Hi,
I now need to fit a pump and thermostat to an existing gravity fed HW system (gas cooker/boiler cuts out occasionally before the tank is really up to heat, so I suspect the gravity loop isn't that efficient at moving the water round - it was OK through last winter, but we've had a few cut-outs this summer) So... Can anyone suggest where to get the thermostat from? I've only found tank thermostats when looking online and really need something that I can fasten round the 28mm pipe that comes out of the unit, with normally open contacts, which will close (ie turn on the switch) when the pipe gets to a certian temperature (thus supplying power to the pump) and breaks the contact when it falls to a preset temperature (ie. some time after the boiler is turned off)
Also, the pumps I've seen (standard CH style pumps, any to avoid?) all seem to have 22m connections, but I've seen isolating ball-valves which are 28-22m conversions - I presume this won't really have any effect on the flow through the system, given that it'll now be pumped...
Thanks for any advice,
Gordon