Shower pump issues

[Bongowhack]

Hi all, I've got issues with my shower pump and wondered if anyone could give me some advice on how to resolve the problem?

When we bought our new-build house from Persimmon (oh how I wish we'd just built our own!) the water pressure in the shower was terrible so we asked what could be done about it. The site foreman arranged for a pump to be fitted next to the hot water tank and it worked fine for a while but then started playing up.

The hot water tank is in the airing cupboard just next to the en-suite where the shower in question is located. The tank is fed from the cold water supply in the loft.

Early problems were relatively easily fixed - the pump wouldn't work straight away when you turned the shower on so we dropped the shower head down to the tray to allow a better flow of water and the pump would kick in.

When that failed, we'd turn the temperature of the shower all the way down to allow more cold water through the pump - it would then kick in and we'd adjust the temperature after it was running.

As time went on even this wouldn't get the pump going so we had to turn on the shower and then increase the flow of cold water through the pump by opening the valve in the airing cupboard to get it to start. This would drastically lower the temperature of the shower so we then have to decrease the cold input to the pump to get the shower back to a comfortable temperature.

And it's gotten even worse over time - very often the pump will cut out when the shower is in use and to get it back on, you've got to drop the shower head and then increase the cold flow into the pump in the cupboard again to get it to kick in and then reduce it once more so the temperature is comfortable. There is no control of the temperature of the water using the shower controls anymore and it can only be adjusted by altering the cold input to the pump.

Having taken all of the above into account I assumed it's something to do with the hot water supply going into the pump so I investigated over time and came across people suggesting the use of a Surrey Flange or similar to prevent airlocks in the system (I've already cleaned the filters etc). I thought it may be a bit too much for me to handle so I contacted a local plumber (highly recommended on Checkatrade) to come and have a look for me. When he came out, he told me that a Surrey Flange has a male thread on it and, as my tank also has a male thread, it couldn't be fitted. The only other options open to me would be to fit an electric shower (but according to him the pressure is really low with an electric), attempt to fit an Essex Flange to the side of the tank (but the twice he's tried to do this, it failed), replace the hot tank with one fitted with a female thread on the top (~£800) or better still, replace the whole system with a combi boiler for about £2k.

I have a feeling this isn't 100% true and that there must be some other valve/flange/fitting that can be connected to my tank or the pipes in the system to achieve the same reduction in air coming through the hot feed. I'm well aware that this is a cheap pump & it might have been damaged by the aerated supply or just given up the ghost cos it's a bit crap but if I'm going to have to replace it, I'll still need to have a new one installed correctly so tackling the hot feed is going to be my first job.

I'll upload a couple of images of the set up inside the airing cupboard to show what's there already and I'd appreciate it if someone could point me in the right direction of how to rectify the situation.

Thanks a lot for any advice.

Mike

 

[Madrab]

He's talking rubbish, you can get female adapters for surrey flanges or alternatively use a female york flange, that will fit the male connector on top of the cylinder. Does that male connector unscrew out of the top of the cylinder or is it fixed?

If he's at all creative tho he could also use that immersion blanking cap, core/drill a 22mm hole into the brass nut, solder in a length of 22mm pipe dipping into the water by about 2-3" and use that as a dedicated shower supply.

Bristan are not usually quoted for their shower pumps and the way yours is setup then there's a real possibility that it's drawing in air which has caused issues.

You say he's tried to fit an essex flange twice and it's failed both times?? How did the installation fail? Have you been left with 2 holes in your cylinder?

 

[Bongowhack]

Hi there Madrab, thanks for the reply. This is why tradesmen get a bad name, I get sick and then end up having to do everything myself!

Anyways, the male connector out the top of the tank is fixed, it's part of the tank as far as I can tell. The top of the connector will be about 3 inches proud of the top of the tank.

And sorry for the confusion over the Essex flange, he reckoned he's tried to fit these to other tanks twice in the past (not mine) but he said when he did, both tanks deformed and leaked and he ended up having to replace them anyways.

What would you suggest as the easiest fix & could you possibly point me in the right direction to the particular parts I'd need?

Many thanks,

Mike.

 

[Madrab]

Ah OK. Well fitting essex flanges are a delicate process and can be tricky to fit correctly.

You'll be looking for one of these to be fitted to the top of the tank - http://www.anchorpumps.com/grundfos-watermill-york-flange-22mm-1?gclid=COTe-vDNkMsCFeUV0wods0ULFg

You will need to check dimensions, pipe sizes to get the correct fitting.

Another alternative is, if the pipe is too long, is to cut the outlet down and then fit a female compression iron, then fit a standard surrey or similar type.

There are many alternatives that your plumber could be considering IMO.

 

[Groovejet]

This just seems one big mess from start.
It looks like no thought has gone into the correct fitting of the pump as it was a after thought.
The flow switches in the pump won't turn the shower on if certain measurements ha nt been adhered to.

The cold water storage tank may be to low in loft In Relation to the distance between the bottom of tank and the shower head itself

 

[Groovejet]

The pump must have been fitted wrong.
The first issue would be to check the distance between the base of the cold water storage tank to the shower head.
If this distance is less than 2foot then it won't work properly anyway.
The flow switch in pump needs a minimum flow rate acting on it, about 1 litre min natural flow,otherwise it won't work, and you end up lowering the shower head, to get it started.

The system may be bordering on Negative pressure, and what you have got is a positive pump.

The top of the cylinder isn't standard..whatever!!!
So fitting a survey may be a pain because it may not fit into the actual fitting as a flange has a dip tube on which may foul the existing cylinder connection.
Made abs suggestion looks it will fit ok,

 

[Bongowhack]

Thanks again for the advice, I've arranged for another plumber to stop by tomorrow and have a look to see what he can do - I'll mention what's been said on here so far & hopefully he won't spin a load of lies like the last bloke.

To answer your question:
I believe the distance between the bottom of the tank & the shower head is more than two foot but as I can't remember whether the tank in the loft is raised at all, it might not be much more. To be honest I didn't know the shower was fed by the tank in the loft, I assumed it was straight from the mains.

Is there such a thing as a negative pressure pump?

And as for the cylinder being anything but standard, it doesn't surprise me at all that Persimmon have just thrown stuff together any old how - I'm well used to finding half-done or bodged jobs round the place over the past few years. I often think I would've been better off learning a bunch of trades & building the place from scratch myself!

Mike.

 

[Madrab]

It's not just how close the shower head is to the cold tank but the shower pipework, which from the pic seems to run up into the attic space too.
Yes, you get negative/universal pumps but tend to be more expensive. A negative head switch could be utilised too. Turns a positive pump into a universal by a switch to activate the pump rather that relying on the flow switches. All pump fed showers are fed by gravity from a cold tank in the loft, cold feed direct to the pump, and cold feed to the hot water cylinder and then to the pump.

You do get male fittings on HW cylinders, they're just rarer than female. Again, there are more than a few options that can be incorporated to sort your shower out and a good plumber should be able to sort it out for you.

 

[stem]

This installation was done by someone who doesn't understand the basic concept of stored hot water systems. If the hot water supply to the pump is taken from the normal cylinder outlet, it should be configured as below. You can get away with less incline than shown, but the important thing is that the connection to the pump is teed in from below, as air bubbles will rise to the top to the pipe. This could have been easily done, but yours is connected to the side for some bizarre reason.

Untitled

• stem
• 1 Feb 2011
• 1

or, it could have been connected further down closer to the pump well away from the vent, like this.

Untitled

• stem
• 1 Feb 2011
• 5

Another way would be to use a flange designed for purpose. Although as you don't have an immersion heater fitted, Madrab's suggestion of using the blanking plate and extending a pipe by a few inches through it will achieve exactly the same thing.

Shower Flange

• stem
• 18 Aug 2009
• 3

 

[Bongowhack]

Thanks again for your input chaps. Having decided not to use a hammer to crack a nut and replace my whole heating system with a combi to the tune of 2 grand, I had another look on Checkatrade & found another plumber who, according to their profile, deals with shower pumps.

The young Aussie guy who came out didn't have a clue about Surrey/York flanges and could see nothing wrong with the current setup. He said it was probably just a bad pump but admitted he didn't know much about them. When I pushed him further about the flanges, he took a few pictures of the pipe work, sent them to his gaffer & gave him a ring.

Sure enough, the boss recommended fitting a Surrey flange and then replacing the pump if needs be. He said he'd price up the job & get back to me that afternoon - a week later and I'm still waiting.

What is it with Cowboy F**knuts?! I can't keep taking time out to get some numpty in to cast his useless eye over something he has no damn clue about, only to recommend blowing 6 weeks wages on something completely unnecessary! Damn I'm sick of this!

I'm now onto my 3rd plumber who is a friend of a friend so hopefully he'll actually know what he's talking about and be able to do something about this (what I assume to be fairly simple, based on advice on here) problem.

Thanks again for your help, I'll keep you posted on any progress.