shower pump issue

AdamMaple

I have a grundos niagara 1.5 bar twin centrifugal positive head pump in my airing cupboard with a cold feed from tank in loft and hot from the cylinder next to the pump. I think it is coming from the side of the tank with warrix flange. I first used the thermostatic mixer shower this weekend and it has been successful for 3 showers. However this morning i used it and the pump did not kick in and no water came out of the shower. I tried turning the temp on the shower to the min and it worked fine (though very cold) turning the hot back up gradually made it warmer but the pressure disapeared and became splutery.
I think I may have an air lock on the hot side.
Is there an easy way I can try to remove this? My pump instructions say use an essex / surrey flange - has the plumber used the wrong kind?

keystone

If the pump didn't kick in that means the flow switch didn't operate. I too think you have air on the hot side but whether its an airlock or whether the pump is sucking air in remains to be seen.

A warix flange fits in the top of the cylinder and is similar to a surrey except that the shower outlet is at the top with the vent on the side wheras the Surrey is the other way round. So no your plumber has not used the wrong type vis a vis a surrey if its fitted in the top of the tank. The surrey also has a different mating arrangement but thats by-the-by and not for here.

An Essex flange would be fitted into the side of the cylinder either to an existing boss or via a hole specially made for it. I'm intrigued that you say that the Warix is fitted to the side of the tank - its designed for the top so if he's used a Warix where he should have used an Essex then yes he has used the wrong type.

Can you provide some pics of the plumbing arrangements around the cylinder specifically those for the shower. I know as a new user you can't post links so upload your images to imageshack or photobucket or similar and paste the link that the host gives you into a post here. Before you hit submit delete the http bit so that the forum software thinks its just text. Then one of us can put the missing part of the url back in again and make your pics appear for comment.

Cheers

AdamMaple

Hi Keystone

Apologies I wrote the post while at work and got it slightly wrong. The hot pipe comes out of the tank as it did before the shower plumbing was installed and the plumber has fitted a 'wessex' flange halfway down the pipe. This then Ts off to the pump.
So I don't believe there are any flanges in the tank. Could this mean that air is getting in?
I found a suggestion online to remove the shower head and lay the hose in the bath, and run the hot then the cold for 2 min with the pump off, then repeat with the pump on. This seemed to solve the problem. I tried the shower a couple of hours later and it was still working but showing signs of spluttering so I guess the air / or problem is coming back.


//imageshack.us/a/img835/7092/29102012353.jpg
(cylinder and pipe work)

//imageshack.us/a/img713/1708/29102012352.jpg
(pump with hot suplly on the right)

//imageshack.us/a/img405/2562/29102012351.jpg
(close up of the wessex flange)
Do you think the plumber should have added an essex flange into the side of the cylinder for a dedicated hot supply to the pump that prevents air getting in, rather than a wessex flange outside the tank?
Thanks for your help

southcoastrgi

keystone

There is a problem fitting either a surrey or a warix because of the way the cylinder is currently piped and he would have had to make changes to that. Due to the cylinder insulation he would have had to cut part of that away to fit an essex.

For me he has taken the lazy way out and just teed it off (if thats what he calls a Wessex flange then, well, OK - bleah!) the hot supply to the taps so is almost inevitably drawing air down the vent pipe.

For me there should also be isolation valves for the supplies very close to the pump. Granted there is one for the hot but I think it should be closer and I can't see one for the cold.

I think you need to call him back. [Adds edit] to repipe it properly.

Cheers

keystone

OK so Southcoast is quicker than me!

southcoastrgi

keystone wrote: »

OK so Southcoast is quicker than me!

& i got my pic the right way round

AdamMaple

Thanks! I called the plumber yesterday but he's on holiday so it will be a few days before he comes back.
He didn't call it a wessex, it says it on the edge of the part. So I assume its a type of flange named after a county.
So it sounds like we've got to the bottom of the problem. What do you think I should get him to do - fit the essex or surrey, or is there something he can add to whats there to prevent the air getting in?
In his defence he did fit a cold isolation - its in the loft just as the pipe leaves the cold tank. Though thinking about it I could do with one of these in the airing cupboard where its a little more accessible.

keystone

AdamMaple wrote: »

What do you think I should get him to do - fit the essex or surrey, or is there something he can add to whats there to prevent the air getting in?

I don't think you should tell him to do anything - let him work it out for himself.

The problem you have is twofold. I've annotated your picture:



At A the vent should go straight up not horizontally. Its clearly been piped to suit the airing cupboard shelves rather than the shelves modified to fit the piping. Thats prolly not his issue though although it impacts on the work he has done for you in fitting the pump. The top of any cylinder has air in it. As you draw off water to the taps some of that air gets into the pipework. You just don't notice it coming out of the taps.

The feeds (hot and cold) for the shower should be separate from all other taps and thats for two reasons. First it stops someone either freezing you or scalding you when in the shower and they turn on a tap. The second is to avoid drawing that air into the pump. In your case (see he has teed into the pipe supplying the taps. So not only might the pump be drawing air down the vent but its also probably collecting air from the top of the cylinder. I hope he's also done a separate feed for the cold by making a new connection into the storage tank thats separate from the tap supply but obviously we can't see that from the pics.

For your info the pic below shows the four ways in which the hot can be piped. In the diagram T is to the taps, V is the vent and the pump is the circle with the triangle in it.



In configuration A the pump supply is teed off the vent but its rising before it goes vertical so that any air coming out of the cylinder travels along the top surface of the pipe towards the vent and doesn't get drawn down to the pump. As you can see the tap supply is separate.

In configuration B using a surrey flange the pump supply is again separate from the tap supply. The Surrey flange has two inlet pipes within the cylinder. The one for the pump is far longer than the other which ultimately feeds the taps and being longer sticks down into the water thus no air is drawn into the pump.

In configuration C using an Essex flange (the pipe can be connected to a factory fitted boss if one exists) the flange pipe extends into the water in the cylinder below the air pocket so no air is drawn in.

Configuration D is for a Warix flange where, as advised previously, the pump supply comes out of the top of the flange and the tap supply out of the side ie the other way round to the Surrey.

Note that in all cases the vent pipe is off the tap supply and not the pump supply.

Hope that makes sense and he should know all this without prompting - you are paying him to do the job after all.

In his defence he did fit a cold isolation - its in the loft just as the pipe leaves the cold tank. Though thinking about it I could do with one of these in the airing cupboard where its a little more accessible.

Accessibility is the key. Some pump manufacturers wiull just turn around and walk away if called out to a warranty or service call if on arrival they find the isolating valves are not in the immediate vicinity of the pump. As its in the MIs for that company there is no excuse for not doing it. One that I know of insists that isolation should also be provided on the outlets from the pump too so that it can be totally isolated.

Gone on a bit this one (:D) but hope it helps.

Cheers

AdamMaple

Thank you very much for the detailed response. I refurbished our whole house myself and this is the first professional I've had in to do something because I felt out of my depth with flanges and drilling into water tanks. Sounds like I might aswell have done it myself!
I will be chasing up the plumber again tomorrow to get him back out. He better not expect to be able to charge me for this.

Thanks again, will let you know how I get on.

AdamMaple

2 weeks later and I am still trying to get to speak to the plumber!!!
I get through to their office no problem but keep getting told he will call me back.
I'm starting to think they have no intention of helping dispite their website saying they pride themselves on aftercare.
I am re-purging the shower at least once a week now to get rid of the air build up. Looks like I might be attempting a surrey flange for myself. I give up with plumbers now - I was in contact with 3 different ones to do the job in the first place and I did'nt even receive a quote from 2 of them dispite chasing it up!