Grundfos UPS 15-50 stripdown, clean and rebuild tutorial

[world_of_woodchip]

View a video tutorial showing how I renovated my circulating pump.

I couldn't find any service information or a how-to-do-it. so I made one!

Hope it helps you.

www.webmozaic.com/grundfos/index.htm

 

[Andygasman2010]

Nice work! I've never done this peronally as it's a bit too time consuming. It's certainly saved you a few quid though so can't argue with that. Lets hope you get at least few years out of it.

One pointer maybe to soak the pump body and impeller in vinegar or spirits of salts (HCL for a while, this will lift the black sludge off much easier. I do this when cleaning out heat exchangers and it works a treat.

Also, did I see a 13A fuse in your spur? It's most likely meant to be a 3A depending on your boiler.

Thanks

 

[Happyplumber]

We call this CLEANING THE CAN andtime served plumbers have been doing this for as long as i can remember,normally friday nite some old dear hasn't got any heating and you have used the last replacement grundfos in the van

Nowdays its alot easier just to change the body ,of course as professional we have to look at costs of labour compared to the price of goods,but an excellent tutorial for diyer

 

[world_of_woodchip]

Thanks for the comments guys.

@ Happy...We're on a bit of a budget so cleaning the can was the first option, if that didn't work, then scratch head (with clean finger) and splash out for a new one.

@Andygas...Well spotted with the fuse, (bet you went to Specsavers!) that has now been changed. Thank you

All the best
Drew

 

[Axel]

Nice documentary sequence, although:

PTFE tape on olives is a bit of a short cut - I would have cleaned or changed them to ensure a good seal.

Pump valves - I would have removed the pump from them and replaced washers if necessary, so that any future replacement or work on the pump could be done without draining.

Electrical junction box is safer if sited on a vertical surface where any leaking water will not 'pool'.

I am a critically minded person, however, so don't let me put you off!

 

[world_of_woodchip]

Hi Axel

Thanks for the complement.

What you may not be able to see is that in the original installation between pump and motorised valve, there wasn't any tape around the olive at either end and it has seeped so there may be an issue with sealing on that joint. PTFE is a bit of an insurance policy. Same deal with the MV outlet pipes

I couldn't change the olives without cutting the pipe as they'd been tightened up so that they crimped the pipe slightly - more work than I needed, for the sake of a few inches of tape.

I did actually remove the pump valves which I now realise wasn't shown and they were throughly cleaned out as they didn't close and seal due to boiler crust buildup in the gate seat. I replaced the washers with graphite washers (B&Q) and some flange sealant as the rubber washers had perished and now they're watertight. I also repacked the gate valve shaft gland with some pfte twirled as string as the o-ring had gone hard and also wasn't sealing particularly well. as witnessed by limescale buildup.

You're right about the J-box, it should be vertical but its been there for 25 years. I'm not sure the cables would reach the wall, I could change them, alternatively lift it onto a small block. Considering all the holes in the floor of the airing cupboard, I doubt water would pool there.

Anyway, many thanks for taking the time to reply.

A

 

[Paulbrill]

Thanks so much for this article.

I recently replaced my hot water cylinder and some pipework and ever since my Grundfos 15 - 50 pump has been making all kinds of noises, from rattling to whoooshing to humming noises.

I have bled the system several times and still it made noise, so it's not an airlock.

This morning i was going to go and buy a new pump, but then saw this article. I opened up my pump and it was full of crust just like yours was, i removed the crust and put it back together and now it works almost totally silently. Also the flow rate is much higher as it is much more efficient now cleaned and is pumping water rather than just swishing it about inside itself.

Thanks for the article, saved me 72 quid , nice one

 

[world_of_woodchip]

@Paulbrill You're welcome, really happy it helped.

Just as an update (12/12/11) . Ours is still working fine so good return on investment of labour.

 

[kirkgas]

one of the best things to clean a pump is household washing machine soap powder on a cloth, cleans the impeller like new and can pull tyou out a hole over a bank holiday weekend etc, have seen them last for ages

 

[Agile]

If the pump impeller is like that then I hate to think what the rest of the system is going to be like!

For my customers I would have to advise a proper system clean!

 

[world_of_woodchip]

@Kirkgas
I did that, really strong mix too, wouldn't touch it. This crust is really nasty!

@Agile, not so bad, various radiators and pipes have been off and not too bad. The exception to that rule was the double lounge rad - with no drain cock! Black cack ran out of it for ages.

I have run system flush through the system every two years or so and then popped some protector stuff in.

Fun fun fun!

Happy Christmas everyone