I have an unvented sytem (Megaflow). Few months back we discovered that the system kept on losing pressure (and hence the boiler shutting off). The loss of pressure is quite rapid - within 2/3 hours!
I was informed that the loss in pressure was due to a leak in the ground floor as there was no sign of leaks upstairs. Most of my ground floor is tiled so extremely difficult to locate the leak. Over the last 4months I have tried various means of locating the leak/leaks but to no avail. Finally I hired the services of a firm specialising in leak detection they use infra red cameras, sonar, etc). They have reported that they are 99% sure that there are no leaks. They recommend me to get someone to have a look at the Megflow system as they suspect that is where the pressure is being lost.
Before I go and do so, I should be grateful for your views and thoughts as to what are the probable cause of pressure being lost in the system (i.e not due to a leak).