Have fitted new bathroom suite together with taps and mixer shower. The hot water pressure coming out the tap is non existent (dribble) also hot water does not passs through shower mixer. House has combi Baxi 40 fitted. Bathroom is located on first floor.

Shut the water off to the valves and open them up. Check the aerator screens on the faucets that have them. After you get the valves open and the cartridges removed check and clean the inlet ports on the cartridges. Before you button things up turn the water back on the flush out the supplies and the valves themselves. Now, reassemble and test. To tell you more you will have to scan the cutaways of all the valves in question and send them to me. Since this's a new installation I assume that you still have them. Good luck, Tom