3 port valve - yes again i know, but plz read

[Heyyouitsme]

Right guys,

i have the usual heating probs, ie heating only works when hot water timer starts or if i put hot water to constant, and then it does not turn off, anyway i know this is a problem with my 3 port valve. I am awiaitng my new valve as we speak, but i think my current one is not standard. All the other ones i have read about on here appear to have a shaft that is rotated 40deg either way frm the mid position, my valve (drayton flowshare 2) has an arm the moves side to side selecting the flow as oppose to a shaft that turns. So i am assuming that i will need to replace the whole valve and actuator, this again is not a big problem by the looks of it, it seems that someone has thought about this when the system was installed, and i have shutoff valves on all of the pipe work except from the hotwater tank ( i have a vented system, boiler(nt combi) hotwater storage tank, thermostat and header tank in the loft)
would i be correct in assuming i close the 2 valves i have (heating pump and boiler - obviously turning boiler and pump off) get up into my loft and turn the coldwater feed off to the header, or prop the ballcock, and then drain down the tank using a hot tap to empty. then replace my 3 port?

 

[ollski]

No prop the f & e ballvalve and drain the rads to below the level of the valve. You do have two tanks in the loft don't you?. Actuators only are still available for the flowshare 2.

 

[Heyyouitsme]

tried a few peeps yesterday and they told me they were showing in the catalouge but had been discontinued, if its bene in since my house was built (10yrs ago) id gess changing the whole lot for a new one aint guna do no harm, the valve is in my airing cupbopard and is about 3 ft above floor level so is above all of the rads anway, and yes there are 2 tanks in the loft.

 

[Heyyouitsme]

update:

Whoow 20mins, jobs a gud un. all replaced and working well )