Gas Safe registered
Ravenheat specialists
CSI, CS, WH and the HE range. Twenty years on Ravenheat boilers, rates agreed beforehand, parts guaranteed a year.
Answered 24 hours a day by a technical customer service member.
Note which side the E is on. 08, E08 and 08E are one fault on three ranges.
No heating or hot water right now? Call 0203 868 6134. We will tell you the earliest realistic slot rather than the one you want to hear.
Add the code and your postcode and we can usually name the part before we attend.
Three steps, and you will know where you stand before anyone is booked.
On a Ravenheat the E moves, and that is why your search finds the wrong boiler. Low pressure is 08 on a CSI 120, E08 on a CS or WH, 08E on an HE. One fault, three labels, most guides cover one. Read us the code as it appears and we can name your range before you find the label. We are the London firm that tells you whether it is the boiler or the cylinder before anyone attends.
Three ranges, three formats, one set of faults. A bare number such as 01 or 08 is a CSI 120. An E in front is a CS or WH. An E after is the HE range. An HE owner searching E08 lands on advice for a CS, a different boiler with different parts, so the format is what stops the wrong component being ordered. An F range covers sensors across several models.
Shown as 01, E01 or 01E. It tried to light and failed, so there is no heating or hot water. Check the gas by trying a hob, and in winter thaw the condensate pipe. Five things cause it and only testing separates them: the burner, the electrode, the ignition lead, the spark generator, or the gas supply. Anyone naming the part without testing is guessing.
Shown as 08, E08 or 08E, the one Ravenheat fault most householders can clear. Fill through the loop cold to around 1.5 bar, then reset. The window is narrow: these lock out below roughly 0.6 bar and above 3, so overfilling causes the opposite problem. Dropping again within days means a leak, and topping up repeatedly causes sludge. A healthy gauge with the code showing is the sensor, F73 or F74.
| Code | What it means | What it usually turns out to be |
|---|---|---|
| 02 / E02 / 02E | Pump or circulation | The pump, air, or a closed valve |
| 09 / E09 / 09E | Overheat thermostat has operated | Circulation, not the burner. Cool fully, reset once |
| 10E | System pressure too high | A filling loop left open, or overfilling |
| F73 / F74 / F83 | Pressure sensor, or not enough water | The sensor, when the gauge itself reads normal |
| F77 | Gas valve motor | Safety critical. Engineer rather than reset |
| F84 | Flow and return temperatures differ too much | Circulation, usually a pump or a blockage |
On several Ravenheat models there is no reset button. You reset at the mains on and off switch on the control panel, which is why people conclude theirs cannot be reset and call somebody out. Look for a red intermittent warning light too: it means a high temperature lockout on the overheat thermostat, whether or not a number is displayed.
Two account for most calls.
Hot water never properly hot, heating faultless. The plate heat exchanger is scaling. The heating circuit is sealed so it scales once and stops; the hot water side takes fresh mains water at every tap. A diverter fault gives none at all, and an annual service catches it early.
Told parts are impossible to get? Ravenheat is British, independent since 1987 and building in Leeds, so the parts route is a Yorkshire factory rather than an importer. Ask which part and which supplier was checked before accepting a long lead time.
The E moves, and it names your boiler
A bare number is a CSI. An E in front is a CS or WH. An E after is an HE. Read us the code exactly as it appears and we can place your range before you find the label.
The code format tells you the range. The label confirms it.
CSI models show bare numbers, CS and WH put the E in front, the HE range puts it after. Older RSF models turn up in properties untouched this century. Read us the serial when you ring; it matches your appliance to the right parts. We work on every make of boiler.
The big difference between here and Leeds.
Water here carries roughly 277 milligrams of calcium carbonate per litre, from chalk the Thames and the Lea run through, so the plate heat exchanger scales faster than the manual allows. The same in Ealing and Northfields as Crystal Palace.
Scale drops out of solution faster the hotter the water gets. A combi set to deliver taps at 65 degrees furs up its plate heat exchanger faster than one set to 50, which is still hot enough to scald, and turning that dial down costs nothing. It applies to the tap setting, not a cylinder, which must reach 60 degrees.
Age does not decide it. The failed part does, and we would rather keep a boiler running.
| What has failed | Under 8 years | 8 to 14 years | 15 years and older |
|---|---|---|---|
| Pressure and temperature sensors | Repair | Repair | Repair if parts exist |
| Electrode, ignition lead, spark generator | Repair | Repair | Repair |
| Expansion vessel, pump | Repair | Repair | Repair |
| Fan, thermal fuse | Repair | Repair | Depends on the rest of the boiler |
| Diverter valve, plate heat exchanger | Repair | Repair | Repair if the part is still made |
| Gas valve | Repair | Borderline, we will be straight with you | Replace |
| Control board | Check the guarantee first | Usually replace | Replace |
| Main heat exchanger | Guarantee claim if registered | Replace | Replace |
Under eight years old it is a repair without argument. The honest point between eight and fourteen: a board or heat exchanger costs about what it does on a premium boiler while the appliance is worth less, so replacement wins earlier here. Cheap repairs stay worth doing as long as they do anywhere. See boiler replacement and our cost guide.
Most firms here are combi-only, which does not suit a city of large houses.
A Ravenheat WH System or regular model runs a stored cylinder with its own thermostat, immersion element and, if unvented, its own safety devices. When the hot water goes the boiler takes the blame and is usually fine: a cylinder sensor out of its pocket, a failed motorised valve, or a scaled immersion element.
Water at its tundish means a safety device has failed, and is never something to cap. That needs G3 as well as Gas Safe registration; we hold both, so unvented cylinder repair happens on the same visit, and larger houses across Putney and Barnes usually get a scale reducer with it.
Boiler problem? We're here 24/7
Emergency boiler repairs across London, north and south of the river
Call 0203 868 6134London, north and south of the river.
These are where we work most, not a boundary. An engineer attends anywhere in north London and south London. Tell us where you are and we will say plainly when we can get to you.
If you smell gas: do not touch any switches. Open the windows, leave the property, then call the National Gas Emergency Service on 0800 111 999. That line is free and open 24 hours. Call them before you call us.
If a carbon monoxide alarm is sounding: get everyone out immediately, then call 999 if anyone feels unwell. Do not go back in until the property has been ventilated and checked.
If the boiler locks out repeatedly: try one reset. If it locks out again straight away, stop. Repeated resets hide a fault that is still there, and on a gas appliance that is not a risk worth taking.
Under the Gas Safety (Installation and Use) Regulations 1998, only a Gas Safe registered engineer may work on gas appliances. Never open the boiler casing yourself.
Because the E moves. Ravenheat use three formats and most guides cover one. A bare number such as 08 is a CSI 120, an E in front is a CS or WH, an E after is the HE range. All three are the same fault, so an HE owner searching for E08 lands on advice for a different boiler with different parts. We work on every make of boiler.
Ignition failure, shown as 01, E01 or 01E by range. The boiler tried to light and could not, so there is no heating or hot water. Check the gas by trying a hob, and in cold weather thaw the condensate pipe. Five things cause it and only testing separates them: the burner, the electrode, the ignition lead, the spark generator, or the gas supply. No heat at all? See emergency boiler repair.
Around 1.5 bar cold. The window is narrower than people expect: these boilers lock out below roughly 0.6 bar and above 3, so overfilling causes the opposite problem. Code 08, E08 or 08E means too little. A healthy gauge with the code showing means the sensor has failed, F73 or F74. Repeated topping up means a leak and causes sludge.
On several models there is not one. You reset at the mains on and off switch on the control panel, which is why people conclude theirs cannot be reset. Check for a red intermittent warning light too, because on these models it means a high temperature lockout on the overheat thermostat. Reset once only. Worn ignition parts are what an annual service catches first.
Less than a budget badge suggests. Ravenheat is British, independent since 1987 and building in Leeds, so the parts route is a Yorkshire factory rather than an importer. If quoted a long lead time, ask which part and which supplier was checked, because a genuine availability problem names both. Real scarcity applies mainly to the oldest RSF models. See our cost guide.
Yes, and it is a large part of what we do. A WH System or regular model runs a stored cylinder with its own thermostat, immersion element and, if unvented, its own safety devices. Unvented work needs G3 as well as Gas Safe registration and we hold both, so the cylinder is diagnosed on the same visit. A failed cylinder sensor shows no boiler code. See unvented cylinder repair.
Few other makes let a letter position identify which boiler you own.
No gas supply? Plenty of London flats run without one, so we also cover electric boiler repair.
Read us the code exactly as it appears, E and all, plus the model. With those two we can usually name the part before anyone is on the way.
Gas Safe registered. Unvented cylinder qualified. Parts guaranteed for a year. Covering London, north and south of the river, 24 hours a day.
