Shower Problem- too hot or nothing at all!!!

[AndyH]

We have recently had a new bathroom installed. However although the thermostatic shower (Mira) worked sort of ok to start with, we now find that sometimes we get no flow at all, other times it becomes scalding hot once all the water in the pipes has run through. the pressure/flow is always low.

We have a condensation boiler. The cold water tank is in the loft and the hot water tank is in the airing cupboard (same floor as bathroom).

The hot and cold flow to the bath, sink and toilet is fine, but the hot is less than the cold.

Before the refit the old shower did work. There is an old shower pump (twin impellor)installed but has never worked since we bought the house.

Do we just need to install new pump or could there be other problems?


Very grateful for any advice,

Andy.

[stoneyboy]

AndyH,
You should get the installer back to correct this problem if the installation is still under guarantee.
The erratic hot water may be due to an airlock or the pipework may not have been flushed during the fitting of the new shower - debris will stop the thermostatic mechanism working.
end

[plumbbob]

These symptoms are classic for a reversed feed input. (The hot and cold pipes are the wrong way round.) The shower is either freezing cold or red hot.

To discount this, feel which input side of the shower is the hot. Normally it is the left hot and the right cold.

[AndyH]

Thanks for the advice.

After reading Stoneyboys post we decided to bleed the system and removed the shower head and lowered it to floor level. After a few seconds of spluttering the water started to flow, bothe hot and cold. So refitted shower head and all is fine. Still think we need a pump to increase pressure.

Thanks again for the advice. should have tried it sooner!