Problem with a Jaguar combi boiler. Help?

Question

I have a (quite recent model) Jaguar combi (heating and hot water) boiler, which has recently started coming up with an FO error code quite regularly. Turning the power off and on rectifies it temporarily but if we don't use the hot water for a while it reverts to this FO code again and the pilot light won't engage. While we can still get hot water, resetting the boiler every time you want a shower is annoying. Anyone know what's wrong?

Answer 1

the fo code is listed in the back of your boiler manual, this will tell you what the boiler tripping for. you will find the solution a lot easier if you know where to look. a lot of jag boilers stick on the flow pressure sensor switch this tends to give this problem described.

regards MR M Kirkham plumber

Answer 2

Check that you have the correct water pressure on the gauge. It should read between 1 bar and 1 and a half bar.

Check that the boiler Pump is working when the boiler lights up.

Answer 3

Make sure the static water pressure is correct. The dial on the front should show something like 1 or 1.5 bar (User instructions will tell you the figure and how to raise it). The best time to read and adjust this is when the boiler is cold.

Using the hot water, which heats the whole boiler, probably raises the pressure just enough to keep the boiler firing.