1. B

    Replacing failed Danfoss 103 timer

    Hi, My flat has an old pumped central heating and gravity hot water system controlled by a Danfoss 103 electric-mechanical timeswitch. [Correction from ianmcd, below: It is not gravity HW. It is an open vent system with pumped HW]. No room thermostat. Hot water and heating cannot be switched...
  2. P

    Pex pipe-boiler: aerial distance

    I am adding radiators to my 2-pipe pumped, vented central heating (UK). The whole piping is copper 22mm and microbore, and I'm extending it with 15mm pex barrier pipe graded for central heating. I know that the first bit of pipes connected to the boiler must be copper, which is the case...
  3. M

    Programmer - gravity or pumped?

    Hi Just replacing my 2 channel programmer as the old one has failed. New one is a Danfoss Randall FP715SI (previous Sunvic select 207 XL). On the back of the new one (and old) are 4 binary switches, one to select gravity or pumped system. We have a Potterton statesman oil-fired boiler, the...