We have a Salamander CT55 Positive Single Shower Pump 1.67 bar fitted at the base of our hot water cylinder, it was fitted because we could not get any water pressure to our new shower, since the pump was fitted it works great for all the hot water taps in the house, but we only get a trickle of water from the shower, if we open the wash basin hot water tap which is situated next to the shower, the shower does produce a little more water.
I contacted Salamander pumps to get help with soeting this problem and their reply was:
Salamander recommend fitting an RCM3 to the top of the pump in order for it to work correctly on the shower mixer valve.
What is a RCM3 and where do I get it from?
I have a used one you could purchase if required.