Where to put booster pump?

[Ivan Dobsky]

I bought a pump to boost the pressure to our hot water, mainly because the missus wants a mixer tap on the bath, and we haven't got enough head to feed it properly. My original thought was to have it near the hot cylinder near the floor somewhere, with a non-return valve on the expansion pipe, but I'm not sure if I have enough space to get the pipe cutter in. I thought it might also go in the loft on the outlet of the cold water tank, but I'm not sure if this is sensible, given that there is now going to be a hot water tank in between the pump and the taps (and they might make it less reactive); plus, it gets very cold up there in winter (maybe even freezing). Would putting it in the loft be workable? You'll have guessed by now that I would prefer to avoid cutting a hole in the cylinder, and feeding it from that. But I will do, if it's absolutely necessary.

[Ivan Dobsky]

Oh, hang on... If it's in the loft, what's to stop it just pumping water through the expansion pipe all day?

[Tim+]

Nothing. That's why you don't try pumping *into* a vented tank.

Tim

[Bob Minchin]

Don't forget for your mixer to work properly, you need equal pressure on the cold feed too. If your "mixer" is not a real mixer but is just two taps leading to a single spout with insufficient opening to suit your gravity feed DHW, then get a mixer that is designed for your sort of plumbing. Fitting a pump is just a bodge.