Shower Pump Issue

[edcaporn]

Hi,

I have had a new techflow shower pump Qt80 installed (2.7 bar) replacing an old smart showers one (2.5 bar)

The hot water pressure is very weak from the new pump...it starts with a surge and then gradually dies off. The cold water pressure is fine.

I did not have this problem with the old pump.

I have had three plumbers (including the one who installed it and the pump manufacturers plumber) look at it and none of them can answer the problem.

The system is a normal cold tank in loft and hot tank in cupboard. The pump is installed about 1 metre away from the hot water tank and about

0.75 metre below it.

It is an Essex flange

the shower unit is not at fault as we have taken it off and checked it with the water coming out the wall

we have swapped the pump round and the cold comes out fine from both sides, so it is not a pump problem.

Whats really strange is that this problem did not exist before...

Any help is much appreciated as I am pretty desperate!!

[Burlington Bertie]

Two things from my experience.

One was that I got an air lock in the pipes from the pump. My pump serves two showers and pipes run overhead in the loft to deliver to the second shower. It took quite a while to get the air out.

Secondly there were some isolating valves hidden in the wall underneath the mixer unit. I actually took the step of fitting a new pump and it still didn't work right. Could you have these too and they've been turned down during fitting the new pump? Or might it be simply that there are some other valves on the pump itself or on the cylinder that haven't been turned back on fully yet?

[FKruger]

Could it be overheating? The hot should be no hotter than 65 c. If you lower the thermostat on the cylinder does it improve?