Just had a Potterton Suprima fitted to replace an old Servowarm, plus doubling of rad. output downstairs (to 23k BTU). It needed some extra piping around the HW tank/motorisied valve/pump (replaced & re-sited from inside the old boiler). Although the rads have no air in I am suffering from horrendous bubbling & whooshing once the water heats up. After a while there is a strong siphoning noise which tends to quieten things down, but it always comes back. Same noises in the HW tank when only that is on. I did express concern that the 15mm pipes supplying all the downstairs should be 22mm but the plumber said an uprated pump should do. He seems to think it must be to do with the old Servowarm pipes he can't see. I'm sure there's more to it. Any ideas?
Also the boiler seems to be seeping a little water from within the main casing. It couldn't be condensation could it?
Also the boiler seems to be seeping a little water from within the main casing. It couldn't be condensation could it?
