hot/cold water not "mixing"

[sjackie]

I have a mixer shower attachment coming from the taps in my bath, the problem is when you turn on the cold tap it seems to "override" the hot water and the shower goes freezing cold, you only need to turn the cold tap on a tiny bit for this to happen. Is this something to do with the way it's plumbed in? If so would it be fairly easy to fix (by a plumber not me !)

When you turn the taps on to run a bath it doesn't have the same problem.

thanks

 

[chrishutt]

This is a common problem. You have very unequal pressures, with cold off the mains (maybe 3 bar?) and hot fed from a tank only a little way above shower handset height (maybe 1 metre = 0.1 bar?).

You need fairly radical changes to your plumbing to get a decent shower. Best bet might be a venturi shower. Do a search on it for more info.

 

[sjackie]

thanks for that. the hot water tank is propably only about metre higher than where the shower handset is. If I had a new electric shower fitted would I still have this problem ? would I need a pump?

 

[chrishutt]

No, an electric shower would run off mains pressure cold water. However flow rate would be lowish (4 litres/minute max) and running costs relatively high, if you like long showers. Check out venturi showers - better flow and lower running costs.

 

[sjackie]

thanks, I did a search and got info on Venturi - it does look pretty good and doesn't look like it would be too difficult to install - cheapest place I found it was on Screwfix website if anyone else is interested.