Only 6yrs old, it occasionally just vibrated,as though the impeller was just rattling, not rotating silently and the hot water sometimes took ages to arrive. I thought the pump had failed, but after the plumber replaced it, we unscrewed the pump body from its base. A tiny white plastic grommet appeared. This had clearly been bumping around against the central inlet of the impeller, which just floats on a central spindle and rotates magnetically, easily jammed by a small foreign body in the hot water 'ringmain'. So I have needlessly been charged around £150 for a new pump! Just spinning off the body would have revealed the problem. (I did try, but I didn't have wide enough pliers/wrenches). I hope this story is helpful - it was hopefully a learning experience for my plumber. The intermittent symptoms should have indicated there was probably nothing wrong with the pump which appears to have only one moving part! Goodness knows where the tiny white grommet, no bigger than a shirt button, came from.
Possible that the grommet came from the pump or damaged the pumps impeller so you cant fault the plumber for his diagnosis. If I hear a pump rattling its perfectly natural to assume it the bearings or impeller, whats not normal is to take one apart every time we hear a noise from one. The same applies to boiler fans.
Impossible. Adequate professional knowledge of the anatomy of this common pump precludes integral small grommets going astray. I agree a continuous rattle is suspicious of bearing failure but, as a competent domestic heating engineer/mechanic should know, this is a floating bearing with no moving parts apart from the impeller itself. The whole point of this story is to carefully note the symptomatology - this was an INTERMITTENT fault. With the right tools it would have been a simple matter to inspect it before removing it from the pipework.
Like they say hindsight is a wonderful tool, At the end of the day you called in a professional, he cured your problem for a reasonable price by doing exactlcy what 99% of us would have done. And now you turn to an internet forum complaining that you have been ripped off, bespite the fact that your problem was cured.
Dear Dave, this is a very odd and rather belligerent response. I am new here and only made the post to help others and to suggest a learning experience. If you seriously believe 99% would not rise above such a basic level of competence I despair for your 'us' community. And where is the complaint? I made no complaint. Indeed, I have not yet received the bill! The only inkling of the amount was his words 'would you believe these pumps cost around £180? ' At the time I had no reason to disbelieve him - after all, he purported to be a professional. However, a brief search online reveals the 15-14B PM is available from at least two suppliers for less than £150 inclusive of v.a.t. which is the sum I mentioned in the first post. I shall let you all know what transpires - who knows, perhaps he reads this!
Hi John. Welcome, and your original post was helpful, so thanks for that. As far as the whole episode is concerned, tho', it's a bit of both betwixt yersel' and oor Dave. But mostly on Dave's side... You had to open the old pump to find this white plastic thingy? So are you suggesting that every plumber called out to a noisy, rattling pump should do this as a matter of course? Of course not - most customers wouldn't be prepared to pay the extra half-hour of labour while a plumber stripped down a 6-year old rattling pump on the 'off-chance'. Because, what are the chances, eh? Wot's the likelihood of it being a wee plastic thingy? I have it on good authority - gawd almighty himself who, as well as creating the universe, is an awesome plumber - that there has only been ONE single recorded case in the history of mankind (that's around 250,000 years, don't you know) of there being a white plastic thingy caught in a CH pump. So, how 'lucky' were you! You further maintain that the ignorant waster of a plumber should have known it was a rattly object and not failed bearings 'cos it was an intermittent fault? Well, excoooooose meeee. I replaced the flue fan in my in-law's boiler due to failed bearings, and let me tell you that on some days it worked fine - tho' with a low rumble - and on t'other days it made a seriously worrying racket and even failed to rotate at all. That was intermittent, but what are the chances of it being caused by a white button? And you go on to accuse this hapless plumber of daylight robbery as he didn't scour t'interweb for the cheapest deal on the replacement pump. Well, excoooooose meeeeee again. I bought a set of Chinese import front discs for my C3 for £17 and took them to my local Citroen dealer and pulled the young apprentice aside with a "Fit these to my car post-haste, young man, and see that it takes you no longer than an hour. I expect this to cost me no more than £45." Guess what he said to me? Ok, that last bit didn't actually happen, but it is par for the course that tradespeeps charge pretty much the full retail price for parts. Y'know why? Because they are the ones who have to come out to replace it if it goes wrong - and customers don't expect to have to pay any more for that.
Hi DA, I enjoyed your amusing defence of 'oor Dave' but must refute your wild assertions. I have accused no-one of 'daylight robbery' ....yet. Your contradictory description of your flue bearing 'working fine-tho' with a low rumble' (if it was rumbling it clearly wasn't fine)reminded me of my old Wilson Wallflame oil boiler bearing which I eventually replaced after 20yrs; the rattle was temperature dependent, sometimes loud, sometimes not. Like your flue bearing, it was persistent and variable, not intermittent. Oh, and an unsatisfactory plumber did say I would have to replace the boiler! Incidentally, the CH pump worked perfectly when we bought the house and was still working perfectly over 30yrs later when we moved - as a Grundfos should. 6yrs is no time at all, especially when only on a few hours a day. Plumbers should know that. Your suggestion of 'half an hour's labour' to turn off the two stop-cocks either side of the pump and rotate a large brass ring three turns reveals what should be an embarrassing ignorance of the subject matter. You seem also to be ignorant of human development. Mankind has been around for a lot longer than you say, even if knowledge of pipework and hydraulics has not progressed much in some quarters since Roman times. In my experience the possibility of plumbing problems being caused by foreign material in the pipes is actually quite high and I am frankly amazed you don't appreciate this! If I took my lawn mower in for a carburettor fault I would not expect to have a replacement carburettor fitted when removing debris in the float chamber would be the cure.
Was the rattle from the pump continuous or only when the pump started up? Only reason that I'm asking is I've been called to a complaint today about a vibrating noise from the same said model that only occurs when the system first starts up and of course it was quite at the time of my visit!!
It would be continuous some days, almost completely silent normal running on others. Occasionally it would 'cure itself' when switched off then on again, but latterly wouldn't do this as presumably the offending foreign body would not float away from the impeller, jamming it against the body. As you probably know, the water enters the floating impeller centrally through some tiny holes about 2mm in diameter, then gets flung out centrifugally from its outer circumference. Just a thought - cavitation could be a cause; my new replacement pump rattled for a bit but has settled down to almost silent normal running now all the air which entered during its replacement has been somewhat explosively ejected from all the taps on the 'ringmain'!
No hard feelings - I'm just surprised spin-off in line filters aren't more widely used - like car oil filters. CH pumps failed regularly where I used to work; I thought it was possibly because of abrasive particles in the system. I remember the pipe to one groundfloor non-functioning radiator having to be replaced because it was clogged full of what looked like black iron filings!
Well John F - since you knew must have known what the issue was before you called in the plumber (from your posts) why didn't you strip the pump down and solve it yourself? No doubt because you don't know one end of a spanner from the other! You come on here to show off your knowledge (with the benefit of hindsight) and try and rubbish a clearly competent member of this forum (Dave does Gas). This is how it is John... When you get called to a problem such as yours, the most effective, least expensive and best quickest fix is to replace the part. This is not just plumbing, it is across all aspects of life today, get used to it. I'm not saying it is right, but it is what it is. And you got your problem fixed as Dave said. I'm just in having fixed a problem on a combi, did I try and find which wire on the hardness was open cct and fix it - nah - just replaced the harness - customer very happy. So please don't come on here trying to show off your knowledge - at the coal face it is slightly different.
Oh dear, another defensive poster! 'why didn't I strip the pump down' ? Didn't you either read or understand my first post? The answer is there if you read it carefully. I do hope you take a more careful history of your customers' symptoms and signs which at my 'coalface' are so important in reaching a diagnosis and embarking upon the right course of action. And I really do not understand what you mean by 'trying to show off my knowledge' , most of which is entirely unrelated to plumbing matters.
I've ordered a new pump for my said customer (£68.00). Do I just fit the pump and then charge the customer? Job done-profit made! Or do I strip the pump to see if I can find what may be causing the on/off vibration noise? If I find a white button inside of some other reason that might be the cause of the noise do I then put it back together without fitting the new one (my business is then £68.00 down). If the problem then reoccurs a few days later then it's a re-call for my business (I've lost even more money). At the end of the day plumbers have to make a profit somewhere down the line or they will simply go out of business.
I cannot advise you because I am not a plumber and I doubt if your pump in question is the 'same said model' because the Grundfos 15-14B costs much more than £68, unless you have a very cheap source, in which case I would be grateful for details. The whole point of my original post is to make the diagnosis from a careful history. It is a simple matter to 'strip down' this model by turning a brass ring three turns if you have the tools and strength and expertise to do so without damaging the pipes. Whether or not your business carries a small stock of commonly used items is not in question here - and your observation about making a profit applies to every self-employed tradesman/professional in the modern world!
Thanks, John - I'm ok now - I'm over it, and no hard feelings at all... Your post was useful in that it may give us peps a bit of 'pause' when we come across such an issue, but I think realistically it's not going to make a huge amount of difference for all the reasons stated above. It is such a rare occurrence, and to diagnose this extremely rare event any further would require a plumber doing something they wouldn't normally be expected to do. Yes these pumps last a long time, so 6 years isn't that much in the scheme of things - unless it's a system that's prone to sludge and all sorts flying through it (or buttons for that matter...) - but taken to its logical conclusion your proposal would have plumbers dismantling boiler flow switches (which are very likely to be faulty due to debris) or diverter valves (ditto) rather than replace them. Do you think, in practice, that the customers would prefer this? Trying to repair a part that's already had a good deal of its natural life used up?
It is such a rare occurrence, and to diagnose this extremely rare event any further would require a plumber doing something they wouldn't normally be expected to do. Do you think, in practice, that the customers would prefer this? Trying to repair a part that's already had a good deal of its natural life used up?[/QUOTE] For this customer it's a common occurrence accounting for 100% all callouts in the last five yrs - (one!) As always in today's disposable climate it's a balance between the cost of the time taken to repair/clean something and the cost of just using an expensive replacement part. E.g. our Hotpoint washing machine is developing the 'flashing lights' syndrome. Those with in depth knowledge and skill will cure it with a new capacitor costing less than a pound and a few minutes with a soldering iron. Those with less knowledge/fewer skills, or who don't care about the cost to their clients, will merely exchange the whole circuit board at much greater cost. And knowing this, some potential customers will just dispose of it and buy a new one. I'm weighing it up as I type......
Forums
Facebook
Twitter
You Tube
Instagram
Shop