I replaced my old shower recently as it had been having problems for a
couple of months and finally packed up, I had initially suspected a
water pressure change but then it packed up so I assumed it was just
past it. I replaced this with a Mira Sprint, it's fed directly off the
mains like the previous one. The problem I'm having with it is similar
to the one the original shower had before it packed up, in that I can
have either hot water with next to no flow, or freezing cold water with
a decent flow, which is the same problem which affected the previous
shower before it packed up. The instructions on the Mira tell you to
commission it by switching it to the lowest power and then working up,
however, only on the highest power is there any heat at all, but this
reduces the pressure too much. I guess it could be due to the mains
water being very cold at this time of year, but I wondered if there is
any way of improving the heating capability of the shower, it seems
that adusting the control changes not only the amount of heat it puts
in but also the flow, so I wondered if it's possible to get the thing
to put more heat in at a higher flow rate than it currently does. Any
ideas?

wrote:
I replaced my old shower recently as it had been having problems for a
couple of months and finally packed up, I had initially suspected a
water pressure change but then it packed up so I assumed it was just
past it. I replaced this with a Mira Sprint, it's fed directly off the
mains like the previous one. The problem I'm having with it is similar
to the one the original shower had before it packed up, in that I can
have either hot water with next to no flow, or freezing cold water with
a decent flow, which is the same problem which affected the previous
shower before it packed up. The instructions on the Mira tell you to
commission it by switching it to the lowest power and then working up,
however, only on the highest power is there any heat at all, but this
reduces the pressure too much. I guess it could be due to the mains
water being very cold at this time of year, but I wondered if there is
any way of improving the heating capability of the shower, it seems
that adusting the control changes not only the amount of heat it puts
in but also the flow, so I wondered if it's possible to get the thing
to put more heat in at a higher flow rate than it currently does. Any
ideas?

It is even simpler than that - the heat level is kept constant and the
temperature is controlled by adjusting the flow. The faster the water
flows the less time it has in the heater to warm up and so the colder
it comes out. The slower the flow the longer it stays in the heater so
the hotter it gets.

If you have either cold or scalding you probably have either high flow
or eff-all. I suspect that there is something reacting to the flow and
changing the pressure - maybe an air-lock could cause this? What
happens if you turn the shower to a mid-possision then get someone to
gradually turn up the kitchen cold tap? This should change the flow and
also the water temperature.

Another option is that you may be using the wrong shower head - most
electric showers come with a head that is matched to the shower,
changing this for a nice fast-flaw one (or even an easy to clean head
with rubber bits) is likely to cause much grief!

wrote:

mains like the previous one. The problem I'm having with it is similar
to the one the original shower had before it packed up, in that I can
have either hot water with next to no flow, or freezing cold water with
a decent flow, which is the same problem which affected the previous

Yup, that is about what you get from an electric shower... it will be
worst at this time of year with the supply water being particularly
cold. Even a 10kW shower will only give you 4L/min of water at a usable
temperature this time of year.


--
Cheers,

John.

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