IDEAL ISAR HE35 Problem

I moved into a new build in Sept 2007 and ever since I have had problems with my boiler.

It makes a banging sound then an error message of L9 appears, I reset the boiler and I get alternating 0 and 3 dashed lines and the boiler is roaring like a jet plane (error code is not in the manual). After approx 60 mins the boiler resets itself and works again for another 30 minutes. This continues till the heating goes off by the timer.

An engineer has been out 6 times and replaced all the electrics on xmas eve last year and I am still having the same problems. When the problem occurs I have no heat or hot water, the pressure is at 1.5 bar and has dropped to near zero twice over the last year.

Please help I have a new baby and I am being messed around by the builder and the engineers that come out!

The boiler is overheating. Does it only do it when heating on or when hw is being run?
The L 9 fault code is an overheat and on the new Orange Pcbs there is a temp delay to stop customers repeatedly hitting reset resulting in hex bursts.
when this happens you will get 3 horizontal lines in the display. Check your rads to see if they all have thermostatic valves (bigger valves with numbers on).
If they do then that is the problem after 30 mins the rads are shutting down as rooms are hot enough but boiler has nowhere to pump heat to. You should have one rad without a valve(or 10% of the heating load).
If there is one rad without remove the plastic caps of the rad valves and with a spanner turn both valves anticlockwise until fully opened.
If it is doing it on heat an hw then the pump will probably be goosed or the system pressure will be low causing an overheat as not enough water in boiler.
When you put water back in does the gauge rise ok? As they can stick showing 1bar when actually empty.
Let me know how you get on!

The builder should have a 2 year NHBC warranty that is covered by Ideal engineers.
Is it Ideal engineers that come out??
They should know the boiler inside out and that is a relatively easy fault to diagnose and repair!

I cant answer your questions but have a look at Ideals web site

http://www.idealboilers.com/

At the bottom half of this page is an online fault finding guide which may help?

a common problem. these boilers are not fitted with a bypass. either fit auto bypass or make sure that 1 rad has both of it's valves fully open

It only occurs when the heating is on.

I do have the valves with the big numbers on as you put it on all apart from 1 rad.

I do see the gauge going up for the pressure when i top it up.

Thanks for you help, I am away for the weekend so cannot try what you have suggested.

In the past it hasnt been an Ideal engineer coming round, however after a heated dicussion with the developer yesterday an Ideal engineer is coming round on Monday, hopefully this will be sorted once and for all.