Post by rgirling on Dec 16th, 2015, 5:23pm
The shower pump is a low-voltage integral in an Aqualisa Aquastream shower. It shuts off with the flow.
The vessel is a red Zilmet 4 bar - see pictures below (which also show the layout):
Ray
| Ask The Trades | |
|
https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl
DIY Forum >> Plumbing Questions >> A strange situation ... https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1446629973 Message started by rgirling on Nov 4th, 2015, 9:39am |
|
|
Title: A strange situation ... Post by rgirling on Nov 4th, 2015, 9:39am I have a conventional household water system, in that it consists of a storage tank in the loft, an indirect cylinder one floor below and hot and cold taps on the first and ground floors. The central heating is pressurised and separate, but I'm sure that's not relevant. A while back a noise started, something like water hammer, but different as it would occur every 40 seconds or so and only last for between 2 and 10 seconds. It sounds like a brief but soft engine-revved noise, as opposed to the normal "done-donk-donk" noise of hammer I've heard in the past. Feeling the pipes running through the airing cupboard, the vibration comes from the pipe that supplies cold water to the storage tank. The rising main stopcock is on the ground floor and there is another mains-pressure supply reaching the kitchen sink. I suppose that tees off the other riser. All other supplies are fed from the storage tank, as far as I can tell. Now for the strange part: the noise can be stopped immediately by opening (even very slightly) any of the tank-fed cold water taps - NOT the hot taps, just the cold ones. The only way I've found to eliminate the noise is to crack open one of the tank-fed cold taps, but I cannot understand why this is, as there is little pressure in the gravity-fed supply, compared to the mains-fed tap. I've tried replacing the storage tank ball-valve (three different types), making sure that the connection to the ballcock is as rigid as possible, putting in an air trap at the top of the tank cold supply (teeing a closed-end pipe above the bend to the ball valve) and I thought about replacing the main stop cock, until - when fully shut off, the noise continued! How is that possible? I don't have that much hair left to pull out, but this is getting ridiculous. Where should I look next, please? Ray |
|
Title: Re: A strange situation ... Post by thescruff on Nov 4th, 2015, 10:27am Can you make the noise happen. ?. The air pipe is about the worse thing you could do as it will cause the water to bounce, get a proper shock arrester if anything |
|
Title: Re: A strange situation ... Post by Headrush on Nov 4th, 2015, 11:00am Only thing I can think of would be the WC inlet valve, it fits with the profile of your description. Quick and cheap to replace and will eliminate another suspect.. |
|
Title: Re: A strange situation ... Post by thescruff on Nov 4th, 2015, 9:50pm Headrush wrote on Nov 4th, 2015, 11:00am:
One type of ball valve is common to make groaning loud noises when the diaphragm is worn |
|
Title: Re: A strange situation ... Post by rgirling on Nov 6th, 2015, 10:52am The noise happens if none of the CW tank-fed taps are open. Simply cracking open any of the CW tank-fed taps stops the noise at once. I'll replace the pipe with an arrestor ASAP. Thanks to all who responded, much appreciated! Ray |
|
Title: Re: A strange situation ... Post by thescruff on Nov 6th, 2015, 10:35pm I would sooner you changed the ballvalve to a brass equilibrium valve first. You should also check the WC ballvalves |
|
Title: Re: A strange situation ... Post by rgirling on Nov 12th, 2015, 3:25pm OK, done that. Do I need to pressurise the arrestor (bicycle valve), or will it sort itself out? It's fitted in place of the previous air pipe on a short 15mm stub. Ray |
|
Title: Re: A strange situation ... Post by thescruff on Nov 13th, 2015, 12:19am The pre-charge pressure is marked on the vessel and usually pre-set |
|
Title: Re: A strange situation ... Post by rgirling on Nov 14th, 2015, 11:37pm I guess what I'm asking is how does it work and/or how do I know it's working? I suppose it contains a diaphragm which gives some leeway to sudden increases in water pressure, but do I need to check the pressure at the Schrader valve or not? If so, when (water running, still, etc.), and is an accurate tyre pressure gauge good enough? Sorry, that's more than one question! Ray |
|
Title: Re: A strange situation ... Post by thescruff on Nov 15th, 2015, 8:22pm I wouldn't touch it unless there's a problem a few years down the road. |
|
Title: Re: A strange situation ... Post by rgirling on Dec 4th, 2015, 12:31pm Well, I've felt a few in my time, but I feel like a very big one at the moment! I now discover that - far from being the cold supply pipe to the tank that is vibrating, it's the cold water supply pipe FROM the tank that is at the root of the problem. It seems that the pipe is "thrumming" when the storage tank is full. Any release of cold water, however small, at any tank-supplied cold tap, halts it at once, but it re-appears when the tank is full again. I thought that it might be the level of water in the tank was too high, creating too much pressure in the supply, so I reduced the level by adjusting the float downwards, but no luck. I feel that it may be caused by vibration where the pipes pass through joists below the floors. I can get to most of these but - before I do - may I seek your indulgence with another question, please? If you think there is no other cure, would it be OK to use expanding foam to insulate the pipework from the joist timbers, or is there a better way? So sorry to be such a pain. If only I'd have counted the emerging pipes correctly in the first place, I wouldn't feel such a t***! ::) Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 4th, 2015, 9:15pm Ray can you post a pic shower where the ballvalve connects to the storage tank inside and out please, include the ballvalve as well |
|
Title: Re: A strange situation ... Post by rgirling on Dec 5th, 2015, 9:49am I could, but I'm back on my FluidMaster valve, as the equilibrium brass one was too noisy and made no difference anyway. It's not the CW supply pipe to the tank that's thrumming, it's the cold supply from the tank. The noise can be halted immediately by opening any non-mains-fed cold tap, returning immediately when closed. Leaving such a cold tap cracked open by the slightest amount is a cure, but not an environmentally-friendly one! When the pressure is released by opening a tap, the vibration can be felt in the tap itself and I've made sure that the vibration is only coming from the "down" pipe from the tank, not the supply, nor is it transmitted by contact with the rising main to the tank. Thanks, BTW, for all the help. Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 5th, 2015, 10:11am Ok perhaps a little plumber lesson. ;D As the storage tank fills the ballvalve slowly closes, and its the last half a pint shall we say that causes the noise, therefor when you run any cold tap the ball drops slightly and the noise stops. Low pressure tank fed supplies do not make vibrations, unless there's a pump or anything mechanical that can cause it. The above is why I want the pics to see whether anything is noticeably wrong. It may be a loose washer/jumper in the stopcock or several other problems like unfixed pipes but at the moment it points to the storage tank. You can easily proof my point by pressing the ball down next time it makes a noise. There's is also a chance it may be your neighbour, so we should explore that posiblity as well, if it's a shared main, so some back ground info please. Have you checked all the outlets especially the wc valves. Is the cylinder fed from the tank or mains. Is there an expansion vessel anywhere near the pipes. |
|
Title: Re: A strange situation ... Post by rgirling on Dec 6th, 2015, 12:21pm Thanks for the comprehensive reply - I do appreciate the help. I'll answer in the order asked: The main is not shared. All valves have been renewed, including the three toilet valves. The cylinder is tank fed. There is an expansion vessel for the pumped CH system, but nowhere near the pipes in question. The noise does not occur as the tank is completing being filled. The tank valve, when closed, does not allow any by-pass, as it's new. Three different types of tank valve have been tried, resulting in no difference whatsoever. I accept that - when cold water is used from a tank-fed tap - this will eventually cause the tank level to drop, opening the valve and replenishing the tank. This, of course, also applies to the tank-fed hot taps, but opening those has no effect on the noise whatsoever. I have felt the vibration in the cold feed coming from the tank. There is no vibration from the mains feed to the tank at any stage. The vibration can be also felt in the tank-fed cold taps as they are released by the slightest fraction and before this stops the vibration. The vibration re-occurs as the tap is closed. Running the tap sometimes cures the vibration for different lengths of time. I cannot imagine that letting a couple of drops of water per second will cause an instant drop in the level of the storage tank, as it takes quite a while for the tank valve to react to a drop in level (the release of the tank valve can be heard as the valve opens (after washing or a toilet flush, for example) and no such noise occurs when cracking open the cold tank-fed taps by such a tiny amount. Photographs will follow, once the noise re-occurs and I've had a chance to depress the tank valve as you suggest. The noise is not constant, occurs randomly - mostly after a long period of tank inactivity - but is unbelievably annoying, as you can imagine! Ray |
|
Title: Re: A strange situation ... UPDATE Post by rgirling on Dec 8th, 2015, 10:30am Update When the vibration occurred again, I went to the loft and depressed the float. Although water came in, the vibration was unaffected. I have confirmed that it is coming from the cold supply that emerges from the base of the tank and I have taken pictures as requested. To save forum space, I've written a page to host the pictures at http://www.raygirling.co.uk/loftpics.htm I hope the pictures are good enough, if not I'll take others with a SLR instead of a mobile. Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 8th, 2015, 6:01pm Ok quicly because I have to go referee. Where does that pipe go and is it connected to another pipe ?. Looking at the pics my original suggestions haven't changed. The mains feed is swinging about in the breeze, and still the most likely problem. I'm sure if we stick with it we'll track it down eventually |
|
Title: Re: A strange situation ... Post by rgirling on Dec 9th, 2015, 10:25am It is the cold supply to the house, excepting the kitchen sink, which is mains-fed cold. Therefore it supplies all cold taps and toilets, passing down through the airing cupboard and then beneath the floor, where it tees off to its various outlets. There is no vibration in, or caused by, the mains feed. It may be "swinging about in the breeze" but the (new) tank valve is not the cause of the vibration - I thought that I had established that yesterday by depressing the valve as suggested, which made no difference. You may notice that there is an isolating lever on the mains feed. The vibration continues with that closed. The vibration continues even with the mains shut off (at the stop cock or at the meter), which seems to me to rule out any problem with the jumper (if any) in the stop cock. For my money, this seems to support the fact that the vibration is caused by something within the tank-fed cold water system, but you already say that this is not possible. I can only re-iterate that this is where the vibration is coming from. Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 9th, 2015, 4:08pm Lets reword it slightly. I've never seen or heard of a tank cold supply vibrating, other than from an external source in the 57 years since I started in the trade. If the tank cold feed is vibrating then something is causing it, so we need to look at the pipe and fittings. How far can you trace it. Is there to your knowledge any fittings that maybe unusual. Is there a check valve on the pipe anywhere. Is the water in the tank clean and no signs of a backflow. Is the pipe the cold supply to all the outlets or the cylinder. How far from Bath are you. |
|
Title: Re: A strange situation ... Post by rgirling on Dec 9th, 2015, 9:10pm Could you clarify what a check valve is, please? The pipe feeds the cold taps, toilets and bath. The indirect has its own feed. There is probably 10 metres of pipe to the bath. I can trace most of the upper floor, hardly any of the downstairs, due to layout of the house. Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 10th, 2015, 10:23am http://www.screwfix.com/search?search=non+return+valve Some are built in (quality mixer taps) for example, others are separate |
|
Title: Re: A strange situation ... Post by Lurch on Dec 10th, 2015, 6:46pm I had a similar situation recently, but the vibrating was happening when the taps were on. It appeared that there was air being drawn in through the vent pipe so I lifted the vent up higher and that solved it. Could well be that air is being drawn in when your taps are on and the vibrating is the air trying to work its way back up again. Not sure how or why as I wouldn't expect there to be a vent on the cold feeds from the tank, but who knows what happens over the years under floorboards and what may be cross connected where. Could also be a dead leg somewhere full of air causing the same effect. Does the vibrating ever stop of its own accord? |
|
Title: Re: A strange situation ... Post by rgirling on Dec 10th, 2015, 8:42pm I believe that it does sometimes stop of its own accord, but - to be honest - I crack open a tank-fed cold tap to stop the noise, as it's so annoying. I'm not saying it's very loud, but it's insistent and the vibration is worrying in case it affects joints in the system. Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 11th, 2015, 9:05am When you crack open a cold tap to stop the noise, how long before the noise comes back. |
|
Title: Re: A strange situation ... Post by rgirling on Dec 11th, 2015, 1:01pm Immediately I close it, most of the time, especially at night, which is why I leave one cracked open. The noise also stops if I depress any of the toilet ball cocks, but it would as they're off the same supply. Once water is drawn from the tank (and, therefore, lowering the level, I suppose), the noise goes away and often for several hours, but rarely more than a day, once all taps are closed. There's a gate valve on the downpipes for the cold supply from the tank, but shutting that makes no difference either (although I accept they're notorious for letting by). Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 13th, 2015, 3:46pm Can you record the noise and post on your blog |
|
Title: Re: A strange situation ... Post by rgirling on Dec 13th, 2015, 5:00pm I'll do my best! |
|
Title: Re: A strange situation ... Post by rgirling on Dec 14th, 2015, 8:47pm I've made a short clip and up-loaded it to www.raygirling.com/loftpics as before. It works OK in Firefox and Opera, but Microsoft Edge and Safari don't like it. Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 14th, 2015, 10:55pm I don't like Microsoft edge anyway. That sounds like and external pumo type vibration. Can we go down a floor and post some pics of the cylinder connections not too close the more you can get in, in one pic the better. How big is the system, Is there a secondary circuit on the hot water. Post as much details as you about the system relvant or not. |
|
Title: Re: A strange situation ... Post by rgirling on Dec 15th, 2015, 11:55am I've taken pictures and posted them, as requested. Ray |
|
Title: Re: A strange situation ... Post by Lurch on Dec 15th, 2015, 11:43pm If it goes all night and it is a pump causing it then something is adrift as there wouldn't usually be anything running 24/7. Can you turn off the power to anything to narrow it down, heating circuit/boiler/shower pumps etc? |
|
Title: Re: A strange situation ... Post by rgirling on Dec 16th, 2015, 12:55am The CH is fully pumped, the shower has its own integral pump and that's it as far as pumps go. The CH pump and MVs are in the airing cupboard. Next time it happens, I'll try switching off the CH system entirely. Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 16th, 2015, 9:14am Don't think its the heating pump as it wouldn't stop when you open a tap, still worth checking though, it could be the shower pump not turning off and maybe running dry or static. What colour is the expansion vessel and approx age ?? |
|
Title: Re: A strange situation ... Post by rgirling on Dec 16th, 2015, 5:23pm The shower pump is a low-voltage integral in an Aqualisa Aquastream shower. It shuts off with the flow. The vessel is a red Zilmet 4 bar - see pictures below (which also show the layout): Ray |
|
Title: Re: A strange situation ... Post by Headrush on Dec 17th, 2015, 1:50pm I know this is a long shot but have you tried experimenting with reduced tank head, even completely empty and then adding head an inch or so at a time (use the nearest isolation valve or tie up the ballvalve) and deduce at what height of head the vibration problem occurs. I'm guessing with an empty tank the vibration should not occur and we can possibly narrow it down to a head pressure thing. There may also be check valves in the shower supplies, maybe try and isolate those too. I have to admit this is a very curious problem, and as Scruff has said, in all his years it's never happened on his watch.. :-? |
|
Title: Re: A strange situation ... Post by rgirling on Dec 17th, 2015, 2:23pm i tried reducing the level in the header tank (see post number 11), so it wouldn't hurt to lower it a bit more, I guess. Could you expand on "head pressure thing" for me? Ray |
|
Title: Re: A strange situation ... Post by Lurch on Dec 17th, 2015, 3:38pm The "head pressure thing" is the pressure created by the water in the tank, the head is the distance above the outlet that the top of the water is so lowering the water level in the tank will reduce the head/pressure. |
|
Title: Re: A strange situation ... Post by rgirling on Dec 17th, 2015, 8:28pm OK, thanks - more or less what I thought, but how does that cause a vibration? Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 18th, 2015, 11:06am Unlikely that it will but we're clutching at straws so anything is worth a try. Did you isolate the power shower electrically. My take on it, is still external from the tank so switching anything electric off should stop it eventually. Expansion tanks can vibrate but yours is for the heating and there shouldn't be a connection. Sounds like a pump-or motor as your original post and that is where I would concentrate, the noise is too fast and regular to be much else. |
|
Title: Re: A strange situation ... Post by rgirling on Dec 18th, 2015, 11:28pm As I said earlier, the shower has a built-in low-voltage pump that switches on once the water flow reaches a certain volume, so whilst it is possible to run the water (gently) without the pump kicking in, it's not possible for the pump to run without water - anyway, I'd hear it. It has got an isolating switch, so I will isolate it next time the noise kicks in. The only other pump in the house is the CH pump, mounted in the airing cupboard, as shown in earlier photos. I can hear that clearly when it runs too, but the noise occurs at any time of the day or night when it's not running. I'll switch that off too when I hear the noise again. Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 19th, 2015, 10:38am I would probably go mad and throw the main switch next time it makes a racket |
|
Title: Re: A strange situation ... Post by rgirling on Dec 19th, 2015, 2:35pm I was thinking that - it would be a definitive answer, either way! :) |
|
Title: Re: A strange situation ... Post by rgirling on Dec 21st, 2015, 8:56am Update: I isolated the shower - made no difference, but not surprising because, as I said earlier, it has separate balanced supplies. Next task - throw the mains switch! Ray |
|
Title: Re: A strange situation ... Post by rgirling on Dec 23rd, 2015, 12:05pm Further update: Threw the mains switch - no difference. I then fully turned off the gate valve on the down-pipe from the storage tank and the noise stopped. I think this sort of proves that the noise is related to the head of water, so I'll turn that down as low as I can go and see what happens. Merry Christmas and a Happy New Year! Ray |
|
Title: Re: A strange situation ... Post by thescruff on Dec 31st, 2015, 11:18pm Sorry Ray, not possible unless you have running water and even then unlikely. What does the valve feed/turn off. What size pipe is the cold feed. Is the pipe hot/warm below the valve. And a very happy and Prosperous new year to you |
|
Title: Re: A strange situation ... Post by woodsmith on Jan 5th, 2016, 9:00am Scruff, what about fitting a mini Rester to the cold pipe where it leaves the tank to feed the house, do you think that may make a difference? http://www.toolstation.com/shop/p85345 |
|
Title: Re: A strange situation ... Post by thescruff on Jan 5th, 2016, 9:18am woodsmith wrote on Jan 5th, 2016, 9:00am:
Dont think it will make any difference Woodsmith. Still thinking about the problem so talking out loud to myself. Gate valves and checkvalves can rattle, but, you need running water, or perhaps better circulating water. Turning the gate valve off has stopped the noise which kind of proves the theory but Ray has also said opening any tap also stops the noise. It's possible to get parastatic circulation in a pipe but it wouldn't be as regular as the recording, same applies if the coil in the cylinder has gone. I did ask question but not answered. Clutching at straws I would probably change the gate valve |
|
Title: Re: A strange situation ... Post by woodsmith on Jan 5th, 2016, 9:41am Could the shower pump have a flow valve fitted in the supply which is oscillating, perhaps it would be worth turning off the isolating valves feeding it? |
|
Title: Re: A strange situation ... Post by thescruff on Jan 5th, 2016, 11:48pm Probably the only way to track the problem Woodsmith, take each part out of the equation. A listening stick may help to get you nearer to the noise. The noise is too regular to be water hammer and in any case you need running water for that. As per Rays opening post it sounds like a motor or in my opinion a pump |
|
Title: Re: A strange situation ... Post by rgirling on Jan 15th, 2016, 12:40pm thescruff wrote on Dec 31st, 2015, 11:18pm:
The valve shuts off the cold supply from the storage tank and definitely stops the noise when fully closed. The pipe is 22mm. It's a cold feed, so no - not warm anywhere. I've got the storage tank supply valve set at its lowest setting which has reduced the head of water, but not by much. Over the last couple of weeks, the noise has been triggered two or three times by my wife walking into her bathroom. No, she's slim and fit, it's not a load problem! However, it seems that some movement or flexing of the floor sets the noise off, so I'm now investigating the mounting clips, etc. The trouble is that - when the noise starts - by the time I've got beneath the floor, it's stopped again. I can't find what or where unless it's making the noise and it's almost impossible now to make it start. Bugger! Ray |
|
Title: Re: A strange situation ... Post by thescruff on Jan 15th, 2016, 4:18pm I think you'd be better investigating as much as you can under the floor and hidden to see what you can find. Turning the gate valve down will reduce the flow not the head |
|
Title: Re: A strange situation ... Post by rgirling on Jan 15th, 2016, 4:38pm thescruff wrote on Jan 15th, 2016, 4:18pm:
Yes, quite so. But adjusting the CW inlet valve (ballcock) to its lowest setting has reduced the head a little, which is what I said. Appreciate all the suggestions! Ray |
|
Title: Re: A strange situation ... Post by rgirling on Apr 21st, 2016, 2:08pm SOLVED! I found that the WC in my wife's bathroom was letting water by (into the pan) and had been doing for some time! I replaced the Multiquik flush and the noise has never occurred since. I can only think that this was sometimes causing the shut-off valve in the toilet to "bounce" or oscillate. Anyway, we're finally free of the problem and offer many thanks to all those who helped and made suggestions. Ray (and sheepish grin from wife Jean) |
|
Title: Re: A strange situation ... Post by thescruff on Apr 22nd, 2016, 8:00am Thanks for the update Ray, good to know I haven't gone completely doolaly, I think that was about my 2nd post last year. ;D |
|
Title: Re: A strange situation ... Post by londonman on Apr 22nd, 2016, 10:14pm rgirling wrote on Apr 21st, 2016, 2:08pm:
There's posh!! How are you doing, Ray...still driving those lovely motors about the place ;) |
|
Title: Re: A strange situation ... Post by rgirling on Apr 22nd, 2016, 11:38pm Less now than previously, but still the occasional Phantom, Bentley Arnage and Flying Spur, Maybach, etc. One of my regulars was in the '66 team and as it's the 50th. anniversary this year, I expect there'll be a bit of running about to come. ;D |
|
Title: Re: A strange situation ... Post by rgirling on Apr 26th, 2016, 4:39pm If only I'd have realised that the diaphragm you were referring to was the one that let the water into the pan and NOT the one in the supply valve, I'd have saved everyone a lot of trouble! :) |
|
Title: Re: A strange situation ... Post by thescruff on Apr 26th, 2016, 8:06pm I'm surprised you couldn't hear or feel it in that cistern, or are you not allowed in the wifes bathroom. ;) |
|
Title: Re: A strange situation ... Post by rgirling on Apr 27th, 2016, 12:49pm Actually, there was no noise involved, as the leaking water slid down the back of the pan like a well-oiled racing snake. I wouldn't have dreamed of polluting her bathroom with either a number one or (God forbid) a number two, so I was unaware of the leak as I didn't lift the lid! Lesson learned - I'll do a proper recce in the future! |
|
Ask The Trades » Powered by YaBB 2.3! YaBB © 2000-2008. All Rights Reserved. |