Low voltage transformer for shower pump.

[NowWhyisThat?]

Hello. Can anyone advise on this? I have a low voltage transformer which powers my shower pump. Can these things develop faults over time? And if so, how do those faults present themselves? I turned on my shower yesterday and nothing happened. No water at all came out of the shower head apart from a very small dribble. Immediately thought that the pump had gone. However, a few hours later I tried turning on the shower again and this time it worked. Could it be a faulty transformer? Or a faulty pump? Normally when I switch off the transformer at the mains outlet and then turn on the shower I get a steady but very light flow of water from the shower head ( ie: a non-power shower). When this fault occurred there was virtually no water at all from the shower head. Also, for the past 6 months or so I can hear the pump noise intermittently “dipping” and then “recovering” again, almost as if the power is about to cut out but doesn’t quite get to that point. Any expert thoughts would be appreciated. It would be a shame to change the pump if there is nothing wrong with it, and the fault is with the transformer.

 

[terryplumb]

Is the pump an SP1 ?

 

[NowWhyisThat?]

Don’t know what that means. Sorry. It is a Grundfos Danube STL 1.5C.

 

[NowWhyisThat?]

That is - it is a positive head pump.

 

[terryplumb]

It's just one brand of pump. The fact that no water comes out of the shower head when pump is electrically Isolated, may be indicative of a plumbing problem ,rather than a pump / transformer issue. Does your pump start automatically when shower is turned on ?

 

[NowWhyisThat?]

Yes Terry. It does.

 

[NowWhyisThat?]

When you say it could be a plumbing problem what do you mean by that? Last time the pump needed replacing it just died mid-shower but the water continued to pour from the shower head but without the power of the pump behind it. On this current occasion the water just stopped from the shower head almost completely, apart from a very small dribble. That’s why I am wondering if the transformer is at fault, rather than the pump, given that the pump is now working again And everything appears normal again, apart from an audible intermittent “dip” in the noise level of the pump while it is doing its business.

 

[terryplumb]

From what you have told us ,sounds like there is sometimes insufficient flow of water to trigger the pump ,so it doesnt start up. When it does ,and is making the different sounds that you describe , it could be "hunting" . When it makes theses sounds does the water from shower head ,splutter / drop and increase in flow ?
I would suggest you look at all filters for cleanliness and any non return valves to ensure they are not sticking.
In my experience electronic transformers either work or fail totally.

 

[NowWhyisThat?]

Thanks for your advice Terryplumb. Much appreciated.

 

[Alec_t]

If on a previous occasion without the pump running the water continued to flow at a steady non-pumped rate, then flow reduced to just a dribble would suggest there's a piumbing problem: not a transformer problem.

 

[NowWhyisThat?]

Thank you Alec. Much appreciated.