Draining/refilling Combi system

[nitro23456]

Hi everyone

Apologies for basic questions but iv not done this before....

I have a combi boiler heating system I want to drain down to move a radiator downstairs.

1. Could I close all rad valves upstairs to save time/water draining and then only drain downstairs or would I be better doing it all?

2. I assume I cant use the boiler for hot water only if heating side drained?

3. I have an external (red) expansion vessel. Will i need to do anything with this when refilling?

4. Refilling is just a matter of opening the filling loop to 1 bar, then bleeding and rebleeding?

Thanks in advance

 

[mrStat]

1) If you are moving a radiator and pipework you need to drain the lot.

2) Correct. No heating or hot water until the system is back up and running again.

3) No. Personally I’d check the precharge pressure and top it up as needed just for the fact it’s a convenient time to do it, but no. Nothing else to do when draining.

4) Kind of, don’t forget to add inhibitor when filling and if you’ve soldered to flush out any debris in the pipework. Pressurise, bleed, pressurise, bleed, etc etc

 

[nitro23456]

Next silly question..... my boiler has a digital pressure reading, when boiler is off at the switch so is this display.

Therefore do i turn it back on just before refilling so i can fill to 1 bar or guess an amount of water before turning on (but risk too much)?

Also for 3 above, what should the precharge be?