Injection Tee (Plumbing question)

plumb1_2

Heatranger Models 216SFW & 355SFW

With these models it is normal installation practice to pump-assist the central heating circuit, whilst retaining gravity circulation for the domestic hot water pipe-work.
The heating pipe-work should be a two-pipe, small bore system with the radiators having the appropriate control valves and lock-shield valves for balancing. The control valves may be thermostatic, but it is recommended that at least one radiator should remain in operation with a manual valve, to serve as a heat-leak
An injector tee (supplied with the Rayburn) must be fitted as shown below, to ensure that the gravity hot water circulation continues even when the pump is in operation. Note the correct position for this fitting. Drain-cocks should be fitted at the lowest points of the system.

plumb1_2

plumb1_2

plumb1_2

Mike4 wrote:

if the cold fill and open vent pipes should ever freeze, the range will turn into a bomb.


M4

It is not a solid fuel appliance(gas)
if the F/E were to frezze in any(gas,oil, solid fuel) open vented system it would explode, in extream case. More likely to evaporate water(steam) and boil dry, ending in cracked heat exchanger.