This is quite normal for electric showers as the flow rate is seasonally affected. The colder the weather (hence the incoming water supply is colder), the lower the flow rate. You should notice an improvement in the Spring as soon as things warm up. If the flow rate remains low then you may have a problem and it's best to ring the Mira Service Department on 0844 571 5000 for advice.
Bob The Builder
January 2011
howtomendit.com for free repair help, information and advice.
