Every 3-4 weeks, pressure drops and no heating/hot water

[cronshd]

Hi

Preamble

This is a continuation of a previous thread http://www.ukplumbersforums.co.uk/c...h-potential-leak-expert-required-complex.html

Firstly, I would like to publicly thank Destroiyer2813 who came to my house and spent some time looking at the original problem and noticing a tiny amount of water in corner on the floor. It is not often someone will do that kind of thing and be extremely helpful.

The end result of that was that a portion of floor was dug out and the leak found. It wasn't the UFH, it was the copper piping which had failed. That was over 3 weeks ago. So the floor was sorted fine, and 2 plumbers ensured the UFH was all rebalanced (my words) and working fine.

End of preamble

Current problem

The problem is that the Ideal+ boiler loses pressure every 3-4 weeks and we wake up with no heating to UFH, rads and no HW.

I had assumed that it was the leak which had been causing this - but now the leak is solved, it must be something else, as it happened this Monday.

Any ideas on what to look at?

Thanks, D