My boiler ignites 3 times then goes off but the boile people came round and said it was the switch but after they went we turned the switch on and it worked but it goed on for like a minute and goes off i dont know what to do? We got a new board put in 3 years ago? its quite annoying because i have asthma which means the cold affects my chest.
If you get good ignition and the boiler's ignitor stays on the entire time even after you have flame, then your flame sensor or controller is probably broken.
Otherwise, you have a mixing issue. Either not enough air is being moved by the fan or oil is not flowing sufficiently, possibly because of issues with the nozzle.
The 3 times lockout is a safety feature that keeps the boiler from filling up with unburned oil that possibly ignites in an undesirable way.