Shower pump not activating on cold flow

[lylbf]

Afternoon all,

Would be grateful for advice on the following please. Forgive any sloppy terminology but I'm not an expert...

I have a shower pump (Salamander CT55, I think) that feeds the mixer bath taps and mixer shower. Cold water comes from storage tank in loft, hot water from cylinder. A few days ago the pump stopped boosting the cold flow to both bath and shower: the hot flow activates the pump as normal. It seemed to correct itself yesterday (although the cold flow was not as strong as the hot flow, and not as strong as usual). This morning, same problem recurred, no cold flow.

There is no loss in flow to toilet or basin in the bathroom, although these are not fed by the pump.

The pump and associated pipework is not accessible without removing a tiled bath panel, so I haven't been able to examine more closely (although what I'd be able to do I'm not sure).

Is it likely this is a problem with the pump itself, or a blockage on the cold pipework feeding the pump? I don't understand how the toilet and basin are unaffected if it is a pipe blockage, as they draw their cold water from the loft tank; on the other hand, I don't know whether it's possible for a pump to fail on cold flow only. It seems to me that a lack of flow to the pump is the likely issue, but would welcome any thoughts.

 

[longdogs]

The first thing to check (if you can get to it) is the filter on the cold sde of the pump. Sounds like it may be blocked.

 

[lylbf]

Thanks Squeaky. Problem seems to have resolved itself as pressure back to normal, could blockage have cleared or is that wishful thinking? Will monitor...

 

[SimonH2]

Can you clarify, if you turn on the cold tap on the bath (which from the way you describe it should be running from the pump), does :

a) The pump run but you don't get the normal flow rate

b) The pump doesn't run

If it's the latter, then it sounds like one of the flow switches is failing. There will be two, one on the hot, one on the cold - so the pump will run if either side is flowing. It sounds like the one on the cold side is either sticking, or the switch is failing.
If it is the switch, then turning on the hot tap a little should fire up the pump and you'll get the normal flow rate from the cold tap.

 

[lylbf]

Unhelpfully, it was a mixture of a) and b). For a day or so the pump did not flow at all when the cold tap on the bath was opened. Then there was a period where if you did the same, the pump would run intermittently. Now it is running fully on when cold switched on.

Opening the hot tap first, then the cold, didn't seem to get the cold flowing, but maybe whatever it did 'unstick' the switch after a while.

 

[Agile]

You may have a "mobile blockage" in the cold supply to the pump!

They can be difficult to find.

A common and annoying one is a plastic disc cut from a plastic tank that he been dropped into the tank. The move to allow a reverse flow and flap down the prevent or restrict the flow! Can require all the pipework to be removed to find it.

Tony

 

[lylbf]

Thanks everyone for your replies. Problem with the cold flow is back now Salamander are pointing to a problem with the cold flow to the pump rather than the pump itself, which does seems sensible. Guess I'll have to have the filter pipes cleaned and hope that does the trick. If there's something in the down pipe from the cold tank, can that be easily cleaned out or would the whole assembly need to come out?

Also sounds as if I have the wrong pump for boosting pressure to both taps and shower: one I have is apparently for shower only and I should replace it with a whole house pump! Any thoughts?