Shower pump stopping/starting, poor pressure

[Johnny2R]

I have a Stuart Turner ShowerMate twin shower pump which has suddenly stopped working properly. It stops and starts and even when it's running the pressure is low. Because this happened a few days after I replaced a ball valve in the header tank in the loft, a process during which some debris including a clump of glass fibre loft insulation fell into the tank, my conjecture is that the problem may well be caused by a blockage of the cold water inlet to the pump.

Does this sound plausible? In theory it should be easy enough to check out, as I believe there is a mesh filter which I could clean. The problem is that, as far as I can tell, the pipe from the header tank goes straight to the pump without any kind of stop valve. This presumably means that I would have to turn of the water at the mains and completely drain the header tank to do this work. Is this normal?

I would stress than I'm an absolute noob with this stuff, and may well have missed something obvious, such as pipe connectors which can be twisted to stop the flow or something. Just seems odd that someone would plumb this in without putting a valve in to stop the flow.

I have a feeling that we had the pump replaced a few years ago, so it's not mega-old (although I don't know what the lifespan of these things is).

 

[dpsservices]

Post a pic of pump and pipe leading to it. Every time I fit one I always use a full bore leaver isolator. Makes sense mesh could be partly blocked or maybe air in pump. Turn pump off and turn shower on and place handheld shower attachment on floor. Run for a minute and then turn pump on while someone holds the shower attachment on the floor incase it's starts going everywhere
Regards david

 

[Johnny2R]

 

[Johnny2R]

Sorry, one of the images is duplicated there. The one showing the pipe coming off horizontally is where the pipe to the shower pump branches off the main pipe from the header tank. The other two are joins further down (including another pipe going off somewhere else, not sure where), and the pump itself. The nearer pipe on the right of the pump is the one from the header tank.

I tried the technique for sorting out an air block yesterday and it didn't do anything. Just tried again now, leaving it for a minute following your suggestion, and still no joy.

Thanks for your help!

 

[terryplumb]

I assume the loft tank also supplies a hot water cylinder ,so you may well have contaminated the hot and or cold . no isolation valves on your pics ,unless they are within the final connections to the pump and not showing on pics.in their absence you can fit " bungs" into the water outlets at bottom of loft tank ,but a safer way is to drain out. I would also check the filters at your shower valve inlet ports .

 

[dpsservices]

Best best isolate mains drain down and check filter on pump, have a bucket handy to put pipe in once undone to take water out of pipe
Regards david

 

[dpsservices]

Also once pipe off try blowing up pipe to check it's clear
Regards david z

 

[dpsservices]

I assume the loft tank also supplies a hot water cylinder ,so you may well have contaminated the hot and or cold . no isolation valves on your pics ,unless they are within the final connections to the pump and not showing on pics.in their absence you can fit " bungs" into the water outlets at bottom of loft tank ,but a safer way is to drain out. I would also check the filters at your shower valve inlet ports .

Or as terry says just seen your post bud
Regards david

 

[terryplumb]

 

[Johnny2R]

I assume the loft tank also supplies a hot water cylinder ,so you may well have contaminated the hot and or cold

What would happen to a bit of loft insulation going down the pipe from the loft tank to the hot water cylinder? Is there likely to be a filter on the inlet to the cylinder? (And what function does that feed have, incidentally, as I would have assumed that the hot water cylinder would only be filled with hot water from the boiler, not cold water from the loft?)

 

[firebladerrw]

Coincidentally, I have the same make of pump, although its a ST Showerforce twin impeller one. I've been experiencing slow start ups, and on occasions, it sometimes takes 30 seconds to kick in. Its 5 years old, and assumed it may be the flow switch packing up, however if there is a filter, it may just be blocked, or perhaps the pipe has a blockage, enough to slow down the flow less that the 0.9 L/min required to start the pump.

Are the filters on the incoming pipes or inside the pump itself?

 

[firebladerrw]

ps: Just spoke with Showerforce, and they reckon an airlock in the pump causes these symptoms. They recommend:

1. Isolate the pump electrically
2. Remove the shower head, and ideally attach a hose to get more flow
3. run the hot water for a good few minutes, then run the cold water for a few minutes

They reckon this may force out any air bubbles locked in the pump.

Sorry to hijack this thread, but it may help.

I'll be trying this tonight after work.

 

[Hugh Jaleak]

What would happen to a bit of loft insulation going down the pipe from the loft tank to the hot water cylinder? Is there likely to be a filter on the inlet to the cylinder? (And what function does that feed have, incidentally, as I would have assumed that the hot water cylinder would only be filled with hot water from the boiler, not cold water from the loft?)

The majority of modern systems have what is known as an 'indirect' hot water cylinder. Basically the water within is heated indirectly from the boiler. You have 2 circuits, Primary, which is the boiler and central heating system. This contains its own water, which is continuously circulated, and to heat the hot water, passes through a coil of pipework within the cylinder, transferring its heat to the water within the cylinder.

The Secondary system is the water stored in your cold water cistern in the loft. This supplies the hot water cylinder and thus the hot taps. Highly unlikely to be any type of filter on the inlet to the cylinder, any insulation that found its way into the cylinder has the potential to travel along the outlet from the cylinder to any of the hot outlets in the property.

If the shower pump has always been slow to start, its worth checking it has been plumbed in properly. Failure to take the supplies from the right points in the system can allow the supply pipework to airlock, or the pump draw in air, muck or both, possibly leading to cavitation, and/or premature pump failure.

 

[Johnny2R]

Thanks for the explanation, makes sense now. No, the shower pump has worked absolutely fine until a few days ago when the problem suddenly appeared.

As regards draining the loft tank, it appears to me that I have to run off all the hot water, which I would be sad to do as it's rather wasteful. I looked at a diagram of a typical indirect hot water system on the web and it showed cold taps in the house being supplied from the loft tank, only the main one in the kitchen coming from the mains. That's not the way it is here, though, as all the cold water in the bathroom (bath tap, washbasin tap, toilet flush) clearly comes from the mains, so I can't simply empty the tank using cold taps or the like. Is there something I can do which doesn't involve wasting all that hot water?

 

[Johnny2R]

Incidentally, the pipe going to the shower from the pump (the cold, I presume) does in fact have an isolation valve on it. This doesn't make much sense to me and it makes me wonder whether whoever fitted the pump originally simply put the isolation valve on the wrong pipe by mistake.