POOR PRESSURE

[frixster]

Hello, can anyone help or have any advice?
I recently had a combi boiler fitted, and the old back boiler, fire and tank removed.
We have a new (1 yr old) shower and it works fine when nothing else is on (i.e. the washer, flushing the WC etc), but recently the washer was on when I was using the shower and the thermostatic switch kicked in and cut off the electric supply to the shower
After turning the washer off the shower worked fine, but the next time I used it, it was stoned cold.
I've checked the supply and theres 240v there.
Now, if the showers knackered, fair enough, but how can I increase the water flow so it doesn't happen again?
Its such a pain if someone downstairs turns on a tap whilst someone else is in the shower (it goes stone cold)!!!

 

[Nige F]

If you`ve got the instructions for the shower, there should be a resettable overheat stat somewhere........you could try piping the shower directly from the rising main where it enters the house...and maybe in 20mm blue plastic pipe IF it can be hidden....did the same here @ home ...Now I`ve got 2 mains into the house .1 does the garage tap and the shower.......laid a new one before the drive was done The existing copper one does the rest.........and if the copper perishes under the drive one day ...........the new plastic one is accesible under flower bed