Makes we repair
What does F2 mean?
F2 means one of two faults, depending on the make of boiler. On an Ideal, F2 is flame loss, the burner's flame going out while the boiler was running. On a Viessmann, F2 means the temperature limiter, the boiler's overheat cut-out, has tripped, and the burner has locked out.
An Ideal's F2 can come from something as simple as the gas being off, or a prepayment meter out of credit. A Viessmann's manual starts its checks with the water in the heating. Some of the causes are safe for you to check. The rest need an engineer.
Which boilers show F2?
F2 is a code of Ideal and of Viessmann, and it means a different fault on each, so the make comes first. Every boiler fault code, make by make.
F2 on an Ideal boiler
The code F2 shows on Ideal's Logic Combi ESP1, Logic Code Combi ESP1 and Exclusive2. An ESP1 may show Fn or Ln for the same fault. The Logic Combi from before the Combi2, and the Logic+ Heat from before the Heat2, show F2 as well.
On the Logic Combi2, System2 and Heat2, and the i-mini, the code is F 02, with two figures. The Logic+ Combi2, the Logic Max Combi2 and the Vogue Max show no code, and the screen reads Flame Loss instead. Ideal boiler repair, and every other Ideal code. L2 on an Ideal: the boiler tried to light and locked out.
F2 on a Viessmann boiler
The Vitodens 100-W of the types B1HC and B1KC show F2 when the temperature limiter, the overheat cut-out, has tripped. The 111-W B1LD, the 050-W BPJD and the 200-W B2HB use the same code. On a B1HC the fault symbol flashes and R appears, because the burner has locked out.
The newer One Base Vitodens, such as the 100-W B1HF and B1KF, number their faults. The same overheat shows in one of two ways:
- the code 62, when the high-limit cut-out has tripped
- the code 345, when the temperature limiter has tripped and the burner restarts by itself once the boiler has cooled
The type is on the boiler's type plate. Viessmann boiler repair, and every other Viessmann code.
Sources: the user guides and installation manuals of each Ideal range named, Ideal's Logic Combi and Logic+ Heat troubleshooting pages, and Viessmann's Vitodens instructions for each type named.
What causes F2?
F2's causes depend on the make, as the code covers two faults. The engineer follows each maker's manual, in this order:
- On an Ideal, a flame that lit and went out. Ideal's chart for flame loss asks first whether the boiler lights for a moment and then goes out. If it does, the engineer checks the electrode and its lead, then the condensate pipe and the flue for a blockage.
- On an Ideal, the gas and the ignition. If there's no brief flame, the chart starts with the gas pressure reaching the boiler. Next come the power from the main board to the gas valve, and the spark generator. After those come the electrode, the condensate trap and pipe, and last the gas valve itself.
- On a Viessmann, the water. The engineer checks the water level in the heating and the pump, and lets out any air in the system.
- On a Viessmann, the cut-out. The temperature limiter itself and its leads, then a reset. On a newer One Base boiler, the manual adds the expansion vessel's charge, the system pressure and the flow of water.
Neither manual ranks the causes by how common they are, so the list follows the manuals' own order.
Sources: Ideal's installation and servicing manuals for the Logic Combi2 and the Logic Combi ESP1 (the flame loss chart), and Viessmann's installation and service instructions for the Vitodens types named.
Worth knowing
Read the code out when you ring, with the type from a Viessmann's type plate. Viessmann's user guide says knowing the code helps the engineer come prepared.
What can you safely check?
Each make has its own safe checks for F2, from the maker's guide for householders. Never open the boiler's casing, and never touch anything that carries gas.
1. On an Ideal: is the gas on?
See whether the hob, or any other gas appliance in the home, works. If none does, or there's nothing else to try, look at the meter to see the gas is on. A prepayment meter needs credit, so see that it still has some.
Ideal's code list also asks you to see that the yellow gas tap under the boiler is still on. A tap that is on has its handle along the pipe. The list asks you to listen too as the boiler tries to fire, since a gurgle may mean a blockage.
2. On a Viessmann: what does the pressure read?
Viessmann's advice puts most boilers at 1 to 1.5 bar, with little or no heat demand. The user guide for a newer Vitodens says to top up if the pressure is under 1.0 bar, or to call in a heating engineer. Viessmann's pages show the filling loop's steps, with the boiler off, and ask you to read your own boiler's guide before starting.
3. Reset it once
The reset differs by make:
- On a Viessmann B1HC, once the fault symbol flashes and R shows, touch R for about two seconds.
- On a newer Vitodens, wait for the burner to cool, then hold the two reset buttons together for about four seconds.
- On an Ideal, Ideal's code list suggests a reset, but a Logic+ offers no Restart for Flame Loss.
If F2 comes back, stop and ring us.
Sources: Ideal's boiler fault codes page and its Logic+ Combi2 user guide, Viessmann's operating instructions for the Vitodens 100-W B1HC and the newer Vitodens, and Viessmann's advice on raising boiler pressure.
When should you stop and ring an engineer?
F2 calls for an engineer once one reset hasn't cleared it. Ring for one straight away at any of these signs:
- On an Ideal, F2 keeps coming back, though the gas works everywhere else in the home.
- On an Ideal, the boiler gurgles as it tries to fire, which Ideal says may mean a blockage.
- On a Viessmann, F2 returns after a reset. Its user guide says to call in the heating engineer.
- On a Viessmann, the pressure keeps dropping after a top-up.
- Going further would need the boiler opened, and Viessmann's guide says never to open it or take its casing off.
If you smell gas, leave the reset alone and open the gold "Smell gas?" bar on this page for the free emergency number. Otherwise, ring us, because finding the cause of an F2 on either make is our Gas Safe registered engineers' job. Boiler repair across London, every make.
The question we'll ask when you ring about F2
Our first question about F2 is the make, Ideal or Viessmann, because the make decides which fault F2 is. On an Ideal it is a flame that went out, and on a Viessmann an overheat cut-out that tripped. The next question depends on the make:
- on an Ideal, we'll ask whether the hob and your other gas appliances work
- on a Viessmann, we'll ask what the pressure gauge reads, and the type on the type plate
What changes the price of the fix?
The cost of an F2 repair depends on the make and the cause. Air or too little water in a Viessmann's heating may need no part at all. An electrode or a gas valve on an Ideal is a part to fit, as is a pump or the temperature limiter on a Viessmann. The rate is agreed on the call before anyone comes out, and no work is done until you say yes.
Do you cover my part of London?
Yes: we fix F2 faults all over Greater London, day and night, in every borough north and south of the Thames. Pick your side of the river to see the areas.
North of the river
Every borough north of the Thames: Barnet and Enfield at the top, Hillingdon in the west, Havering in the east, and central London in between.
South of the river
Every borough south of the Thames: Richmond and Kingston in the west, Bexley in the east, and down through Croydon to Sutton and Bromley.
Questions about F2
Can I keep resetting the boiler?
No, reset a boiler showing F2 once at most, after the checks above. Resetting several times in quick succession is something Viessmann's guide warns against, because a fault left unrepaired can put lives at risk. An Ideal brings up LC, or Too Many Restarts, after five restarts in 15 minutes. If F2 comes back, ring us, as the fault needs an engineer.
Is F2 dangerous?
F2 is a safety stop on both makes. An Ideal stops when its flame goes out, and a Viessmann's cut-out stops the burner when the water gets too hot. A smell of gas is an emergency, though. Leave the reset alone, and use the free number in the gold "Smell gas?" bar on this page.
Why has F2 come back?
F2 coming back after a reset usually means the cause hasn't gone. An Ideal's F2 may have any of these causes:
- a gas supply that drops
- a condensate pipe or flue that is blocked
- an ignition part that works on some tries and not others
On a Viessmann, the cause may be too little water, air in the heating, or a pump that isn't moving the water. An engineer tests each possibility.
How much does it cost to fix F2?
An F2 repair is priced on the make, the cause and any part it needs. The rate is agreed by phone, ahead of an engineer's visit. How our rates work.
Don't know what has failed? You don't have to.Ring and say what you can see or hear. Finding the fault is our job.
Calls answered 24 hours a day
A real person answers and gives you the rate on the call. No work starts until you say yes, and repairs are guaranteed for 12 months: parts, labour and any return visit.
