simple plumbing question re water turn off

[lockwise123]

hi
many years ago i put in a mira 88 exposed valve (used in conjunction with my old back boiler setup) - recently i had a combi boiler installed and the mira 88 is not great but it seems mira 415 is best suited to a combi boiler setup.

anyway, thats neither here nor there. In order to remove old 88 unit i of course have to switch off water to it. Alas although the cold feed to the mira has it's own stop valve, the hot pipe to it doesnt.

So is it ok to turn off the cold water at the mains then drain shower until water flow stops? But more importantly, when i turn on the mains supply again do I need to do anything to the boiler or will the water find it's own way thru it etc?
thanks

 

[JCplumb]

Yes, you don't want your combi trying to heat up a dry heat exchanger though so best to turn the combi off until you have flushed the pipes after fitting your new shower.

 

[lockwise123]

thanks

so in short.....turn off mains, turn off combi, drain shower head, remove and refit new shower valve, turn on mains, allow water to flow for a while, turn on combi?

 

[ShaunCorbs]

yes you can turn the boiler back on once you have cleared the air out the hot taps / showers etc

but
turn boiler off
turn mains off
drain shower head,
remove and refit new shower valve,
turn on mains,
clear air
turn boiler back on

 

[lockwise123]

thanks guys

i might take the opportunity once water is off and drained to pop a valve on the hot pipe leading to shower (it's plastic pipe).