CharterGAS

hi jaded
i look after 14 ideal istors which are basically the same boiler except is has an unvented cylinder under it. I have major problems with these boilers and they are only just 2 yrs old.
I have been to hull to Ideal and did their training course on the ideal and the guy taking our class specifically said that if you cant shift the heat away from the boiler then you will get loads of different fault codes which are actually wrong ie flame rec fault code .

since taking the course i have returned to these boilers and who ever put them in only set up for 11 degrees temp differential and the radiators not balanced properly. Since adjusting to 20 degree differential and setting up the rads correctly the boiler now actually condenses and since then had no problems.

These are my experiences so hopefully they will help you too.

re max flow temp_ is the maximum temp it will put out to the radiators, but with big radiators you don't need to put it at max flow - in Germany they are restricted to 70 degrees max flow temp!! i have loads of boiler out there that have a max flow temp of 70 and even less, they are also used with weather compensation. I have never had any problems with heating the rads .

There is a belief that condensing boilers should have the flow and return temp low as possible to suit the system to prevent long term problems with the boiler particularly heat exchangers. this is evident with baxi releasing a boiler with a plastic heat exchanger.

So really the best way to set upi your condensing boiler is to have 20 degrees differential temp, down rate the boiler if possible to the correctly calculated heating load
and if you are not using weather compensation then limit the flow temperature to 70 max!! you will find it will be way more efficient.

As per heating times in the proper calculation they should have allowed for rapid heat up time too so it may very well be a pipe work issue. is the flat a new build??