No cold water to the bath

[ianatkin]

Hello all

I have no water (or the tiniest dribble) from my bath cold tap or my shower. Both are fed by a shower pump fed from the same branch off a T. The sink tap is fed off the other side of the T and there is plenty flow and pressure there. The section of pipe from the T through the pump to the common pipe to the tap/shower is shown below:

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• ianatkin
• 17 Oct 2012
• 1

Immediately after we moved in we had to have a radiator leak repaired. This meant turning off the mains water and, for unknown reasons, this stopped the cold supply to the bath/shower. I wasn't in when the plumber was here, but I'm told that in the 10 minutes he was here (charging us £95) he "massaged" the flexi hoses to/from the pump on the cold side and this got the flow back on.

Last week we had a water meter installed which again meant turning off the mains water and again stopped the cold flow to the bath/shower. Rather than pay another £95 for the privilege I decided to try and get it back on myself.

I assumed it was an airlock, either in the pump or the piping from the pump to the tap. I can't get mains water pressure on to the bath tap very easily (the tap is a bad shape and the threaded connection under the bath is in an inaccessible position), so I tried partially undoing the outlet connector on the cold side of the pump. Plenty water was released, with no result at the tap.

I then bought a wet & dry vacuum cleaner and tried putting that on the cold tap when fully open. It didn't help when the shower pump was off. Turning the pump on at the wall and opening the tap didn't activate the pump, but I found that, when the pump was on at the wall, applying suction not only turned the pump on but also produced a good flow of cold water, without the pump sounding at all strained. Except that... if I then turned the tap off, the pump stopped, then opening the tap again produced zero flow!

So basically what I have at the moment is a perfectly functional bath and shower that require a vacuum "starter" to be applied to the cold tap before I can use it!

I would be very grateful for any suggestions for my next move.

One thing I particularly don't understand is what the device is to the left of this pressure gauge reading zero - is it a pressure regulator and can it be adjusted? Somehow, having a gauge reading zero seems wrong!

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• ianatkin
• 17 Oct 2012
• 1

The system has a cold header tank in the loft, unsealed hot water cylinder and an old (>15 years) conventional gas boiler.

I will finish by saying that I only moved in here a month ago and have found numerous examples of cowboy workmanship so please don't blame me for the inaccessible plumbing, the undersize piping, the shower pump off a shared connection from the loft, etc etc!

Thanks
Ian

 

[Charnwood]

The thing with the gauge is a pressure reducing valve, made by Caleffi.
Is it on a hot or cold pipe?

I'm a little unsure about this joint:
View media item 51493Looks like a 22mm PRV with a reducing set to 15mm, then the pipe has been altered to 22mm. Looks odd, botched, even. In fact, it looks like a botch all round. Too much loose pipework for my liking! The joints the other side of the PRV look suss, too! My 5 year old granddaughter could do no worse.

 

[Dan Robinson]

The whole thing looks like an abortion. You need a trustworthy plumber there for an agreed rate to suss out and explain what the last knob jockey thought he was going to achieve..

My thoughts are - based in the non existent info, you have mains cold water and gravity hot , boosted by the pump.

The gauge or reducing valve is either faulty or not set correctly.

We have had to do similar on one or two occasions, but with the express understanding that it is a bodge and not intended as a permanent solution.

 

[ianatkin]

Thanks for your replies. I had assumed (you know what they say about assumptions) that it was a gravity cold feed off the loft tank but now you've pointed it out it's clear that they've taken a mains supply and put a pressure reducing valve on it. Even bodgier than I realised.

The pressure reducing valve is indeed on the cold side.

The bathroom had apparently been recently replaced before we moved in and, without the time or money to rip it all out I'm going to have to live with it until such a time as one of the many dodgy joints leak and I *have* to take it out.

Thanks again
Ian

 

[Charnwood]

The PRV has probably been fitted to try to replicate/equalise the cold pressure to that supplied by the pump.

That model (from the 533 range) works on dynamic pressure only.
Being a mere counter boy I am not certain, but the gauge not registering might have something to do with that, if there's no water passing through. (Static pressure?)

Under the plastic cap there's an adjuster. It is adjustable between 1 bar and 6 bar.

 

[ianatkin]

The PRV has probably been fitted to try to replicate/equalise the cold pressure to that supplied by the pump.

That model (from the 533 range) works on dynamic pressure only.
Being a mere counter boy I am not certain, but the gauge not registering might have something to do with that, if there's no water passing through. (Static pressure?)

Under the plastic cap there's an adjuster. It is adjustable between 1 bar and 6 bar.

Good to know, thanks

Ian

 

[Charnwood]

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• Charnwood
• 18 Oct 2012
• 9