# Your annual Duetto health check - Rotary Pump



## DavecUK (Aug 6, 2013)

You need to be checking your Duetto pump on an annual basis, now I am sure you all do that, but just in case.

The Duetto pump is mounted on top of the remarkably expensive RPM motor, should the pump leak, it will soak into the motor and damage the bearings. it is not uncommon for leaks to go unnoticed for many years. The rotary pumps have a shaft seal which eventually leaks, this is both on a usage basis (unlikely to happen for a LONG time in a domestic environment), but also on a time expiry basis. Usually the seals time expire and leak rather than leak through the level of usage in the domestic environment.

This makes an annual pump check a wise move and can save you from more serious and expensive problems. Simply loosen the pump clamp and lift the pump just enough to move it over slightly as shown. Use a torch to check for any leaks. Don't run the motor like this and the "key" may come off with the pump or it may stay in the motor spindle as shown. When re-tightening the pump clamp, enough so it doesn't twist, but not using the strength of Thor.









If you do notice water in there, then it's time to replace your rotary pump I'm afraid.

There is some stuff you can do to protect your motor in between annual check and also get an advance warning of pump leaks. I will post that article on the coffeetime Wiki, or here when I get more time. However, if you have not done this simple check, it should be on your list of things to do in the next few weeks.

P.S. Don't try and move the pump too far, because all the pipes are still attached, but there is enough flex to do what you see in the picture.


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## MarkB (Dec 18, 2013)

Thanks for this post Dave. I have now completed the inspection and all is well after the first year of usage. Just a couple of points for anyone else attempting this fairly simple procedure. Dave did not mention just what a pita it can be for the inexperienced like me to realign the 'key' which connects the motor to the pump. A bit of patience and it was done but I guess this could trip up some.

The other point is that on my machine there is a thin drain pipe leading from the flange at the top of the motor where it joins the pump above. I guess this is to drain any water that does leak out of the pump and provide a visual indication that the shaft seal has failed, although I can see this could be missed if you didn't know about it and what it meant.


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## DavecUK (Aug 6, 2013)

MarkB said:


> Thanks for this post Dave. I have now completed the inspection and all is well after the first year of usage. Just a couple of points for anyone else attempting this fairly simple procedure. Dave did not mention just what a pita it can be for the inexperienced like me to realign the 'key' which connects the motor to the pump. A bit of patience and it was done but I guess this could trip up some.
> 
> The other point is that on my machine there is a thin drain pipe leading from the flange at the top of the motor where it joins the pump above. I guess this is to drain any water that does leak out of the pump and provide a visual indication that the shaft seal has failed, although I can see this could be missed if you didn't know about it and what it meant.


I forgot the drain tube...but don't be fooled, that drain tube is about as useful as an Igloo in the Sahara. There is an early warning system you can make and a way to try and protect the pumps brearings if the worst happens, but I justy don't have time to write the article now. Quick guide... below

Dow corning molycote 111 to stop leaks to pump....thin wick through hole, water soluble marker, thin line on wick, water held in chamber by molycote, wick gets wet, line blurrs....enough to figure it out. been fitted to my machine for years.

Oh the key, yeah, if you move the motor at all....and it does move real easy! small PITA to realign.


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