"Stevethefootycoach" wrote in message
ups.com...
Thank you all for your quick and useful replies.

I'll put a single impeller pump on the outlet side of the hot water
cylinder and let you know how it goes.

thanks again!

Check if the mixer has an integral pressure equalisation valve. If not put
one in directly after the pump.
http://www.plumbworld.co.uk/344-0000