i keep having to top up pressure , had new safety valve fitted but boiler keeps going over pressure therefore blowing off safety. I think expansion tank is not working. How do i repair/fix?

Gerald Logan, October 2007

dhw heat exchanger passing water from cold side

carl, May 2014

isolate boiler underneath on htg pipes, empty boiler through blow off and connect cycle pump to valve on red ex vessel. keep pumping as this will be full of water until 12psi is in the vessel. rotate red knob on blow off to reseat it, opev htg isolaters under boiler and pressure upto 1.2 bar on guage via filling loop. dpmartin17@aol.com

paul martin, October 2007