Hi All, First post here, so hoping someone can help me. I'm not a plumber, but an avid DIYer and keen to work out things for myself. Our house has two power showers fed from the same pump in the airing cupboard. We have a hot water tank in there and two cold water header tanks in the loft - the second one apparently just feeding the pump for the showers. The problem is that whereas both showers would need the mixer/on-off tap set to at least half way to get the shower to a suitable temperature (it's been that way since we moved in 2 years ago), very recently it's suddenly changed so both the showers are ridiculously hot unless you only turn the tap on less than a quarter, i.e. where it would have been only luke warm before. I've checked the temperature of the hot water feed and it's around 60 degrees, which is what the thermostat on the hot water tank is set to, so it's not the hot water being too hot - it's the cold water not having enough pressure I assume. I've been up in the loft and worked out that the cold feed for the pump comes from a secondary header tank, which is fed from the bottom through a short pipe from the main header tank next to it. I cant see any restrictions to flow, though both tanks have loads of white stuff at the bottom - more so the secondary tank, which just has one feed in from the main tank and one feed out to the pump. So, any ideas why the showers are running too hot? Pump isn't making any unusual noises. I've got another issue, which I don't believe is connected (although it happened about the same time) with the central heating pump being on 24/7 even when the heating is off - I'll post that separately.