Grundfos MQ 3-45 installation

[brian62c]

Hi, I'm installing a new Grundfos MQ 3-45 water pressure booster pump and have got fittings to take the 15mm supply on to the 1" inlet port (and the other way round for the output). I need to fit the non-return valve (supplied) into the inlet port but the 1" female end of the fitting does not seem big enough to incorporate the valve. I not confident enough to try forcing it.
Any suggestions please? I got the fittings from a plumbers merchant but they just seem to my amateur eye to be standard plumbing fittings and maybe not necessarily ideal for connecting a pump like this. Are there specific fittings available?
I've tried emailing the pump suppliers but they were less than helpful now they've got my cash.
Cheers,

Brian

 

[doitall]

Would you explain what you are connecting it too, because 15mm is no good to man not beast, for a pump that size.

Do I have a feeling you are trying to connect it to the mains.

 

[brian62c]

The water comes into the house from a private borehole, hence the need for a pressure boost. It comes into the garden from the field in a large-ish (25mm?) black plastic pipe which then reduces to a 15mm copper pipe to come into the house and connect to the pump. The MQ 3-45 is a replacement for an old Jetpaq pump.

 

[doitall]

So you're installing it inline with the borehole pump Or does the borehole supply a high level reservoir.

What you need is a large storage tank somewhere, could be in an plant room or outbuilding, and pump it from there.

 

[brian62c]

The borehole supply is purely pressured by gravity - no pump involved. Without a pressure pump in the house, the supply around the house is only just adequate. Our fields are a fair bit higher than the house, which is a very old Welsh farm cottage. A storage tank is not an option, I'm afraid. I have had the new pump working quite happily without the non-return valve fitted but it won't shut off once demand stops unless the valve is there.

 

[doitall]

I still say the inlet supply need to be larger.

The non return valve can quite simply be cut into a short length of 28mm pipe, before the flexible hose

 

[brian62c]

Er, what flexible hose? The pump didn't come with any and it's not mentioned in the installation instructions. Also, the valve is about 36mm diameter at its widest point. It looks a bit like a car hot water thermostat (or, in my wife's opinion, a champagne bottle stopper!). It's a ring of black plastic with a three-armed frame attached to one side of it, in which a spring-loaded sort of spindle with a crossed end moves back and forth when you press it, within the ring of plastic. Hard to describe. It has POM 21801098 and a number 3 stamped into the plastic ring. The whole thing is about 50mm long.

 

[doitall]

Sorry, it has a hard connection, was thinking of another pump.

Can't see anything in the MI about the part you're talking about, where does it say it goes in the MI's.

a pic perhaps.

 

[brian62c]

Says it goes in at the input port but not sure exactly how. Will try and sort a pic.

 

[brian62c]

For input port read inlet port. I've uploaded a couple of pics to an album called MQ 3-45 valve but I this is them here:

View media item 22592
View media item 22593
In the booklet it says: "A non-return valve is supplied with the pump. It is recommended to fit this non-return valve in the pump suction port".
That's all it says. It doesn't tell you how to do it or what fittings to use. Not too helpful really.

In the fault finding chart, it says (under the fault 'Pump does not stop' - which is what mine is doing): "The non-return valve is blocked or missing".
I assume, therefore, I should have fitted the valve - I just don't know how!
And why, if fitting the valve is "recommended", does it cause a fault if it isn't fitted? Surely the booklet should say "essential", or am I being picky?

Ho hum....

 

[doitall]

I can't see how it can be call a non return valve or work, unless there's a seating for it to go against, therefore I would expect it to only fit one way.

 

[brian62c]

Ah well, I think it needs an email to Grundfos and hope one of their techs can enlighten me. Thanks for your replies anyway doitall.

 

[brian62c]

Well, don't know whether to feel elated or stupid. I went on the Grundfos website and delved into their servicing videos - and found this:

http://net.grundfos.com/Appl/WebCAPS/LiteratureDetail?documentid=20596&language=USA

For those of you who don't want to be bothered going there, it's a short video showing the simple task of fitting the non-return valve I've been angsting about. You just unscrew the black plastic bit (suction port) and drop the valve into it, then screw the whole thing back on. Takes about 10 seconds - BUT THEY DON'T TELL YOU IN THE MANUAL!!!
I needed to know I was supposed to unscrew it. It was on pretty tight and I didn't want to force it.
Anyway, hopefully all's well that ends well.

 

[doitall]

Did you catch which way it went in

 

[brian62c]

Yep, used the pause button on the video to good efect and the pointy end goes into the pump. The chap on the video actually dropped the other end (shaped like a cross if you look at it end-on) into the plastic screw-on bit from the pump, then fitted that to the pump and screwed the whole thing on. Easy peasy.
In case of confusion, if you visualise the valve as a space rocket, it goes in nose cone first

B.