Croydon & the CR postcodes
Boiler servicing in Croydon and the CR postcodes
An annual boiler service is £90, it takes us around an hour, and it is a fixed price whether the boiler passes cleanly or turns out to need work. What you get for it is a service to the manufacturer’s own schedule: the case comes off, the combustion is measured with an analyser rather than judged by eye, and the Benchmark record in the front of your boiler manual is filled in and dated. That last part is the one that matters if you ever have to make a warranty claim.
What you get
What the job includes
- A combustion test with a calibrated flue gas analyser. The probe goes in the flue sampling point and we record the CO and CO₂ readings and the ratio between them. A boiler burning correctly gives a ratio well under 0.004; a rising number means the burner is starving of air or the heat exchanger is fouled, and it shows up here long before anyone smells or hears anything.
- The gas rate checked at the meter against the figure on the boiler’s data plate. Timed over two minutes with everything else in the house turned off, this tells us whether the appliance is actually getting the gas it was designed to burn. Underrating is common on older combis and is usually a partly blocked injector or an undersized supply pipe.
- The burner, injector, main heat exchanger, condensate trap and combustion chamber cleaned where the manufacturer’s schedule calls for it. Some boilers require a strip and clean every year, others only when the combustion readings say so. We follow what the maker specifies for your model rather than a generic checklist.
- The expansion vessel pre-charge tested with the system side depressurised, and re-gassed if it has gone flat. A failed vessel is behind a large share of the "boiler keeps losing pressure" calls we get, and it is invisible unless someone puts a gauge on the schrader valve.
- Every safety device operated and confirmed working: the pressure relief valve, the overheat thermostat or thermal cut-out, the flame supervision device, and the pressure or flow switch. These are the components that stop a fault becoming a dangerous one, and they are the components that are never tested on a visual check.
- The flue inspected along its full accessible length, at the terminal outside, and at every joint. We check the seals, the fall back towards the boiler, the clearances to windows, doors, air bricks and boundaries, and whether the terminal is discharging where it should be rather than into a neighbour’s side return.
- The condensate pipe followed from the boiler to where it discharges. We check the fall, the diameter, the length of any external run and whether it is insulated. A condensate pipe that freezes locks the boiler out on the coldest night of the year, and it is the most preventable winter breakdown there is.
- System pressure checked and topped up, the filling loop confirmed as isolated afterwards, and the magnetic filter emptied and inspected if one is fitted. What comes out of that filter tells us more about the health of the system than the boiler ever will.
- Case seals, ventilation and the compartment itself checked. A room-sealed boiler depends on its case being gas-tight. Cupboard doors that have been replaced, shelves built round the appliance, or a boxed-in unit with no access all get flagged, because they affect both safe operation and whether the next engineer can work on it.
- The carbon monoxide alarm tested if there is one, and its position and expiry date checked. Alarms have a service life, usually seven or ten years, and a surprising number of the ones we test are past it.
- The Benchmark service record in your boiler manual completed, signed and dated, with our Gas Safe registration number on it. If the book has been lost we start a fresh service record and note the history we can establish.
- A written summary of the readings we took and anything we would want you to keep an eye on, with a price for any work we think it needs. Nothing gets done on the day beyond the service without you agreeing to it first.
Local knowledge
Croydon water, and the flues nobody can see
Two things about this borough change what a service finds here, and neither of them appears on a national company’s template page.
The first is the water. The CR postcodes are supplied largely from chalk boreholes under the North Downs, and chalk water is hard water: comfortably into the very hard band, well over 200 mg/l of calcium carbonate. Every time that water is heated past about sixty degrees it drops some of that calcium out as scale. In a combi it lands first on the plate heat exchanger that makes your hot water, which is why so many Croydon combis develop the hot-cold-hot pattern in the shower where the temperature swings while the flow stays the same. On the heating side it bakes onto the main heat exchanger and you hear it as kettling, a banging or rumbling as the boiler fires. We take that seriously at a service in a way an engineer working a soft-water area would not need to, because here it is not the exception. If the combustion figures and the flow temperature suggest scale is building, saying so at the ten year point is worth more than replacing a heat exchanger at the fifteen.
The second is where the boilers are. The dense Victorian and Edwardian terraces through Thornton Heath, Selhurst, South Norwood and Norbury have been converted into flats at a rate few London boroughs match, and central Croydon added a large stock of purpose-built and office-converted flats on top of that. In a converted or purpose-built flat the flue very often does not go straight out through the wall behind the boiler. It runs horizontally through a ceiling or riser void to reach an outside wall, sometimes across a hallway, sometimes past another flat. Since January 2013 a flue concealed in a void must have inspection hatches fitted so an engineer can actually see it. Where there are none, the appliance is classified At Risk and, with your permission, turned off. That is not us being difficult, it is a national rule, and it catches out more people in CR than almost anywhere because of how the housing stock here was carved up. We will tell you before we come whether your flat is likely to need hatches, so it is a conversation and not a nasty surprise on the doorstep.
How it goes
What happens, step by step
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Booking, and what we ask on the phone
We take the make and model off the front of the boiler, roughly how old it is, and where in the property it sits. If it is a flat we ask where the flue comes out, because that tells us whether inspection hatches are likely to be an issue before anyone wastes a morning. We also ask whether you still have the boiler manual with the Benchmark section in it. Have a rough look before we arrive; it is usually in a kitchen drawer or taped inside the boiler casing. Appointments run Monday to Saturday, seven in the morning to eight at night, and we give you a two hour arrival window rather than a day.
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The boiler is run before anything is opened
The first thing that happens is that we fire the boiler from cold and watch it work. How long it takes to light, whether it cycles, what the flow and return temperatures settle at, how the pump sounds, whether the hot water holds steady when a tap is opened. A boiler that has been running all morning has already hidden half its symptoms, so this is deliberately the first job rather than the last. We check the system pressure cold, look at the controls and the thermostat settings, and ask you what it has been doing lately, because the thing you have been putting up with for six months is often the most useful piece of information available.
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Combustion measured, not guessed
The analyser goes into the flue sampling point and the boiler is tested at both low and high fire where the manufacturer requires it. We record CO in parts per million, CO₂ as a percentage, the ratio between them, and the flue gas temperature. Then we rate the gas at the meter and compare it to the data plate. Between them these numbers tell us whether the appliance is burning cleanly and getting the gas it needs. This is the single clearest line between a real service and a look-and-wipe: a visual check cannot produce any of these figures, and without them nobody can honestly say the combustion is safe.
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Case off, and cleaned to the maker’s schedule
The case comes off and the seals are checked as it does. What happens next depends on the model. Some manufacturers require the burner and heat exchanger removed and cleaned annually; others specify a clean only when the combustion readings or a visual inspection call for it, and stripping those unnecessarily risks damaging seals that were fine. We work to the schedule for your specific boiler. The condensate trap is emptied and flushed on almost everything, because that is where the sludge collects and it is a common cause of lockouts. Electrodes are checked and reset to the correct gap, and the fan and air pressure switch are checked for the right operation.
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Flue, ventilation, safety devices and the system round it
The flue is inspected along whatever length is accessible, at every joint, and at the terminal outside, with the clearances measured to anything that matters. Ventilation and the compartment are checked. Then every safety device is operated in turn rather than assumed to work. After that we look outward from the boiler: expansion vessel pre-charge, magnetic filter, condensate run, radiator flow at a couple of points, and the CO alarm. That last group is where a service earns its money, because most of what shortens a boiler’s life is not in the boiler.
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The Benchmark record, and a plain summary
The Benchmark service record gets completed properly: date, readings, our Gas Safe registration number and a signature. If the book is missing we start a new record and note what history can be established. Then we go through what we found in ordinary language, including the things that are fine, because a service where nobody explains anything is indistinguishable from a service that never happened. Anything that needs attention is priced before you decide, and if it is not urgent we will say so rather than dress it up. You get the readings in writing so that next year there is something to compare against.
Before you ring
Questions we get asked
How much does a boiler service cost in Croydon?
Ours is £90, fixed. That covers the full service to the manufacturer’s schedule, the combustion analysis, and the Benchmark record being completed. It does not change if the boiler turns out to be dirty or awkward to get at. If we find a fault that needs a part, we price it and you decide; nothing is fitted without your agreement.
How long should a boiler service take?
Around an hour for a straightforward combi in an accessible spot, longer if the boiler needs a full strip and clean or is boxed into a cupboard. Be wary of anything much under half an hour. Running the appliance from cold, rating the gas at the meter and testing the combustion at high and low fire simply take the time they take, and a twenty minute visit has not done them.
How often does a boiler need servicing?
Once a year, and every boiler manufacturer’s warranty says the same. The twelve month clock runs from the last service, not from January, so if yours was done in March it is due next March. Autumn is the sensible time to book if you have a free choice, because a fault found in October is an inconvenience and the same fault found in January is a cold house and a queue.
What is the difference between a service and a gas safety certificate?
A gas safety check confirms an appliance is safe on the day: it is tight, it burns correctly, the flue works and the ventilation is adequate. That is what the CP12 records, and it is £75. A service goes further, because it includes cleaning to the manufacturer’s schedule and the maintenance that keeps the boiler working rather than just safe. A safety check on its own does not satisfy a warranty, and it is not a service.
I am a landlord. Does the CP12 cover me for the service as well?
No, and this catches a lot of landlords out. The Gas Safety (Installation and Use) Regulations require an annual safety check and a record given to your tenant within 28 days, which the CP12 does. The same regulations separately require appliances to be maintained in a safe condition in line with the manufacturer’s instructions, and manufacturers specify an annual service. We do both on one visit for CR properties and price them together when you book.
Will my warranty be void if I miss a service?
Very possibly. Manufacturers offering five, seven, ten or twelve year warranties make them conditional on an annual service being carried out by a Gas Safe registered engineer and recorded in the Benchmark book. When a claim comes in, the book is the first thing asked for. A missed year, or a year with no entry, is the usual reason a claim on an otherwise valid warranty is refused, and it is refused on paperwork rather than on the fault itself.
What is the Benchmark book, and what if I have lost it?
It is the installation and service record bound into the front of your boiler manual, run as an industry scheme, and it is where each annual service is signed and dated. If it has gone missing, we start a fresh service record and note what history can be established from invoices or previous engineers. That is not as good as an unbroken run of entries, but it is far better than nothing, and it starts the record again from the date we attend.
Can I service my boiler myself?
No. Working on a gas appliance without being on the Gas Safe Register is a criminal offence under the Gas Safety (Installation and Use) Regulations, not merely a bad idea. Beyond the law, a service needs a calibrated flue gas analyser and a gas rate taken at the meter, and neither can be done by eye or by hand. What you can usefully do yourself is keep the flue terminal clear outside, check the pressure gauge now and then, and bleed radiators.
Do you check the radiators during a boiler service?
We check flow at a couple of radiators and look for the cold-at-the-bottom pattern that means sludge, but a boiler service is not a heating system service and we would not claim otherwise. If the radiators are the actual problem, balancing or a powerflush is separate work with its own price, quoted after we have seen it. We will tell you which of the two you have got rather than selling you a flush you do not need.
My boiler is nearly twenty years old. Is it still worth servicing?
Yes, and arguably it matters more at that age. An older appliance is where combustion drifts, seals harden and heat exchangers fur up, and those are exactly the things a service measures. What we will also do is give you a straight view on whether it is nearing the end. A twenty year old boiler that tests cleanly and has available parts is worth keeping; one that is failing its combustion figures or has obsolete parts is worth planning to replace before it decides for you.
What happens if you find something wrong?
We tell you what it is, how serious it is, and what it costs to put right, then you decide. Most faults found at a service are not urgent and can be booked in. If we find something Immediately Dangerous or At Risk, we have to make it safe, which can mean turning the appliance off with your permission and issuing a warning notice. That is rare, and we would rather find it in October than have you find it in January.
Which areas do you cover for servicing?
Croydon and the CR postcodes, working from Thornton Heath. That takes in CR0, CR2, CR4, CR5, CR7 and CR8, plus the SE25 and SW16 edges of the borough. We are Gas Safe registered under number 919881, which you can check on the register yourself. Hours are Monday to Saturday, seven in the morning to eight at night, with emergency cover round the clock.
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