Hiya - switching CH back on for the first time this Autumn.
Pump is Grundfos SuperSelectric 15-60.
I've checked there's volts on the pump.
Manufacturers data says, take out the screw plug on top of the pump body, then press in and twiddle the rotor with a 3mm screwdriver.
Tried that - rotor locked absolutely solid.
Checked the identical pump in the system - and that moves easily.
So - ideas to try next?
Brute force?
Strip part of the pump?
Don't bother and buy another?
In several systems I've dealt with, the pump gets stuck every year. This was with pumps in the vertical position so the spindle itself is horizontal and tends to move toward the cover cap and then get slightly glued in place by precipitation. Generally with the motor on, all you need to do is take tha cap off, find a soft (a pencil or dowel) drift and give the centre of the spindle a smart tap and the impeller will move back and start turning. Then you run the pump of fairly high speed until water starts to flow from the cap hole and put the cap back on. Sometimes, if the impeller is particularly prone to ride up, I have whittled a nylon plug to hold it back a bit.
A word of warning - not sure if it applies to all - one pump spindle had a tempting 'cross head' screw impression on it, but it *isn't for turning* and it is *ceramic* the spindle is thus very easy to splinter with a screwdriver. But a smart tap with something less hard gets it running nearly every time. Hundreds of Grunfoss pumps must get thrown away this time every year when all they need is a smart tap on the spindle, if my experience is anything to go by.
S
Definitely worth stripping before resorting to replacement
Fantastic! Worked first time.
That's a TOP TIP. Deserves to go in the wiki somewhere.
I changed a couple of pumps before realising the problem was that the shaft was horizontal. It is fitted into a horizontal length of pipe and since repositioning the pump, so that the shaft is pointing down at 45 degrees, it's run for many years, with no further problems.
Andy C
IIRC the destructions for the Grudfoss circulators they do say not to install with the shaft axis horizontal or with the motor unit lower than the pipework. I have two here, in vertical pipe runs, never given a problem but then they don't sit unused for months on end during the summer, even the CH one only gets a few weeks rest if that. Which reminds me I haven't excercised the gate valves for a while...
Well mine has not got stuck recently, not sure if that is because the axis is now no longer horizontal or I converted to a fully pumped system!
YW.
In fact, if you strip a spare pump down, you'll see there isn't much inside to go wrong, and one just comes a cropper by not realising how brittle the spindle is, and taking appropriate care.
I once had one where the impeller veins became filled up with little polystyrene beads from some old ceiling tiles that had been used to cover the header tank. Otherwise, what usually seems like a pump problem - rads not getting evenly warm quickly - turns out to be a three port valve problem, not allowing the full flow from the pump through the CH part of the system. That is probably the second most common reason for pumps being changed unnecessarily.
Cheers,
SHomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.