Leak around hot water pump due to old limescale

[Spanky2k]

Hey guys,

The floor in our cellar has been flooded lately (well, a big puddle that I keep having to mop up) and I'm pretty sure I’ve narrowed it down to a hot water pump, which is dripping. I installed a water softener about six months ago and I think what’s happened is that this old pump had a leak for years that ‘self sealed’ with limescale which is now being broken down with the soft water. When I first looked at it last week, I could chip off chunks of what I think were limescale. The pump itself still seems to work fine so I think my best bet for now is just tightening it all up and/or cleaning up the connectors. I've ordered a pump spanner as none of my existing ones were large enough.

The question I have is, do these pumps have rubber washers in them? In which case, what size would they be? The pump is in a really awkward position so I don't really want to have to take it apart twice so if there are rubber washers that will have failed by now, I'd rather have replacement ones ready to put in. I think the leak is coming from the lower 52mm pump connector or the 22mm pipe connector below it - both seem to be wet. The connectors above the pump seem to be dry.

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• Spanky2k
• 2 Nov 2019

 

[Madrab]

If it's leaking around the pump valve nuts then yes, you can get replacement washers/seals. You will need to see if the valves will close first and that the nuts will loosen, with all that limescale then you may have a problem with that. Use a liquid designed to dissolve limescale. Make sure the valve and pump faces are super clean and don't overtighten the nuts

Just search for pump valve rubber washers/seals - usually 1 1/2"

 

[Spanky2k]

I got some new seals but I quickly discovered that there was no way I was going to be able to get the pump connectors open and cleaned in situ so I ended up just buying a new pump and new pump connectors. The amount of limescale on this old thing is really quite impressive, so see a few photos attached. This is after a fair chunk of limescale remover and after having chipped off a good chunk of the stuff.

IMG_2309

• Spanky2k
• 7 Nov 2019

IMG_2311

• Spanky2k
• 7 Nov 2019

New pump in and no more leaks:

IMG_2315

• Spanky2k
• 7 Nov 2019

 

[ianmcd]

Well here is the bad news, you will have to take that pump back out as it is for CH systems, the old pump is bronze pump for fresh water systems, the new one wont last long it is not designed for that use

 

[HERTS P&D]

The worse part of this is the socks!!!

Andy

 

[Nige F]

Well here is the bad news, you will have to take that pump back out as it is for CH systems, the old pump is bronze pump for fresh water systems, the new one wont last long it is not designed for that use

The thing is - as it corrodes internally you'll get rusty water through the taps Best to remove the incorrect C/H one soon and keep or ebay it . The limescale on the original one won't hurt it and the new valves you fitted will be fine

 

[Spanky2k]

Well here is the bad news, you will have to take that pump back out as it is for CH systems, the old pump is bronze pump for fresh water systems, the new one wont last long it is not designed for that use

The thing is - as it corrodes internally you'll get rusty water through the taps Best to remove the incorrect C/H one soon and keep or ebay it . The limescale on the original one won't hurt it and the new valves you fitted will be fine

Until I saw your messages, I had no idea there were different kinds of pumps. I just looked up what was a good replacement for a Grundfos UPS 15-50 pump and I came up with the Grundfos UPS3 I installed. I had no idea Bronze meant materials used. Thought it was a model term only. Anyway, new pump in again now. Replacing a pump is a piece of **** if the valves either side of it work! Replacing this pump took five minutes. Replacing the first one took a few hours as I had to drain *everything*.

The UPS3 will sit in a box for the time being. I plan on installing underfloor heating in our loft conversion when we reconfigure it at some point so it’ll come in handy then.

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• Spanky2k
• 10 Nov 2019

Now I just need to work out why we get scalding hot water out of the cold taps in the house for about a minute before it goes cold. Pretty sure it’s the old mixer in the loft conversion bathroom but there’s no way to isolate it. Another project for another day!