Plumbing Help....
Hellfire - 31/10/11 at 11:04 AM
I'm after some expert help to get my shower working again 
The installation is as the diagram below. When I first installed it (over a year ago) it had an intermittent fault and the shower sometimes
wouldn't work unless the pipes feeding the shower pump were tapped. Sometimes this wouldn't work at all but if the thermostat control was
tapped, the shower would start up. At first, I suspected that air was causing the problem as the shower pump feed from the top of the tank isn't
horizontal and points slightly upwards as it exits. However, I'm not so sure now that this is causing the problem as the shower no longer works
at all, no matter how much the pipes or thermostat are tapped.
I know that the vent pipe isn't drawing air into the system as I've checked it by sealing a polythene bag over the end whilst the shower was
running and it didn't suck the air out.
I suspect it's either the pump or a sticking thermostatic valve thats causing the problem but either of these will cost a few hundred pounds to
replace and are out of warranty. How can I determine where the fault is? I guess I could eliminate the pump to see if the valve is working but even
then, I doubt I'd get much flow due to lack of pressure and it would be a nightmare to connect the pipework up without the pump.....
Any plumbers in the house?............
Phil
Shower Plumbing
tegwin - 31/10/11 at 11:16 AM
What do you mean by "the shower does not work"... As in NO water comes out.... or, the water dribbles out and the pump does not start?
Shower pumps are very unstable if you have any air getting into the pipework... is it possible you have a tiny leak somewhere allowing air to form
around the switches in the pump?
jossey - 31/10/11 at 11:48 AM
sounds like a sticky valve.
Hellfire - 31/10/11 at 12:34 PM
quote:
Originally posted by tegwin
What do you mean by "the shower does not work"... As in NO water comes out.... or, the water dribbles out and the pump does not start?
Shower pumps are very unstable if you have any air getting into the pipework... is it possible you have a tiny leak somewhere allowing air to form
around the switches in the pump?
No water comes out of the shower at all Although it may be possible there's a tiny leak somewhere, I doubt that air would form around the
pump switches. If it's a sticky valve, can it be stripped down and repaired?
Phil
Nick DV - 31/10/11 at 01:38 PM
From your diagram, air is not the problem. If you have isolator valves either side of the pump, remove the pipes and check if water is getting there.
If it is, reconnect the pipes and then disconnect pipes to mixer. If you get flow at this point, then problem is in mixer. I am assuming that the hot
water system in the rest of the house is ok.
Cheers, Nick 
bob tatt - 31/10/11 at 01:40 PM
Can you vet any water from the shower if you drop the hose down as low as it will go if so you don't have enough head to make the flow switches
trigger. Although it will do this from new. Is the hot water connection as per diagram if so it could be air that has been dragged in and nacked the
pump over time, the hot connection should be via a warix or Essex flange as these don't pull air into the pump .
If this isn't the case I would suspect the valve they sometimes have filters in which can get blocked reducing flow and stopping the pump from
kicking in.
So check all these first.
Rob
plentywahalla - 31/10/11 at 06:42 PM
I'm not a plumber but I have installed a similar set-up and I think the answer is quite simple. If it is a salamander pump the flow switch is
simply a shuttle with a magnet which switches a reed switch to a transisitor. This need a steady flow of water to lift the shuttle and switch the pump
on.
If your diagram is correct there is vitually zero head between the bottom of the header tank and the top of the shower head. There will simply not be
enough flow to start the pump.
One solution would be to supply the cold water to the pump direct from the mains instead of from the hader tank. The cold water flow will always
trigger the pump and the pump will still regulate the flow.
Thats how I set mine up and it works fine.
JoelP - 31/10/11 at 07:20 PM
^that sounds like it to me, a bit of smeg on the filters would easily stop the flow with that little head pressing it through.
bob tatt - 31/10/11 at 07:33 PM
I'm not a plumber but I have installed a similar set-up and I think the answer is quite simple. If it is a salamander pump the flow switch is
simply a shuttle with a magnet which switches a reed switch to a transisitor. This need a steady flow of water to lift the shuttle and switch the pump
on.
If your diagram is correct there is vitually zero head between the bottom of the header tank and the top of the shower head. There will simply not be
enough flow to start the pump.
One solution would be to supply the cold water to the pump direct from the mains instead of from the hader tank. The cold water flow will always
trigger the pump and the pump will still regulate the flow.
Thats how I set mine up and it works fine.
One small problem with running cold main direct to the pump it's against water regs and could cause contamination of the main plus the pump is
not designed to take that pressure so will eventually fail and leak. For anybody reading this the only
Way to do it correctly with a very small head is to fit a negative head pump and not direct to the mains
Going back to the original problem of hellfires check what I have suggested and then repost your findings.
Hth rob
plentywahalla - 31/10/11 at 08:14 PM
quote:
Originally posted by bob tatt
I'm not a plumber but I have installed a similar set-up and I think the answer is quite simple. If it is a salamander pump the flow switch is
simply a shuttle with a magnet which switches a reed switch to a transisitor. This need a steady flow of water to lift the shuttle and switch the pump
on.
If your diagram is correct there is vitually zero head between the bottom of the header tank and the top of the shower head. There will simply not be
enough flow to start the pump.
One solution would be to supply the cold water to the pump direct from the mains instead of from the hader tank. The cold water flow will always
trigger the pump and the pump will still regulate the flow.
Thats how I set mine up and it works fine.
One small problem with running cold main direct to the pump it's against water regs and could cause contamination of the main plus the pump is
not designed to take that pressure so will eventually fail and leak. For anybody reading this the only
Way to do it correctly with a very small head is to fit a negative head pump and not direct to the mains
Going back to the original problem of hellfires check what I have suggested and then repost your findings.
Hth rob
A check valve in the cold water supply will prevent any contamination. A pressure reducing valve will bring mains down to 1.5 bar which is what the
pump will deliver.
I said I was not a plumber ... but I know what I had to do to make mine work.
Rules are for the guidance of wise men ... and the observance of fools.
Hellfire - 31/10/11 at 08:26 PM
The pump is a Stuart Turner pump so not sure if it works the same way as a Salamander pump..... There is approximately 6" between the bottom of
the tank and the highest point of the shower and unfortunately the shower head is fixed, so I can't drop it lower to check the flow switches.
I've previously checked if the pump is dragging in air and it appears to be fine. The hot water connection is via a SALAMANDER
S TYPE Surrey Flange 22mm Top Entry DZR | eBay
from the top of the tank. I'll check the shower valve to see if it has a filter fitted but
I don't recall reading about or seeing one in the destruction manual........
Phil
bob tatt - 1/11/11 at 08:29 AM
Rules are for the guidance of wise men ... and the observance of fools.
That works in theory until something goes wrong. Water regs are there for a reason mostly because some ( wise man ) has thought they knew better and
someone has ended up hurt or Ill through a general lack of knowledge by the wise man. No doubt you also service and install your own gas appliances as
well.
A little information usually gleaned from the Internet or a mate down the pub is a dangerous thing jn the wrong hands.
