Potterton combi 80 pump head change

[jacobball]

Hiya
Just a quick question:

I am going to change the pump head in my boiler as the pump is knackered. My question though is: Should I drain the boiler by closing the flow and return valves or should I drain the whole system down? I have heard the valves may leak when re-opened ? But draining down and refilling could take a while? What is the best way please?

Thanks for your help

 

[crashndie]

turn the valves off use the prv to drop the pressure valves should be ok its when the valves are about 8 yrs old you dont want to be messing with them

 

[lightning]

never drain a boiler through the prv as it might not reseat, close rads off drain down and refill with inhibitor.

 

[Tom1981]

The Combi 80 has a drain point to the right hand of the pump housing, just isolate the boiler.