I've just replaced a monoblock mixer tap in a kitchen and the new tap has lost about half of the water pressure to the Hot tap.

I've drained the system again just in case it was an air lock, taken new pipe work off to check for blockages, stripped tap down to check for blockages but nothing.

The other taps on the same level are all good so it's something with the new taps but I can;t figure what. Any ideas or am I missing the real obvious here.

It's in one of those upside down houses where the living room and a bedrrom is up stairs and the kitchen, bathroom and remaining bedrooms downstairs.

The hot water tank is downstairs on the same level as the new kitchen taps and there is no loft and no CWSC.

Any advise is VERY welcome.

Many Thanks

> the storage tank is downstairs
no loft and cws.

that don't make any sence. you must have a cws somewhere

but your fault is with your tap. if you are a gravity hot water as it sounds like it.
you have fitted a tap that only works on mains pressure above 1 bar.
a gravity fed tap will work on around 0.2 bar.
read the mi to see what min pressure they recommend.