Hi John: I have had a sealed system in my work premises for some 20 years, purely for 16 radiators on the ground floor with a conventional vented system with 10 radiators and hot cylinder on the first floor. I have always had the same problem as you with the sealed system, and no sign of leaks. One important point is to make sure the pressure vessel is kept topped up - this should be shown to you by the installers. The reason for the boiler rattling will be because of build-up of gases which will accumulate in the high point or points of the installation. David -----Original Message----- From: access-uk@xxxxxxxxxxxxx [mailto:access-uk@xxxxxxxxxxxxx] On Behalf Of John Wilson Sent: Tuesday, April 08, 2008 4:04 PM To: Access UK Subject: [access-uk] O/T but does anyone on the list have an Ideal Isar combi-boiler? Hello All, Sorry for the O/T posting but I'm sure that some people on here will be able to compare notes and give valuable feedback. I have had an Ideal Isar combi-boiler now for a year and am of the opinion that the pipework may be leaking under the downstairs floor boards. Other people I have spoken to (but with different boilers) tell me that they rarely, if ever, have to top up the pressure in their central heating system. However, I find that I have to do this every three or four weeks. The pressure will have fallen from the recommended 1.5 bars to only 0.5 bars or even lower, causing the boiler to become noisy with a vibrating effect. Does anyone else find this to be the case with these boilers and systems? I am about to report it to the fitters but wanted to know what the norm for the frequency of pressure top up of these systems is firstly from any other users. All contributions appreciated. John. ** To leave the list, click on the immediately-following link:- ** [mailto:access-uk-request@xxxxxxxxxxxxx?subject=unsubscribe] ** If this link doesn't work then send a message to: ** access-uk-request@xxxxxxxxxxxxx ** and in the Subject line type ** unsubscribe ** For other list commands such as vacation mode, click on the ** immediately-following link:- ** [mailto:access-uk-request@xxxxxxxxxxxxx?subject=faq] ** or send a message, to ** access-uk-request@xxxxxxxxxxxxx with the Subject:- faq No virus found in this incoming message. Checked by AVG. Version: 7.5.519 / Virus Database: 269.22.9/1364 - Release Date: 07/04/2008 18:38 No virus found in this outgoing message. Checked by AVG. Version: 7.5.519 / Virus Database: 269.22.9/1364 - Release Date: 07/04/2008 18:38 ** To leave the list, click on the immediately-following link:- ** [mailto:access-uk-request@xxxxxxxxxxxxx?subject=unsubscribe] ** If this link doesn't work then send a message to: ** access-uk-request@xxxxxxxxxxxxx ** and in the Subject line type ** unsubscribe ** For other list commands such as vacation mode, click on the ** immediately-following link:- ** [mailto:access-uk-request@xxxxxxxxxxxxx?subject=faq] ** or send a message, to ** access-uk-request@xxxxxxxxxxxxx with the Subject:- faq