Boilermate II replacing boiler return pump

Due to getting wet, the boiler return bump on my Boilermate II has failed. I can easily handle a pump replacement but unfortunately the two attached ball valves have also lost the will to function without leaking.

I posted elsewhere and got a lot of hate, both for the Boilermate, and for me wanting to repair it.

I've fixed this thing a few times (circuit boards, oventrop valve) and as the boiler is fine I'd prefer to fix this rather than replace the entire system.

Someone said that I could bung up the header tank and that would allow changing of the valves without needing to drain. I can't see an easy way to do this and it's hard to get to.

I've read that draining can cause other problems to show themselves (blocked header, feed, drain) etc.

So - question is - does it need fully draining/refilling to replace the pump&valves? OR should I just get the entire (21 year old) system replaced?

Ok so mine may be one of only a few remaining Boilermate II's.

I got someone out do do the drain and change the pump & valves. Luckily it filled-up fine and it's all working again. It lives to fight another day!