Shower Pump not pumping hot water

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Hi all,

I recently had my bathroom updated from the original because we wanted a nice powerful shower - and because we have a gravity fed system we opted for a shower pump. Pretty much after the first week we had problems in that the pump would only operate if the thermostat on the shower was turned to cold - if you tried to make it hot the pump would stop.

The only way we could get it to work would be to loosen off the hot water valve into the pump and bleed it until hot water came through at which point the pump would kick in.

This isn't ideal - actually its a total pain in the a***. Just last week I had to have the pump replaced because the original began to leak - I thought this may have been the cause and once replaced the problem might be fixed - but no it worked once it was replaced but the next day the same problem occurred.

I've spoke to the plumber who fitted the new one and he seems to think that the hot water tank is full of air which is getting into the pump and preventing it from working until it is bled.

Times are a bit hard at the moment and I cant afford another plumbing bill - is there anyway I can fix this myself?

And also does anyone have any similar experience with this and what may be the cause?

Thanks for any help on this.

PS the pump is a deva pum40

Thanks again.

Tim
 
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I have also installed a pump for my shower.
I am no expert but it sounds like you maybe drawing air from the hot water cylinder in the airing cupboard.
Do you have a flange fitted into the cylinder? This will have 2 exit points, 1 to your normal gravity fed hot water (Bath tap) and 1 should go to your pump. This flange should hep reduce air intake to your pump.
Hope this helps.
 
Is it just pumped HW or both H&C water? Heating water releases oxygen in the form of bubbles into the HW cylinder so it’s true to say that all HWC will have air in them, it’s what your plumber did to counteract this which is important. Air is vented off the top of the tank (into the CWS tank) where the hot water supply take off is normally taken from, a pumped system must have the hot water take off through either a proprietary anti-air flange in the top of the tank or, preferably, via an independent side fitting (Essex) flange.

It very much sounds as if you have a basic problem with pump installation &/or with the installation pipe work but it’s impossible to say where the problem may lie without a lot more information/diagrams on the pump, supply & delivery pipe work size & installation. It’s a sad fact that not all plumbers know how to successfully install shower pumps; in fact some haven’t got a clue :rolleyes:
 
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Is it just pumped HW or both H&C water? Heating water releases oxygen in the form of bubbles into the HW cylinder so it’s true to say that all HWC will have air in them, it’s what your plumber did to counteract this which is important. Air is vented off the top of the tank (into the CWS tank) where the hot water supply take off is normally taken from, a pumped system must have the hot water take off through either a proprietary anti-air flange in the top of the tank or, preferably, via an independent side fitting (Essex) flange.

It very much sounds as if you have a basic problem with pump installation &/or with the installation pipe work but it’s impossible to say where the problem may lie without a lot more information/diagrams on the pump, supply & delivery pipe work size & installation. It’s a sad fact that not all plumbers know how to successfully install shower pumps; in fact some haven’t got a clue :rolleyes:

I'd agree with that - the second plumber I got out to replace the pump told me that who ever had fitted it skimped on the the installation. And I doubt whether they did anything to counter the air issue you mentioned.

The pump, pumps both hot and cold - the cold water works perfectly.

When I spoke to the plumber who replaced it this morning he explained that he could drain the air from the hot water tank but it would take him a couple of hours - and with him charging 40 pounds an hour I can't afford that and from what you say this would only temporarily solve the problem until more air builds up from the hot water releasing oxygen into the tank - this leads me to believe that this plumber a) doesn't really know what he's talking about, but is happy to charge me anyway or b) see a)

I take it this issue is beyond my ability as someone who knows nothing about plumbing to repair?
 
Unless you have a presurised HW system, (which seems unlikely if you’ve a pump fitted) you must have a vent on the top of the cylinder making the cylinder self venting so air cannot build up inside! If you have a pressurised HW system, you can’t fit a pump to it anyway! Without knowing what you’ve currently got, impossible to say how easy it would be to fix but, from what he’s told you, plumber b) doesn’t exactly fill me with confidence either. Did he not advise what the problem was, what you need to do to correct it & offer to quote?

If you’ve no plumbing experience at all then it probably would be beyond your ability but if the problem is not corrected, you could be fitting pump number 3 before very long. But if you can post some pictures of the pump installation, HW cylinder & associated pipework & say where the CW storage tank is then we may get somewhere.
 
Unless you have a presurised HW system, (which seems unlikely if you’ve a pump fitted) you must have a vent on the top of the cylinder making the cylinder self venting so air cannot build up inside! If you have a pressurised HW system, you can’t fit a pump to it anyway! Without knowing what you’ve currently got, impossible to say how easy it would be to fix but, from what he’s told you, plumber b) doesn’t exactly fill me with confidence either. Did he not advise what the problem was, what you need to do to correct it & offer to quote?

If you’ve no plumbing experience at all then it probably would be beyond your ability but if the problem is not corrected, you could be fitting pump number 3 before very long. But if you can post some pictures of the pump installation, HW cylinder & associated pipework & say where the CW storage tank is then we may get somewhere.

I don't think it is a pressurized hws I believe its gravity fed. We had to get an extra cold water tank fitted in the loft and there is also one above the pump, the hot water tank is below the pump.

Plumber B simply said there was air in the hot water tank and for 80 quid he could flush out the air. But from whats been said I doubt this will fix the issue.

I will happily take pictures tonight if that will help diagnose the problem.

Thanks

Tim
 
We had to get an extra cold water tank fitted in the loft and there is also one above the pump, the hot water tank is below the pump.
Some vertical dimensions would help. Is the pump also above the shower head? If so by how much?

Plumber B simply said there was air in the hot water tank and for 80 quid he could flush out the air.
Sounds like a load of browlocks to me; more likely he’s talking about bleeding up & over pipe work but that would only be temporary if I'm right with the next bit. From what you’ve said already, I’ve got a good idea what your problem is; with the pump above the HW cylinder, a side fitting Essex flange must be used on the cylinder with an anti-gravity loop, not a top fitting flange. You would also normally have a non return valve to the HW feed from the pump but, most importantly, you must have auto air vents fitted at the highest points in the pipe work before it drops back down again to feed the shower head; this is where the air gets trapped & is most likely what’s causing you problem.

Lets have some decent pics. of everything.
 
We had to get an extra cold water tank fitted in the loft and there is also one above the pump, the hot water tank is below the pump.
Some vertical dimensions would help. Is the pump also above the shower head? If so by how much?

Plumber B simply said there was air in the hot water tank and for 80 quid he could flush out the air.
Sounds like a load of browlocks to me; more likely he’s talking about bleeding up & over pipe work but that would only be temporary if I'm right with the next bit. From what you’ve said already, I’ve got a good idea what your problem is; with the pump above the HW cylinder, a side fitting Essex flange must be used on the cylinder with an anti-gravity loop, not a top fitting flange. You would also normally have a non return valve to the HW feed from the pump but, most importantly, you must have auto air vents fitted at the highest points in the pipe work before it drops back down again to feed the shower head; this is where the air gets trapped & is most likely what’s causing you problem.

Lets have some decent pics. of everything.

Hi,

The pump is at a lower level that the shower head - its also at the other end of the bathroom. I took some pics last night but forgot to bring my camera to work - I'll post them on when I get home.

Thanks for all your replies.
 
Did you managed to get this sorted?
Have included a pic of my set up which I did myself.
You can see the flange coming out of the top of the cylinder with the pipe going to the back of the airing cupboard wall feeding the pump.
Hope this is of use to you.
 
Sorry the pics dont seem to upload.
Here is the link.

//www.diynot.com/network/Jayluvit/albums/[/QUOTE]
The OP's pump is installed above the HW cylinder so your system install is not relevant to his problem. He seems to have disappeared anyway!

Re your pic; Gate valves are not full bore & restrict flow, only full bore (lever) isolation valves should not be used on pumped systems. ;)
 
Hi Richard,
The reason for my posting was that he didnt know what a flange was and I posted the picture for him to view this item.
As regards to the gate valves, Salamander give an option (extra cost of course) to have the flexi pipe part that comes with the pump supplied with isolating valves. So if they recommend this as part of their set up then I cant see a problem with the gate valves which have more of an opening then the isolating ones.
Anyway as you say he seems to of vanished so we wont know if he solved his issue.
 
The reason for my posting was that he didnt know what a flange was and I posted the picture for him to view this item.
Unfortunately with the pump above the HWC it needs to be a side fitting Essex flange, not a top fit flange.
 
Which I am aware of but he didnt even know what a flange was.
For all we know the person installing it could of just teed it off of the hot water pipe.
 

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