Gravity Fed Shower Problems

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Hello

Just moved house which has a traditional gravity fed hot water system, with an old back boiler.

This all works fine and has been regularly serviced (except an issue with one of the motorised valves which is unrelated to this post).

The hot and cold water from the taps is fine, but the shower is pretty much unusable.

It has a separate feed with a Stuart Turner twin pump which is on the floor next to the cylinder. The pipe for the hot comes directly off the main pipe that comes out of the top of the cylinder, at a right angle, and goes straight into 15mm. I don't think there is any Surrey etc. type flange. The cold feed from the tank is also 15mm, and both pipes out of the pump are also 15mm, and go up into the loft void and then across to the shower and back down the wall. The drop from the tank to the shower head is about a metre at best.

The pump runs when the shower is turned on, but makes no visible difference, at all. I only know it's running by the noise.

The shower unit itself is a thermostatic bar type, clearly pretty old due to the build up of limescale (it is a very hard water area).

I initially replaced the head and hose as the nozzles where limescaled up, which made no difference. I also took the shower off the wall, after isolating it, and turned the water flow back on, the water coming out seemed barely adequate but more than comes out of the shower head. I took the inlet filters and valve out of the shower, cleaned limescale off them, and replaced, which seemed to make no difference.

I don't think it's air in the pipes going into the loft and back down, as I tried taking the shower head off and sucking water through and it made no difference.

In fact, the situation has got worse, as now water will not flow from the shower head when it is above waist height, and is only (barely) usable by crouching down in the shower tray, whereas it used to come out in the rail at over head height.

I am planning to redo the whole bathroom, probably with an electric shower, and eventually replace the whole system with a combi, so I am after a usable, cheap solution which will allow us to wash until the new bathroom is done.

I know that this set up is never going to be a great shower, but I can't believe it was this bad when installed and considered acceptable.

I was going to try replacing the shower bar, possibly with a manual mixer. Do these allow more flow than the thermostatic types?

Could there be something in the water tank blocking the cold flow into the pump? The gate valve on this pipe appears to be broken as the red wheel just spins, although I can see the spindle turning. Could this be stuck partially open?

Is the issue merely that all the 15mm pipework is just too restrictive to get enough flow into the pump? I understand that the pipes feeding the pump should be 22mm according to Stuart Turner.

There is a pipe coming out of the cylinder about halfway up it, wich appears to be capped off. I don't know what this is, could it be used for an Essex style flange to reduce air in the shower feed (if that is even the problem)?

20180705_071939.jpg


Thank you to any one who has read this far. Any suggestions or tips would be great. I'm no plumber, so if replacing the feed pipes with 22mm is the only answer then I would get someone in, but as I say I will be replacing everything so I don't want to throw money at this.

Cheers
 
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Firstly, the most common Stuart Turner pump to have 22mm fittings is the Monsoon, an expensive and very good pump. It has basket type strainers in the inlet fittings, which you should check and clean to eliminate debris as a very likely cause of your symptoms. The defective gate valve you described may well be stuck/broken in an 'almost' closed position, so I suggest you buy a pair of 1/4 turn FULL BORE valves and replace those on both the HOT and COLD inlets. This will also enable convenient servicing of the inlet strainers now, and after a few minutes of full flow being re-achieved. This is because the flow rate, once restored, will deposit more debris into the inlet strainers! At this stage you may find that an increase to 22mm pipe is not necessary, though I recommend you take advice before rushing to a combination boiler.
 
An electric shower would be a bad move. Electricity costs around 3 times the cost of gas.
 
Thanks for your replies.

Meldrewsmate:

It is a Showermate pump, the inlet hoses are 15mm, but Stuart Turner's website reccommends/insists on 22mm for the runs before these.

There are no inlet strainers, perhaps there is a build up of debris in the inlet hoses which could be cleared out?

There is no gate valve on the hot water inlet, just an isolation valve.

I know they are expensive decent pumps, which is why I was so surprised that the shower is so bad.

Regarding the combi boiler, this is off in the future rather than imminent. This is with a view to improving the efficiency of the whole system rather than anything to do with the shower. The back boiler, while old, seems surprisingly good, I haven't lived in a house with a hot water cylinder since my parents, so this is a bit new to me. Can I ask if you mean you think a combi would not be worth fitting?

Winston:

A fair point. It's just what I am used to, it doesn't have to be electric, just a decent shower.
 
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Assuming limescale/debris blockage is the issue, without the strainers, where is is this likely to accumulate, and would it be accessible to clean out with the pump disconnected?

Regarding isolators, both hot and cold outlets have the usual flat head valves on the pipes, perhaps these are not full bore and are causing a restriction?

Suggestions welcome
 
Just moved house which has a traditional gravity fed hot water system,
did you operate the shower to ensure it works before moving in :?: did it work and supply constant temperature & flow ?

The previous occupants could have a technique of persuading the pumped shower to operate,or they may have not used the pumped shower who knows !. we dont know which pump or shower mixer you have and hopefully its all installed correctly,best get a plumber experienced with showers and pumps to inspect & advise.

combination gas boiler have their advantages and disadvantages. :mrgreen: best to have a system that suits the property & users demands not forgetting any future demands.

good luck :!:
 
No I didn't.

I have mentioned which pump it is, it is a Stuart Turner Showermate twin standard 1.8 bar. The shower mixer is a generic thermostatic mixer bar, no branding, like this:
ae235.jpg
 
Do these shed any light on the issue? The pipe runs look quite torturous which can't be helping
20180705_205507.jpg
20180705_205523.jpg
 
The pump runs when the shower is turned on, but makes no visible difference, at all. I only know it's running by the noise.
Only on site investigation will determine if the noise is actually both impellers rotating,the new photo supplied looks like a new pump on old pipework. Size and restrictions are apparent.The past users could have a technique to start the pump.

are also 15mm, and go up into the loft void and then across to the shower and back down the wall. The drop from the tank to the shower head is about a metre at best.
thats a worry,there could be other isolation valves on that run but hopefully an air release point or two to vent out trapped air.

I have mentioned which pump it is, it is a Stuart Turner Showermate twin standard 1.8 bar.
thanks for the detailed update,pumps vary. Tbh a negative head pump (with installation alterations) will rectify the no flow situation as long as the shower mixer is set up correctly.

Onsite investigation is recommended,although swapping parts out may work to a certain extent o_O.

happy plumbing :cautious:
 
Maybe this thread will help someone else one day.

There was an olive jammed between one impeller casing and the spindle. It fell out when I took the casings off to see inside.

Works perfectly now
 
Maybe this thread will help someone else one day.

There was an olive jammed between one impeller casing and the spindle. It fell out when I took the casings off to see inside.

Works perfectly now

That's why strainers are a good idea :)
 
It wasn't in the pump itself, it had somehow fallen into the gap between the motor housing and the impeller casing, although I didn't see it til I took the casing off. I probably would have had to anyway to free it.

Oddly, there are built in strainers on the outlets of the pump. Wouldn't it make sense for these to be on the inlets?
 
It's also very lucky the motor didn't burn out/catch fire while it was trying to spin
 

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