parts and labour come to, whether the part is on the van or has to be ordered, and roughly how long the work will take. Nothing goes ahead until you have seen that and agreed to it. Parts are guaranteed for a year.

If it is not worth repairing, we will tell you on the phone rather than after we have charged you to attend. A fifteen year old boiler with a failed main heat exchanger is a replacement conversation, and pretending otherwise helps nobody.

Makes we repair most in NW3

Twenty years across every major make, and these are the ones we see here.

The most common system boiler in these houses, and the one most often paired with a stored cylinder.Worcester Bosch fault codes ecoTEC system and heat only models, frequently sitting on a uniSTOR cylinder.Vaillant fault codes Widely fitted in the flat conversions, and straightforward to get parts for.Baxi fault codes Common in the flats and in the smaller Belsize Park properties.Ideal fault codes Often found on older installations here that have been properly maintained.Glow-worm fault codes Still running in plenty of houses on the hill, and usually worth repairing.Potterton fault codes

Whatever is on the wall, photograph the badge before you call. The model number tells us more in five seconds than a description does in five minutes. The full list is on our boiler brands page.

Covering 26 districts across north London and south London of the river. Tell us your postcode and we will say plainly whether we cover it.

Next door to here we also cover Highgate, Muswell Hill and Crouch End, Hampstead Garden Suburb and Finchley and Islington and Highbury, all on the same kind of stock.