Posted: Mon Aug 27, 2012 8:32pm

I am plumbing up simple heating gravity flow system. I just wanted to check the connections to the expansion tank. Some books show an expansion/ feed tank using just one pipe connected at the highest point in the system. ie from the top of a radiator to the header/ expansion tank. sketch plan A I have also been told to run one from the cold return to the tank bottom and one form the hot, to flow up into the expansion tank. plan B I would be very grateful for a prompt reply from anyone as I am just about to reach that point in the system. thank John

Posted: Tue Aug 28, 2012 8:51am

Dear John, if you want me to look at the pictures you will have to email them to me directly. Tony@TB-training.co.uk but I will not have time until this evening. You need to consider two things. 1 Filling the system and both will do this adequately but I would put the cold feed into the lowest part of the system. 2. venting the system of air and also, far more importantly, steam and boiling water if ever the system should boil. I would want minimum restriction in this pipe so would T into the hot outlet of the stove and run it into the top of the header tank above the water level. However this could result in showers of rusty water, antifreeze and steam all over the inside of the boat. I would prefer a (say) 15mm pipe running from the highest point in the system (often at the front of the boat) and vented through (say) the front bulkhead above the header tank level. Then if the system did boil the steam etc. would be vented overboard where it would be easier to clean up and with less danger of scalding anyone. Are you aware of the new advisory BS for stove installation in boats? Tony Brooks

Posted: Tue Aug 28, 2012 10:00am

Thanks Tony, how do I get you email address ? John

Posted: Tue Aug 28, 2012 5:33pm

As per my answer above: Tony@TB-Training.co.uk