Replaced Electric Shower engine - now no water flowing?

[parkaboy]

Hi all

I have a Gainsborough 9.5 SDL electric shower that started running cold this week so I ordered up a replacement inside (it all comes as one unit) and installed it today.

I switched the stopcock off while replacing the unit, wired it up, replaced the cover then switched the stopcock back on but no flow from the shower.
The taps are running in the same room no problem but nothing from the shower.

I've checked the hose and filter for obstructions and all look clear.

I live on the 2nd floor of a house so have checked the attic to see if the shower is mains or tank fed; I can't follow the piping under the boards but the tank is full anyway.

Tried running the shower for 30sec to see if can draw airlock out but no joy.

Anybody got any ideas?

Cheers

Niall

 

[muggles]

Is the motor running? I take it from your post that it probably is. Partially undo the nut connecting the shower to the water supply with the water switched on and see if there's water there, it might just be that the pipework needs bleeding of air

 

[parkaboy]

cheers muggles

The unit has two inlets so I've been able to pull the plug in the spare one and see through the filter...very slow drip. When I track the pipe into the attic can't see if it terminates at the tank but presume it must, 2nd floor flat.

Was thinking about splitting the pipe in the attic (with a bucket handy!) and seeing if I can bled it from up there, there is a tap on the pipe.

Do you think this makes sense?

 

[muggles]

You said originally you turned off the stopcock to change the shower. Unless you drained your entire loft tank to change it I suspect it's on mains.

If you want to break into the pipe, turn off the valve that you say is on it and undo the compression nut rather than cutting the pipe - it'll be much easier to handle.

Are you sure you removed the inlet plug from the inlet connection you've actually used? Might be worth checking.

Oh, and here's the instructions... http://www.gainsboroughshowers.co.uk/upload/Documents/Gainsborough_Electric_Shower_07.pdf

 

[ColJack]

ok, idiot questions time..

you did turn the power off at the CU while replacing the insides didn't you?

you turned it back on again afterwards and the ceiling switch too?

you checked that the RCD for the shower hasn't tripped?

you checked for voltage at the shower terminals?

 

[parkaboy]

@muggles and coljack

thanks for taking an interest, the missus is none to pleased about the lack of shower but at least she has started going to the gym again.

muggles:

D'oh...that really is an obvious one I should have spotted, laughing at myself now.

Coljack:
Thanks for the idiot list but rest assured, i don't fancy frying myself! I'm no electrician but anyone daft enough to work on a live electrical connection in a bathroom are probably just polluting the gene pool and will spawn generations of idiots.

No problem with electrics. The mains feed splits in the attic with a pipe running to the shower. When installing I closed the main stop cock into the property but I should have just closed the pipe to the shower. The vertical section of the mains feed from the attic to the shower is now airlocked because it drained while I replaced the unit. I can get low flow to the shower by restricting the flow in the feed using the stopcock in the attic but when I open it fully flow stops.

Any suggestions on clearing the airlock?

 

[muggles]

OK having now seen a diagram of the shower I can see it's impractical to try to undo the connection to release the air as it's a push-fit type. Have a look around the shower engine; some showers have a commissioning button that you can press to let the air out and the water in, and on some you can manually operate the pressure relief device which will achieve the same end result of getting water to your shower. Just make sure you do this with the power off to avoid mixing electric and water

 

[parkaboy]

cheers muggles

I'm still not entirely convinced that it is an airlock in a mains fed pipe but it's the only explanation I can come up with.

If you have the diagram check out the two inlets. I've got a vertically straight pipe from the attic into the top inlet so when I pull the plug from the bottom inlet the is a clear path for the water to flow so it's not air in the shower unit creating a blockage.

When I choke the flow in the pipe using the stopcock in the attic the water starts to flow running straight out the downward facing inlet. As I open the stopcock further it reaches a point where it stops flowing and it feels like air in the pipe: the operation of the ball valve in the stopcock becomes *spongy* and there is a short bump noise...hard to describe!

We live on top of a hill so water pressure is not great so I think it is flowing into the attic but does not have sufficient head to displace the air is the pipe where it drops 90' down to the shower.

I was thinking about trying to suck the water down, just have to rig something together...

I work as an drilling engineer but I'm defo no wizard when it comes to plumbing!

 

[muggles]

Hmmm OK this opens another possibility; the problem could in fact be the stopcock you're turning. If the washer / general insides have come loose then that'll restrict the flow. Try replacing it, I'd suggest using a quarter turn lever valve as the replacement; no washer to replace and you can generate full flow quickly which might help.

 

[parkaboy]

I see where you going but the lack of flow existed before I started turning the stopcock, unless the washer/general insides came loose in the pipe when it drained (after I switched off main stopcock)...maybe the pressure of the water was holding it in place? I'm not familiar with the internals, is that plausible?

Cheers for taking an interest...it's always good to get some advice from someone who knows more than me (not hard!)

 

[parkaboy]

Thanks for advice muggles, got the water flowing again and shower is working nice and hot.

Made a little suction pump from a couple of plastic bottles and some tubing, couple of squeezes, pipe gave a massive burp and water came out full volume...really chuffed didn't have to start replacing stuff.

Another win for DIYnot

Cheers

ParkaBoy