DIY Doctor UK DIY Forums

Hi all,
i need a bit of advice, i want to fit a thermostatic mixer shower above my bath, problem is the cold water is really powerful but the hot seems less powerfull ? even though the hot everywhere else in the house is just as strong as the cold ??? its a fairly new house (4 years old) with a combi boiler set to 1.5 bars.
Should i just fit it by coming off the bath pipes and see if its ok and if not fit a pump after?
the hot water in the bath has always been like it, it doesn`t trickle out but its just not as strong as the cold.
i`ve asked in b&q etc all they recommend is an electric shower, i would really prefer a mixer though.
any ideas?
thanks
Craig

The 1.5bar on the boiler has nothing to do with the water pressure that's for the pressure of the heating system, not the taps - and mains cold water cannot be pumped - so no you cannot fit a pump later.

You need to find out the flow rate on the hot water, it will tell you in the boiler manufacturers instructions what flow rate the boiler can heat - but depending on the state of the pipework and the internal parts of the boiler eg blockages and limescale the flow rate could be reduced.

If the flow rate is poor you can try to rectify it by replacing or cleaning heat exchangers and filters etc. But with a poor flow rate there's no point in fitting a thermostatic mixer shower and an electric may be the only option as you do not have stored hot water that could be pumped.

Hope this helps

I would go ahead and fit a thermostatic mixer.The majority of these mixers are compatable with combi boilers and, therefore,can cope with large differences between hot and cold inlet pressures, sometimes as much as a factor of ten.Just ensure of its compatability before purchase.

thanks for the replies i`ve braved it and gone for a mixer shower, so far so good, will let you know of any hiccups!