Some ten years ago maybe, my central heating pump died. It’s an ancient one-pipe system and the pump looked like something out of a nuclear submarine (seriously, it was a foot across and had alternate wiring connections for 3-phase). I replaced it at the time with a “Wilo Gold 50″ pump (and about 6” of copper pipe). This has now died (probably full of shite I’m guessing).
Looking at replacements and the choice is bewildering. In particular, they all seem to have clever variable settings which mean nothing to me. Take this:
http://www.anchorpumps.com/media/downloads/2401/CP%2050-60%20Operating%20Manual.pdf
Control modes
Variable differential pressure (?p-v):
The differential-pressure setpoint H is increased linearly
over the permitted volume flow range between ½H and H
(Fig. 2a). The differential pressure generated by the pump
is adjusted to the corresponding differential-pressure setpoint.
3 speed stages:
The pump runs uncontrolled in three prescribed fixed speed
stages. (Fig. 2b).
What does that even mean? How should I be setting it to, well, just pump? I don’t want to set it too high and flood the house, nor too low as it doesn’t actually do anything. I’ve no idea what a H is or why I might want half of one.
Are these things serviceable? Is it worth me trying to take it to bits or should I just skip it and replace? If so, what with? I was looking at this: http://www.screwfix.com/p/grundfos-ups2-15-50-60-central-heating-pump/42635 – as I believe Grundfos are well regarded, and it’s supposed to be a direct replacement for the Wilo, though whether it’s a direct replacement for my Submarine Surplus who knows.
Cheers.