Please help!! Shower pump only works if lower the head

[Budice54]

Hi I'm hoping someone can help or at least point me in the right direction.
I have a plumbase 2.0 bar shower pump fitted in my airing cupboard at bottom. It has a dedicated 22mm cold feed from cold water tank in loft and a 22mm hot water supply fed from a surry flange. It then runs off in 22 mm under the floor boards about 2 meters until it reaches the bathroom where it goes to 15mm and runs up toward the shower mixer. The shower mixer has a fixed head and and smaller movable head. My problem is when I go to use the shower nothing happens unless I move the shower head down or give it a really good shake. Another problem which I'm sure is linked is sometimes when u turn the hot tap on in the kitchen the shower pump will start for about a second and sometime pulse every couple of seconds.
I though this could be air and have removed the heads and runs the water through and have never heard air gurgling and it has never fixed the problem so any help would be much appreciated. Hope ive included enough info! Thanks

 

[footprints]

This is one of those faults where you really need somebody on site to sort it out.

Has it worked ok before? How old is it?

If the fault was from installation it may be you do not have enough static head of water to trigger the flow switches in the pump.

Static head is the distance from the water level in the loft tank to the highest draw off (shower head) the effective head (pressure) of water will also be reduced slightly by any restrictions caused by the pipe run itself.

Check the minimum head required for your pump and compare it with the actual head that you have, if it’s right on the border line, the fact that dropping the outlet and so increasing the static head gets it going, suggests that may be the trouble.

The flow switch (it is a small magnetic device that moves when water flows and switches on the pump) might be faulty but you may need to call in the pump manufacturers at that point.

If the pump is in warranty, you have the required head and as it sounds like it has been installed with a suitable flange the makers would be your best bet.

If it is not new, simply descaling the shower head may be all it requires.

 

[ALEC1]

insufficent flow of water to turn on the pump..what is the distance between the tank in the roof and top of the shower..

best solution is negative head pump...

 

[Budice54]

Hi, the shower head is about a foot below bathroom ceiling and then the tank is raised in the loft about half a foot so I guess about a foot and half, mayb a bit more, I thought brocade of this set up I needed a poster rad pump? Thanks

 

[Budice54]

Hi I will have a look at instructions later and find out about head pressure. If it is this what can I do other than moving the shower down? Thanks

 

[footprints]

The measurement is from the top of the water level in the tank so if you have about a foot and a half to the bottom of the tank there will be about the same in the tank so you have around three feet or just under a metre head.

Raising the tank is one option, dropping the shower is not practical by much unless you want to shower on your knees

A negative head pump is perhaps the answer if it is confirmed the head is too low.

 

[Budice54]

Hi sorry for the late reply, ok from the top water level on the tank to the top of the higjest shower head It's about 3 and half foot, and just under a foot more for the other shower head. The data sheet tell me the head should me 2-10m so I about 6 and half foot! Sound like this could be my problem although it sometimes works.

Also I've noticed in the manual it said pipework should be run up and over and not under the floor boards. Oops!!

So my questions are,
Would a negative head pump solve my problem?
If I ran the pipework up as over and down the wall to the shower (not impossible but would do it witht the misses out) and kept same pump would that help?
If I had a negative head pump would I still need to run the pipework up and over?
Would doin either of the previous questions stop the problem where I turn the kitchen tap on and the pump starts up for a second?

Thanks again all that helped

 

[gigz]

If its been in a while and worked ok i would check for blocked filters first, these could be in-line or just meshed washers on the pump connectors.

 

[Budice54]

Hi not its only been in about 3 months and i cleaned the filters on the pump yesterday! I assume the shower unit mixer must have some filters, haven't cleaned them yet. The other option I forgot to say would be easing the tank in the loft, I assume that's just the case of extending pipework andounting the tank on a wooden platform?

 

[Charnwood]

Raising the tank will give very little improvement. As suggested, a negative head pump is the best option.
2 metre head, 0.2 bar - I wee better than that.

 

[Budice54]

Yeah but if I raised the tank to make the head 2 meters wouldn't that then make my 2 bar pump work properly? Which requires min 2meter head! I may be wrong but I think I read somewhere 2 bar is same as 20 meter head?

 

[Budice54]

Also would a negative head pump still sit in the floor on my airing cupboard o would it have to be installed above the cwt?

 

[footprints]

I think another pump that will work with the low head is the way to go. Was it fitted by you or a plumber, if a plumber you have some cause for complaint if he supplied it.

If you can raise the tank to get the min 2 metre head chances are it will work.
Measure what distance you have to drop the shower head to get it working that will give you some idea how much the tank needs to go up, but remember if it only just works, in a few years time with wear and any deposits in the pipe it may not.

Frankly I can't see any difference between going up and over or down and up with the supplies as long as no air traps are created

 

[Budice54]

No I fitted it as I thought I knew what I was doing!lol so am I right thinking I still need a positive head pump but 1 that work with a head less than 1 meter? I dnt think there are any air pockets, I've never heard air gurgling out of the shower or spluttering? Do you think this would solve the problem where sometimes if I turn the tap on in the kitchen it starts for a second or this another issue?

 

[Galoka]

2m head seems a lot to me - I've been looking at shower pumps a lot lately as just about to install one,. Both Stuart turner and Salamander for example have min head requirements much lower.

The min head requirement is really just to ensure enough flow through the pump to switch on the pump. It suggests that maybe this pump has a a higher requirement than seems typical. Does it say anything in the instructions re the min flow rate (cos the flow rate will be affected by the pipe runs as well)

If the un pumped flow from the shower head is sufficient, it suggests the pump maybe faulty.

In fact I'd be tempted to just see if they will replace it under warranty anyway.