Solar Thermal Problem

[blueplanet]

Hello

I just had a solar thermal system installed by Navitron.  It is an evactuated tube system with 20 tubes.  I have a south east facing roof.  However, it does not appear to heat up very much.  It has been sunny in my area for the last 2 days with the outside temperature reaching 24c.

I expected my 180l cylinder to have been heated to 60c at s2 during this time but it barely reaches 45c.  Should it be reaching 60c in a couple of hours?  It sees to me that there is a problem.

My aunt has a solar panel in the same area and her one reaches 60c very quickly.  How can I check if the system is working correctly?  I have spoken to Navitron and they claim it is working.