This job can rapidly escalate into a complete ballache, with leaking service valves/perforated vessel diaphragm/chewed up loop valve, distorted plastic manifolds, I've also had a few plate hex's that then fail with let-by
from DHW to the heating side etc. With Worcester's fixed price deal they'd change the whole bottom end for an easy time (or they used to).
The pipework normally enters the boiler via upstands so you leave the flow/return service valves well alone and work on the boiler with the rads/pipework full of water.
Even then I've had the valves leak as soon as the pressure is dropped and it's pot luck whether they will seal again at 1 bar.
Only isolate the cold domestic water inlet valve, no need to drain down.
Remove the whole controls panel.
from DHW to the heating side etc. With Worcester's fixed price deal they'd change the whole bottom end for an easy time (or they used to).
The pipework normally enters the boiler via upstands so you leave the flow/return service valves well alone and work on the boiler with the rads/pipework full of water.
Even then I've had the valves leak as soon as the pressure is dropped and it's pot luck whether they will seal again at 1 bar.
Only isolate the cold domestic water inlet valve, no need to drain down.
Remove the whole controls panel.
