The boiler runs but will not light up when the heating is on or the water is turned on ,The fan is running and speeds up when heating or water is turned on.
Is this a 77ff? This boiler sucks air in from outside through the fan. Take the fan out and you will probably find the blades are coated with dust & leaves etc. Clean this off and the fan should run at full speed. If it doesn't fire up then it's probably the air pressure switch
ps. Spray some wd40 on the bearings.
gleach, May 2007
Chances are you have either a faulty air pressure switch or an overheat stat has cut out. Neither are easy to test if you are not familiar with using a multi-meter or to be able to check the combustion chamber seals.
You can test for overheat failure by going through the pilot lighting procedure. If you can put the pilot out and relight it exactly as described by the instructions then the o/heat stat is probably o.k and it is more likely to be the a.p.switch.
If you can't light the pilot the correct way (i.e. no spark for pilot) then its more likely the o/heat stat.
There are other causes but none that you should be trying unless you have the neccessary equipment and knowledge.
T.H.S, April 2007
hi, i have the same problem, mine is a 77 ff combi and the pilot light remains but after a day when you put hot water or heat the fan will come on but the gas won't light up although the pilot light remains.
phil, April 2007
Which model ferrolli? Sounds like quite an old one if it has a two speed fan. Possibly a 76ff or a 77ff or maybe a Hawk. Does it have a permanent pilot light?
