I'm trying to help out the old lady we keep an eye on over the road. I popped over just now and for some reason when straight to the circulating pump. It's a Myson Unit 3 and if you undo the thumb knob at the end of the pump spindle, pull it out and try to turn it, it will turn one way *just* (with my fairly big / strong hands) but not the other at all. Turn the power on and it still won't spin or even try to (but you can feel the electromagnetic 'difference').
So, presumably we have a seizing pump and from a quick Google the Grundfos 15-50 seems to be suggested as a replacement. However, they aren't as cheap as the alternatives you can get from the sheds so I wondered if you are just paying for the name?
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speed is the essence here so something I could pick up locally and asap would be handy.
As an aside, I've been able to turn the isolation valves (good old Leatherman PST II) and I've located a drain c*ck if it comes to it.
If the isolators do turn, might they not still isolate and if so is it general practice to change them at the same time?
I don't know enough to recommend a make, though personally I'd always pay a bit more a good make but just thought I'd mention, that I changed the pump on my system a couple of time before the penny dropped that the problem was, that the shaft was horizontal ! Since mounting it at 45 degree, the most I could manage, it's run now for quite a few years with no further failures.
Oh, I don't question your observations, just that it doesn't seem to be in-line with the general advice. But hey, you might have uncovered their way of making these things fail early. ;-)
Unfortunately, I don't have much of an option in this installation as the pump sits on a bit of vertical pipe ... ;-(
IIRC what they don't like is the "dry" end down in any shape or form.
The Brochure .pdf link on here:
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the installation instructions which indicate that the best installation position is shaft dead on horizontal or a little up at the "dry" end. Dry end down is bad news, so is vertical. Also pumping down is not recomended, though the problem there is trapped air.
If money is a problem It may only have some crap in it. If you remove the pump head (the four screws round the motor) you may be able to clean it up an free it off. (Leaving the body in position) You will need some form of jollop on the joint when you put it back. The bearings BTW are water lubricated.
The isolating valve(s) might well pass a bit but not usually enough to stop you doing the work. They would only need changing if they leak from the valve spindle after you have finished the job. This doesn't happen often.They are quarter turn to operate.
Depending on the pipework layout, you might get some air in the sytem & have to bleed a radiator or two.
Are they gate valves or ball valves? I'd almost put money on gate valves either not turning and/or not shutting off enough.
I also expect that the orginal insaller used fibre washers between the pump body an valves as well. These will probably have leaked just enough to cause the pump body to corrode and weld everything together. I've had to cut pipes above and below and remove the whole lump before now and even with the lump held in a vice and good grip not being able to shift the flange nuts at all.
When refitting use ball valves (assuming that the ones there don't work), synthetic washers and a smear of silicone grease on the mating faces and thread. This will ensure that you never have to replace the pump again. Use gate valves and fibre washers and it'll fail within 2 years and the gate valves will have siezed/not seal, again...
I don't think it is. I've been looking about on the Interweb and you can go from 38 to around 100 for a Grundfos. I ran it past her and she said she would be ok with any.
Oh, ok. I might do that first.
Ah (makes sense).
Ok.
Right, well as I was working them round they did weep a bit but seemed to stop once I stopped turning them?
Understood, although they can be turned right round can't they (I think these did)?
Can you see signs of that (rust on the body under the top nut) in this pic?
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These will probably have leaked just enough
;-(
I have blowlamp, hammer a cold chisel, Bosch 'Multitool', some 'f-off' pump pliers, big 'F' adjustable's and possibly even a big std adjustable that will go up to 52mm at the ready. ;-)
Ok (The silicone grease was mentioned elsewhere).
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we do replace the valves, are these worth the extra would you say please (I'll check her pipework is actually 22m etc).
LOL. Sounds about right!
Understood. So I believe the pumps 'normally' come with washers. So say I bought a Grundfos from SF this morning, would it likely come with synth washers or would I have to buy those separately (from)?
Good they almost certainly will shut off properly. Were they easy to turn, with just a little bit of resistance? No damage in the slot in the picture so I guess they were, this is good sign.
Looking at the pic and what you have said I don't think you will need to replace the valves. Just get rubber/synthetic washers washers, the pump will probably come with fibre bung those in the bin. Not sure if Screwfix/Tolstation/the sheds carry them but a decent plumbers merchant ought to.
=A0Usually the screw slot in the valve stem is lined up with the hole/ port inside the valve. So you turn it so that it is =A0at 90deg to the pipe run to shut off.=A0And parallel with the pipe to open fully.
BTW. If a new pump becomes necessary, Check the face to face dimensions ie between the flange faces that they are the same. In days of yore there was some variations between pump manufacturers. Nowadays they seem to be standard.
Be sure to clean up the flange faces on the valves to a good standard without scoring/marking them.
When undoing the big nuts, try to avoid putting any strain on the pipework. ie get someone to hold the pump body against the torque.
What I actually did in the end is initially use two pairs of pump pliers in opposition on the big nuts (watching the pump carefully as I did so) till one 'gave', then I nipped it back up again. Then I held the other isolator valve across it's flats and undid the associated nut whilst the Mrs held the pump body still. The second nut was a bit harder than the first (as would be expected).
Then pump came out easily, complete with (fibre) washers.
I then dressed both valve surfaces with the fine file on my Leatherman, till they felt nice and smooth (it was a bit awkward as both valves were seeping quite a bit and couldn't be improved by tweaking their position).
I lightly silicon greased both pump threads, put the rubber washers in place and slipped the new pump in and nipped up the nuts.
(For your second reply)
"Oh and make sure you install any new pump in the same way round as the existing, ie pumping the water the same way."
Before I removed the old pump I noted it was pumping downwards. The flow came from the boiler below and up to above the pump where it T'd across through an air trap and then back down to the input of the pump. From there to the motorised valve, HW / CH.
It all fired up ok and soon after we were rewarded by a fried 'brunch' and a nice cup of tea (in the warm). ;-)
Thanks for your advice. ;-)
Cheers, T i m
p.s. Apparently the system hasn't been drained / re-inhibited for some time so maybe we could do that for her in the spring.
As it turned out ... the both 'shut off' but neither did so 'properly'. ;-)
Initially no, then eased up once 'worked' a bit.
Yup, turned with the Leatherman PST II big flat blade with the tool used like a ratchet brace. Once moved, they moved much easier.
Yup.
Luckily it seems the new Grundfos 15/50's come with (what looks like) rubber washers. The valves seeped sufficiently that we didn't want to leave the joint open to stop to eat. The upper one had half filled a plastic measuring jug in about 10 mins and the seep couldn't be lessened no mater how I tweaked the valve. Good enough to allow the job to be done without drain down though and it would be quicker next time with the siliconed greased threads and the rubber washers.
However (and a slightly sobering thought), there might not be a 'next time' for her and that pump. She reckons the Myson pump that was in there was the original from about 27 years ago (but she could well have forgotten).
As it happens the local merchant did me a good deal and the pump was cheaper than SF. My second big pump pliers (two pairs seem a good idea) were another 15 and he threw in a small tin of silicone grease. ;-)
She paid for the bits, we (the Mrs and I) did the job (it was handy to have a second pair of hands on the rags and inspection lamp etc).
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it had to go on upside down (but from the link you gave previously, and the supplied instructions, that was a valid (if not ideal) position).
I noticed the Myson pump was on flow level 1 so I put the new one on the same setting (for starters at least).
A couple of points might still need attention (in the spring)?
1) It might enjoy a flush and re-fill with new inhibitor.
2) She mentioned that although most of the rads were fitted with TRV's, 'they didn't work'?
I've never setup such things but assume that ignoring any overall balancing, each room rad stat valve should do it's own thing and limit the room upper temperature to something predictable? She also suggested this was the second lot they had tried?
Anyway, all the best and thanks to you and all for your help. It all helps give a bit more confidence on things you aren't doing very often (or in my case, ever before). ;-)
Excellent, I suspect you'll be going back to them for plumbing bits in the future rather than Screefix.
If it ain't broke, don't fix it! What colour was the water that seeped out? If there isn't a radiator that needs regular bleeding I wouldn't worry too much. A bit more inhibitor might not hurt.
I think you need to find out what is really meant by "they didn't work". They system still needs to be properly balanced with all the TRV's fully open, ie heads off. After that the TRV should keep the room more or less at the temperature set. But how well that is done depends a bit on the rest of the system and it's controls.
Glad to help and that it all went well. Good felling isn't it? "I did that".
The pump that failed on me and I had to remove as lump by cutting the pipes took about a day and half and a drain down. This was in top floor flat, the drain point was under a loose bit of flooring in the middle of the hall under the fitted carpet... Access to the pump and pipe work was cramped by being right up against the HW cylinder.
I don't use SF very much these days (Toolstation is closer and cheaper) and do use this particular local PM for many things, even if they are 'a bit more expensive' in some cases. It's just SF had the best price on the pump, till I phone my local place.
Hmmm, that sounds like my stepdaughter who will just turn the radio up in her car when she hears a new 'funny noise'. Then I have to fix it when it does eventually go bang. ;-(
Erm, I would say mostly clear with black bits / staining?
She's not said and I'm sure she would if one was not running properly. ;-)
Ok.
I think 'that they didn't manage the temperate of the individual rooms as hoped'?
OK. Well, I have no idea if the system was ever balanced or if it's still balanced now. I think she has either had a rad replaced or added as there is so new pipework in the hallway.
Yup, and one I'm pleased ('proud', as this is a d-i-y group) to say I have enjoyed since a kid. Being it building my first push go-cart, re-building my first bicycle after finding it in a ditch (and handing it to the Police), my first moped (bought off a teacher for £5 with a stripped plug thread) or my first car (Morris Minor Van bought for £25 and had to replace the gearbox in the carpark in the rain, at night to be able to drive it home). Also, re-plumbing, wiring and some fairly major building work (removing chimney breasts through to the stack) in this place.
However, it is even better when you can use your skills to help someone else, again, a feeling not unknown to me over 30 years in 'IT Support' and being the one much of the family turn to when they need some practical advice or something these things done. [1]
Yup, that was the fear for this job by the Mrs (we are *supposed* to be doing my Mums bathroom). As is often the case, it seemed to work out ok.
Ouch. I've fitted a drain point at Mums, in readyness for that time when it needs to be done in a hurry and they find no point exists (lower than the boiler [2]). It meant tapping (1/4" BSP) into one of the big brass T joints under the floor near the front door and using a
10 mm end (with nut / olive removed) - 15 mm compression converter to allow me to fit a std drain c*ck.
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didn't try soldering because the pipe was pretty large (1 1/4") and wasn't the absolute lowest point so I couldn't drain it right down.
Ah, I feel we were spoiled on this particular installation. ;-)
Cheers, T i m
[1] A good example of the 'doing something good' feeling was when a good mate phoned me in a panic one Sunday morning. Long - short, the back door had fallen off his mini Shogun 4x4 and he was due to go to the airport in it later that day. I took the hinges off one at a time (the hinge pins had sheared off though lack of lube), managed to get the hinge pins out of both sides and turn up / down some long socket head bolts to fit. He drove off happy a couple of hours later. It didn't dawn on me but as he was thanking me he said "I don't know who else I could have asked at such sort notice who would have actually been able to do such a neat job ... ". There are people out there of course (especially here), just that he didn't know any. ;-)
Luckily, we have each other (here) to turn to for help and advice. ;-)
[2] I think the original drain point was lost when the gas boiler was fitted.
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