Plumbing q - noise from either shower pump or pipes?

[CatAndHisKit]

I had an ongoing issue with the main shower (over bath) where the water didn't heat properly, but found tha it helped to run the bath cold tap when shower is on as then it's hotter.

Since then the shower seemed to 'run dry ' towards the end of its runand the hot water came out for a bit when it started making noises - like revving ir trying to suck in water from the supply pipe but it wasn't coming, at which point I always turned it off. Sorry but not easy to decsribe very clearly.

Today for the 1st time, this started affecting the bath taps. When I open either hot or cold bath tap and let the water run for a few seconds / a minute, then close the tap, that revving noise (intermitten, frequent) goes on. Agagin it's as if a pump or whatever tries to get filled with water but instead the air is coming. If I run gthe tap for a bit again, it eventually stops revving. It's revving not when the tap is running but straight after.
I'm worried it's some sort of airblock in the pipes. I thought it was the shower valve (had a thread about it) or the pump but why would it be conneted to bath taps?! Really worried it's something serious with supply from hot water tank or the pipes.

[CatAndHisKit]

*mains shower

[CatAndHisKit]

Just to clarify - 'since then' means sinmce the shower temperature issue started, not since I was opening the cold bath tap to make it hotter (that was very recent). Also it's was hot enough on its own in hte recent hot weather, didn't need to open bath tap - but the air issues always happens by the end of using it.

[Geppili]

Have you got a header tank? It sounds like the valve is worn.

[cantstopsinginglittlebabybum]

Sounds like air hammer. Put the pressure up in your boiler.

[CatAndHisKit]

Geppili I have but it's on the floor above.

cant thanks, do you mean air in the system?. How much should I put pressure up - and would that affetc anything else?

[PigletJohn]

have you got a hot water cylinder? What colour?

[CatAndHisKit]

it's a coppery colour, PJ.

[Geppili]

It might be your header tank filling valve. We had this and even tho our in in attic it produced huge noises.

[PigletJohn]

then pressure in your boiler (if any) will not be relevant.

Your pump might be sucking the water so fast that it draws air into the pipes.

Fill a bucket at the shower, time it, calculate how many litres per minute it delivers.

After a long shower, look in the cold-water tank in the loft or on top of the cylinder to see how full it is.

Some photos of your pipework, pump, cylinder and cold-water tank will help.

[CatAndHisKit]

thank you! will try that tomorrow.

[CatAndHisKit]

PJ, do you know why a mains shower might have stopped heating up properly? It does eventually heat up after using the handheld shower or just runnin hot bath tap for a long while, but that of course takes a lot of hot water so then the (pumped) shower lasts very little as it's fast.
Is it a faulty shower valve as people suggested on my other thread or smth else? It seems to be hot enough in hot weather though.

[PigletJohn]

Do you mean an electric shower?

Put your thumb over the spout of the hot bath tap and turn it on. Can you hold back the flow by pressing with your thumb?

Now try the cold.

[user1471528245]

If the temperature of the shower is affected by running the bath you shower is being fed by your hot water system so the boiler is providing the heat or a hot water cylinder, the sounds you are hearing is potentially from an external pump Especially if you can hear it clearly assuming your boiler is no where near, I would suspect it’s failing or is drawing air, if you have no pump this could be the shower valve itself (although you don’t normally get noise) they can fail to send hot water when they get limescale build up

[CatAndHisKit]

It's a mains shower, PJ.

user the boiler is exactly near there, behind same door as the shower fitting. The shower has a pump. Someone siggested it may be limescale in valve previously - so that's interesting. Do you think gthe valve can be decsaled (by a plumber)? Replacement valve very expensive (Mira) , shower is only 6yrs old.

[CatAndHisKit]

user do you mean the shower pump or some other external one? Is it easier/cheaper to replace the shower pump than the valve (hundreds)?

[PigletJohn]

I don't know what you mean by the term "mains shower."

Please explain.

[CatAndHisKit]

It's not electric, plumbed in (and with a pump in this case). That's the term estate agents use

[PigletJohn]

But it is fed from a copper-coloured (vented) cylinder with a pump so not the watermain.

[CatAndHisKit]

ah thanks - the subtleties of plumbing. Btw I don't think I can stop the bath taps flow with my thumb.

[PigletJohn]

cold?

maybe not. Try.

or hot?

I bet you can.

[user1471528245]

If it’s limescale you can do it yourself if handy with a spanner, You don’t even need to turn the water off, normally on the mixer end There will be a plate, might be push fit or have a tiny screw remove this and you can then unscrew the mixer valve with a spanner, drop it in some white vinegar for an hour to remove the limescale, there are plenty of videos on YouTube on how to do it, done mine several times (hard water area) you def don’t need to change the valve they pretty much last the lifetime of a shower