One shower working, one not...

[Jabberwocky]

I have two upstairs bathrooms running showers connected to a single Aqualisa 3TE 4Bar pump. Initially I had one bathroom attached - then in a recent extension build had a second bathroom built and plumbed into the pump.

The first bathroom works fine - and the pump kicks in correctly every time water is drawn from the shower.

The second bathroom doesn't work. If we attempt to draw water, nothing happens. If I turn the shower on, then go to the first bathroom and turn its shower on then off (thus getting the pump to start) the second bathroom shower starts and the pump stays running happily. When I turn the second shower off the pump stops (as you would expect). If I then try turning it on again - nothing happens.

I can only get the shower in the second bathroom to work by 'kick starting' it by turning something on in the first bathroom.

The first bathroom is closest to the pump.

My suspicion is that the plumbing done to add the second bathroom into the circuit has been done in such a way that allows an airlock to occur.

Anyone seen this before - or know what I should be looking at?

 

[namsag]

Certainly sounds like an airlock. Try letting the showerhead hang low to see if that helps it start

 

[Jabberwocky]

Lowering the shower head doesn't help.

I have attached a picture of the plumbing to the pump. The two pipes from above are the hot and cold gravity feeds. The two pipes heading out of the left side of the picture are to the second bathroom that doesn't work. The two pipes going down in the middle of the picture (one looks white and comes down from the grey T, other has grey join on it) run down to the floor then off to the first bathroom that works okay.

Plumbing to pump

• Jabberwocky
• 16 Mar 2009
• 1

Could the T junction in the middle of the picture be the problem?[/img]

 

[Richard C]

Presumably the pipes to the 1st bathroom run under the floorboards then up to the mixer valve? How are the pipes run to the 2nd bathroom, is it similar; under the floor then up to the mixer or do you have up & over loops down to the shower mixer.

 

[Jabberwocky]

First bathroom - pipes run under floor boards then into Aqualisa shower controller (which sits on the floor under the shower tray). In first bathroom bath, sink and toilet also plumbed into same feed from pump. All work fine - all the time. No up and over loops.

Second bathroom - pipes run under floor boards then straight up and into thermostatic mixer about 1m high. No up and over loops I am aware of here either.

 

[Richard C]

What type of mixer valve do you have in the 2nd bathroom?
You previously said moving the shower head down had no effect on self starting the pump, what type of shower head is it?
Is there fixed pipe work running straight up from the mixer valve to the shower head?
What is the approximate distance from the highest point of any fixed pipe work to the shower head & the underside of your cws tank?

 

[Jabberwocky]

The mixer is an Imperial Thermostatic Bath and Shower Mixer. The pictures attached show the mixer controls. The shower pipe is flexible and attached to the wall outlet shown on the picture (not a fixed pipe right up to the shower head).

I'd estimate the vertical distance from the shower outlet on the wall (highest fixed pipe point of the shower) to the underside of the CWS is about 3m.

Worth noting that if I set the mixer to fill the bath instead of using the shower, I have exactly the same problem with the pump not kicking in as per my original post.

Any help appreciated...

Untitled

• Jabberwocky
• 16 Mar 2009
• 1

Untitled

• Jabberwocky
• 16 Mar 2009
• 1

 

[Richard C]

Sorry been busy. Nothing obviously untoward in what you’ve said so far but it’s obvious that the pressure switches are not kicking in at the moment on the longer pipe runs; very difficult to say why from here. Didn’t have much luck finding any tech. details about the pump other than it’s now an obsolete model; couldn’t find out much tech. regarding the Imperial mixer/diverter valve either.

Do you have any flow from the bath or shower unit without the pump running? There should still be a minimum flow of at least 1 litre/min or the pump pressure switches may not register & kick the pump in. A 3m head is more than adequate but what are the hot/cold water feeds like, presumably all 22mm; does the h/w cylinder have a separate c/w feed from the storage tank? What is the length of the pipe runs to the 2nd bathroom?

I think your problem may lie in the mixer/diverter valve itself; check for possible restrictions in the valve & does it have a minimum operating pressure?

 

[Jabberwocky]

Richard - thanks for keeping going with this, its annoying us no end so I am keen to find an answer!

To answer your questions:

Pretty certain mixer (Imperial 3 control 2 way mixer - Modern) is low pressure friendly with minimum of 0.1 Bar required. Have emailed their support to confirm.

After any period of time without use, the 2nd bathroom doesn't get any flow even if the pump is switched off (the pump allows flow through when not powered, and first bathroom works fine when pump off, just lower pressure output).

However, I tried the following --- with the pump on, turn tap on in bathroom 1 and then bath on in bathroom 2, everything starts to flow at high pressure. Turn power to pump off - water in both bathrooms keeps flowing at low pressure. Turn bathroom 1 tap off - bathroom 2 keeps flowing at low pressure. Turn mixer off in bathroom 2, then back on again - water flows. Turn off and wait 30 seconds then back on - water flows. 1 minute - water flows. Wait for much longer however and when you try to turn back on, nothing happens. In this scenario, seem to be able to leave a longer gap before turning back on with mixer set to hot than cold - but if you wait long enough between turning off then on again, neither works.

All pipes are 22mm.

h/w cylinder has seperate feed from storage tank

Length of runs to second bathroom much longer than to first. Haven't measured exactly (can if important) but I'd say approx 5m to first bathroom compared with 15m to second bathroom.

Guess you don't think its an airlock issue then?

 

[Richard C]

Richard - thanks for keeping going with this, its annoying us no end so I am keen to find an answer!

No problem.

To answer your questions:
Pretty certain mixer (Imperial 3 control 2 way mixer - Modern) is low pressure friendly with minimum of 0.1 Bar required. Have emailed their support to confirm.

Seems OK but no flow at the 2nd bathroom with the pump off = zero pressure & the pump pressure switches won’t kick in; minimum flow is around 1 litre/min without the pump running unless you have a negative head pump arrangement.

After any period of time without use, the 2nd bathroom doesn't get any flow even if the pump is switched off (the pump allows flow through when not powered, and first bathroom works fine when pump off, just lower pressure output).
However, I tried the following --- with the pump on, turn tap on in bathroom 1 and then bath on in bathroom 2, everything starts to flow at high pressure. Turn power to pump off - water in both bathrooms keeps flowing at low pressure. Turn bathroom 1 tap off - bathroom 2 keeps flowing at low pressure. Turn mixer off in bathroom 2, then back on again - water flows. Turn off and wait 30 seconds then back on - water flows. 1 minute - water flows. Wait for much longer however and when you try to turn back on, nothing happens. In this scenario, seem to be able to leave a longer gap before turning back on with mixer set to hot than cold - but if you wait long enough between turning off then on again, neither works.

Low pressure feed to both bathrooms will tend to keep on going once you start it with the pump, it’s just a simple siphon. I would say you definitely have a flow problem somewhere in the 2nd bathroom pipe work, mixer/diverter or shower head. Quiet what it is almost impossible to diagnose from here & you need to run through the system looking for whatever seems to be causing such a dramatic pressure drop.

All pipes are 22mm. h/w cylinder has seperate feed from storage tank

Noted; I can see the feed pipe from the pump is 22mm but does this run all the way to the 2nd bathroom mixer/diverter? Or has it been dropped to 15mm at some point!

Length of runs to second bathroom much longer than to first. Haven't measured exactly (can if important) but I'd say approx 5m to first bathroom compared with 15m to second bathroom.

Shouldn’t really be a problem.

Guess you don't think its an airlock issue then?

From what you’ve said I don’t think so; under floor pipe work is the ideal; you only really start to get air lock problems if you;
• Don’t have a recognised connection at the hwc & I admit I haven’t actually asked what you have yet!
• Introduce inverted loops before the pump
• Have up & over loops the to the mixer or shower head without air vents
• Run up & over pipe work too close to the cws tank which will, in certain circumstances, effectively give you a negative head meaning the pump pressure switches won’t kick in.

As I said above, you seem to be suffering a serious drop in pressure at the 2nd bathroom mixer/diverter valve or in the pipe work that feeds it which is preventing the pump pressure switches activating; can I ask who installed the system?

 

[Jabberwocky]

System was installed by a plumber who was part of a builders team that did some extension work for us last year. We fell out with the plumber at the end of the project over poor quality finishing off in the bathroom (sloppy sealant work etc) and would not want him back in the house. This problem didn't come to light for many months as we didn't use the second bathroom for a while. Not keen to get the builder back as we don't want the plumber in the house again!

Guess I may need to get a plumber I trust in to take a look?

I am tied up today - but as soon as get a chance will do a flow test on each of the bathrooms (without pump) to see what rate of flow we get when they are running and if its different.

Thanks again.

 

[WSPH]

i have not read any of the above but i have come across this problem before with cowboy installers. that thermostatic shower valve you have has either a single or double check valve or you have one somewhere amongs the pipe work in the 2nd bathroom which is not allowing the pump to kick in.

undo the shower head off the shower hose and open the tap. and suck the water in, becareful though as your pump is 4 bars. i would not recommend doing this unless your experienced.

 

[Richard C]

that thermostatic shower valve you have has either a single or double check valve

If it has there's your problem!