Posted: Mon Nov 09, 2009 8:10pm

Hi Tony, The 2007 calorifier is labeled Sigma Marine, another label says - Nautic Boiler model B03OUC 08 QUICK. sn-100003. photos show the pipes connected to lowest point on my calorifier. The blue pipe is the domestic cold 'in'. The red goes to a hole/outlet at the stern. Am I right in thinking the union with the red cap ( left hand side of photo ) is for pressure relief ? I thought it might have been for draining down. It will click round when turned ( anti clockwise .... I think ). Any idea what it is for ? Thanks Mark.

Posted: Mon Nov 09, 2009 8:12pm

Heres the other photo !

Posted: Tue Nov 10, 2009 10:22am

The thing with the rd cap is almost certainly the pressure relief valve that prevents excess pressure building up in the system as the water is heated and expands. The excess pressure is vented overboard. I would expect the outlet for that pipe to be well above the waterline so it may not work as a drain. The clicking is the valve lifting. This is done if the pump keeps cutting in and out because some scale has caught on the valve seat. Twisting the valve produces a flow of water to flush the seat. Tony Brooks PS To all readers if you want me to look at pictures do not post them on the forum. Email me and ask if you can send them to Tony@TB-training.co.uk. Then I will have full sized pictures to look at.

Posted: Tue Nov 10, 2009 11:35am

Thanks Tony, appreciated.