Hi all,

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?

http://preview.tinyurl.com/bugqeu4

Obviously 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 cock 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?

Cheers, T i m

On 17/12/12 20:11, T i m wrote:
Hi all,

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?

http://preview.tinyurl.com/bugqeu4

Obviously 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 cock 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?

Cheers, T i m

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.

Andy C

On Mon, 17 Dec 2012 20:27:23 +0000, Andy Cap
wrote:


I don't know enough to recommend a make, though personally I'd always
pay a bit more a good make

It seems (from my quick Google) to be a jump from ~40 to ~100 quid
though?

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.

Oooerr. I think I read somewhere that the shaft *should* be
horizontal?

As it happens the one I'm looking to change certainly is and it could
be the original, as is Mums (Grundfos)?

https://dl.dropbox.com/u/5772409/Myson%20Unit%203a.png

Cheers, T i m

On 17/12/12 20:58, T i m wrote:


Oooerr. I think I read somewhere that the shaft *should* be
horizontal?


Well it's worked for me ! ;-)

On Mon, 17 Dec 2012 21:06:48 +0000, Andy Cap
wrote:

On 17/12/12 20:58, T i m wrote:


Oooerr. I think I read somewhere that the shaft *should* be
horizontal?


Well it's worked for me ! ;-)


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 ... ;-(

Cheers, T i m

On Mon, 17 Dec 2012 20:58:10 +0000, T i m wrote:

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.

Oooerr. I think I read somewhere that the shaft *should* be
horizontal?

IIRC what they don't like is the "dry" end down in any shape or form.

The Brochure .pdf link on he

http://www.plumbnation.co.uk/site/gr...ric-130-bare-p
ump/

Contains 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.

--
Cheers
Dave.

On Dec 17, 8:11*pm, T i m wrote:
Hi all,

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?

http://preview.tinyurl.com/bugqeu4

Obviously 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 cock 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?

Cheers, T i m

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.

On Mon, 17 Dec 2012 20:11:33 +0000, T i m wrote:

As an aside, I've been able to turn the isolation valves (good old
Leatherman PST II) and I've located a drain cock if it comes to it.

If the isolators do turn, ...

Make your mind up...

... might they not still isolate and if so is it general practice to
change them at the same time?

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...

--
Cheers
Dave.

On Mon, 17 Dec 2012 23:59:40 -0800 (PST), harry
wrote:


If money is a problem
It may only have some crap in it.

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.

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)

Oh, ok. I might do that first.

You will need some form of jollop on the joint when you put it back.

Understood.

The bearings BTW are water lubricated.

Ah (makes sense).

The isolating valve(s) might well pass a bit but not usually enough to
stop you doing the work.

Ok.

They would only need changing if they leak from the valve spindle
after you have finished the job.

Right, well as I was working them round they did weep a bit but seemed
to stop once I stopped turning them?

This doesn't happen often.They are
quarter turn to operate.

Understood, although they can be turned right round can't they (I
think these did)?

Depending on the pipework layout, you might get some air in the sytem
& have to bleed a radiator or two.

Understood.

Thanks for the tips. ;-)

Cheers, T i m

On Tue, 18 Dec 2012 08:56:45 +0000 (GMT), "Dave Liquorice"
wrote:

On Mon, 17 Dec 2012 20:11:33 +0000, T i m wrote:

As an aside, I've been able to turn the isolation valves (good old
Leatherman PST II) and I've located a drain cock if it comes to it.

If the isolators do turn, ...

Make your mind up...

Yeah, sorry, I should have said 'as'. ;-)

... might they not still isolate and if so is it general practice to
change them at the same time?

Are they gate valves or ball valves?

Ball.

I'd almost put money on gate valves
either not turning and/or not shutting off enough.

Understood.

I also expect that the orginal insaller used fibre washers between the
pump body an valves as well.

Ok.

Can you see signs of that (rust on the body under the top nut) in this
pic?

https://dl.dropbox.com/u/5772409/Myson%20Unit%203a.png

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.

;-(

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. ;-)

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.

Ok (The silicone grease was mentioned elsewhere).

http://www.screwfix.com/p/pegler-pump-valve-22mm/20850

If we do replace the valves, are these worth the extra would you say
please (I'll check her pipework is actually 22m etc).

This will ensure that you never have to replace the pump again.

LOL. Sounds about right!

Use gate valves and fibre washers and it'll fail within 2 years and the
gate valves will have siezed/not seal, again...

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)?

http://www.screwfix.com/p/grundfos-u...ing-pump/50183

Cheers, T i m

On Tue, 18 Dec 2012 10:40:51 +0000, T i m wrote:

Are they gate valves or ball valves?

Ball.

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.

Can you see signs of that (rust on the body under the top nut) in this
pic?

https://dl.dropbox.com/u/5772409/Myson%20Unit%203a.png

Doesn't look to bad for rust. Might be a bit stiff to start.

If we do replace the valves, are these worth the extra would you say
please (I'll check her pipework is actually 22m etc).

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.

--
Cheers
Dave.

On Dec 18, 10:23*am, T i m wrote:
On Mon, 17 Dec 2012 23:59:40 -0800 (PST), harry

wrote:
If money is a problem
It may only have some crap in it.

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.

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)

Oh, ok. I might do that first.

You will need some form of jollop on the joint when you put it back.

Understood.

The bearings BTW are water lubricated.

Ah (makes sense).



The isolating valve(s) might well pass a bit but not usually enough to
stop you doing the work.

Ok.

They would only need changing if they leak from the valve spindle
after you have finished the job.

Right, well as I was working them round they did weep a bit but seemed
to *stop once I stopped turning them?

This doesn't happen often.They are
quarter turn *to operate.

Understood, although they can be turned right round can't they (I
think these did)?




Depending on the pipework layout, you might get some air in the sytem
& have to bleed a radiator or two.

Understood.

Thanks for the tips. ;-)

Cheers, T i m
*Usually 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 *at 90deg to the
pipe run to shut off.*And 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.

Oh and make sure you install any new pump in the same way round as the
existing, ie pumping the water the same way.

On Tue, 18 Dec 2012 08:48:51 -0800 (PST), harry
wrote:

*Usually 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 *at 90deg to the
pipe run to shut off.*And parallel with the pipe to open fully.

Understood.

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.

Ok.

Nowadays they seem to be standard.

Good news.

Be sure to clean up the flange faces on the valves to a good standard
without scoring/marking them.

I did ...


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.

On Tue, 18 Dec 2012 12:02:49 +0000 (GMT), "Dave Liquorice"
wrote:

On Tue, 18 Dec 2012 10:40:51 +0000, T i m wrote:

Are they gate valves or ball valves?

Ball.

Good they almost certainly will shut off properly.

As it turned out ... the both 'shut off' but neither did so
'properly'. ;-)

Were they easy to
turn, with just a little bit of resistance?

Initially no, then eased up once 'worked' a bit.

No damage in the slot in the
picture so I guess they were, this is good sign.

Yup, turned with the Leatherman PST II big flat blade with the tool
used like a ratchet brace. Once moved, they moved much easier.

Can you see signs of that (rust on the body under the top nut) in this
pic?

https://dl.dropbox.com/u/5772409/Myson%20Unit%203a.png

Doesn't look to bad for rust. Might be a bit stiff to start.

Yup.

If we do replace the valves, are these worth the extra would you say
please (I'll check her pipework is actually 22m etc).

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.

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).

Not sure if
Screwfix/Tolstation/the sheds carry them but a decent plumbers merchant
ought to.

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).

https://dl.dropbox.com/u/5772409/New%20pump.png

Shame 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). ;-)

T i m

On Tue, 18 Dec 2012 18:17:49 +0000, T i m wrote:

As it turned out ... the both 'shut off' but neither did so
'properly'. ;-)

Half a jug in what was it? 10 mins, is nothing...

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.
;-)

Excellent, I suspect you'll be going back to them for plumbing bits in
the future rather than Screefix.

A couple of points might still need attention (in the spring)?

1) It might enjoy a flush and re-fill with new inhibitor.

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.

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?

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.

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). ;-)

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.

--
Cheers
Dave.

On Tue, 18 Dec 2012 08:56:45 +0000, Dave Liquorice wrote:

When refitting use ball valves (assuming that the ones there don't
work)

a) ball valves are generally shorter than gate valves so you may have
trouble persuading the pipework to meet up

b) after a short while in service they leak when you turn them and then
won't stop leaking, IME

I now use Pegler pump valves. Haven't been using enough of them long
enough to say if they're definitely good for the long run, though.



--
John Stumbles -- http://yaph.co.uk

There's nowt as queer as folk.
Especially other folk.

On Tue, 18 Dec 2012 23:52:15 +0000 (GMT), "Dave Liquorice"
wrote:

On Tue, 18 Dec 2012 18:17:49 +0000, T i m wrote:

As it turned out ... the both 'shut off' but neither did so
'properly'. ;-)

Half a jug in what was it? 10 mins, is nothing...

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.
;-)

Excellent, I suspect you'll be going back to them for plumbing bits in
the future rather than Screefix.

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.

A couple of points might still need attention (in the spring)?

1) It might enjoy a flush and re-fill with new inhibitor.

If it ain't broke, don't fix it!

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. ;-(

What colour was the water that seeped
out?

Erm, I would say mostly clear with black bits / staining?

If there isn't a radiator that needs regular bleeding I wouldn't
worry too much.

She's not said and I'm sure she would if one was not running properly.
;-)

A bit more inhibitor might not hurt.

Ok.

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?

I think you need to find out what is really meant by "they didn't work".

I think 'that they didn't manage the temperate of the individual rooms
as hoped'?

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.

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.

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). ;-)

Glad to help and that it all went well. Good felling isn't it? "I did
that".

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]

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.

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.

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...

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 cock.

https://dl.dropbox.com/u/5772409/Drain%20point.png

I 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.

Access to the pump and pipe work was
cramped by being right up against the HW cylinder.

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.