Apologies in advance for my complete ignorance in all matters plumbing, which will become apparent below, and for the length of this tale of woe:

Background: House, hot water is old school boiler and cylinder, there’s a tank of some sort above it in the loft. A few years ago we had the bathroom done and a shower put in. The plumbers who did this turned out not to be the best, but it got done, however, the shower wouldn’t give us more than a trickle of hot water so, on the advice of said dodgy plumbers, but not installed by them, we had a negative head pump installed next to the hot water cylinder.

All good. Turn on hot taps or the shower and hot water cascades out, lovely hot showers, job’s a good ‘un.

Now and again, if the power went off when the water was running, the pump was a bit glitchy to come back to life afterwards – you’d turn on a hot tap and no pumpy. Swearing at it, and turning all the taps on, especially including the one downstairs in the kitchen, and it would generally come to life again. All good.

So, about a month ago, we had a dribbling mixer tap on our bathroom basin so called a plumber. Plumber comes, shuts off main stop valve for the cold supply, finds the valve he would have used to shut off the hot supply is goosed, so has to drain hot water tank. Replaces tap. Turns everything back on. No pumpy. Faffs about for several hours (really) forcing water through pipes in the loft to clear airlocks or whatever, eventually, pumpy pumpy again, hurray!

But no, after he’s gone and the wife’s paid him (I wasn’t there at this point) we discover that things aren’t quite right. Symptoms as follows:

1) Pump coming on when the toilet’s been flushed and the cistern is re-filling. Pump is only on the hot supply so that ain’t right. HOWEVER, at some point after a week or two, this stops happening.

2) Pump not coming on when the shower (only) is switched on. However, if you turn on the bath (bath and shower activated by combined mixer panel thingy halfway up the wall) the pump comes on. Then if you turn on the shower, the pump is still on, and if you turn off the bath, leaving just the shower on, the pump stays on. So pump on with shower is fine, but pump won’t come on by just the shower being switched on.

Even when the pump’s on for the shower, it’s not as hot as before – either the mixer’s got knackered, or the hot pressure’s down? Bath supply (via the same mixer thing) is still toasty hot, as is hot from other taps.

This is where it starts getting really annoying. I phone plumber back and there follows four weeks of bull and avoidance – promises to come out and have a look at it not kept, promises to return calls not kept, basically the guy gives me the runaround for a month, but then realises I’m not going to stop calling, says he’s coming round today, to deal with what he says are airlock issues.

And that’s where it gets a million times more annoying. In anticipation of today’s promised visit, I decide to have a bit of a go at it myself last night, given that it’s just an airlock problem, what’s the worst that can happen? I’ll tell you – after a few random goes at “turn on the taps and see what happens” I decided to switch the pump off just to see what came out of where. Nothing much to excite or surprise, but then I turned the pump back on and guess what? No pumpy! Not from any tap, mixer or shower. Nothing. Pump just sits there, silently goading me with complete inactivity. Bastard thing.

So, after only one chase-up call, dodgy plumber finally comes to call today. First of all says it’s airlock, but then I explain about the pump not activating. Despite me repeatedly pointing out that the pump was working fine until yesterday, everything is, according to him, because the pump’s knackered.

Either a new pump, or rip out the boiler and replace with combi are his recommendations. Not that there’s a chance he’d get the job even if this is true.

So, before the tap job was done, everything worked fine, hot water pumping out of every orifice it should have at a great rate of knots, afterwards, not really happening, now pump not doing anything (but was until yesterday when I turned it off) – WTF is going on and what do I need to do to get back to where I was a month ago?

Thanks in advance and, once again, apologies for being clueless in these matters.

EDIT: “John The Plumber” in Leeds – Avoid – not good at returning calls, turning up when he says he will and not f’ing up your hot water

Pump just sits there, silently goading me with complete inactivity. Bastard thing.

It’s probably old and starting to get intermittent. They’re quite easy to swap out.

Ours starting doing this (not starting some days and then being fine for a week on end) so I swapped it out a few weeks back…

Old one:

[url=https://flic.kr/p/nRWqNd]Old pump: Grundfos UPE 2000[/url] by brf, on Flickr

New one:

[url=https://flic.kr/p/nBukZU]New Pump: Grundfos UPS2[/url] by brf, on Flickr

NB New one was upside down in that photo as they’d changed the pump direction, so I had to swap it round……

Thanks FF, although

They’re quite easy to swap out.

really, really overestimates my competency in such matters. If I could just find a plumber who isn’t an equally clueless dishonest git, I’d maybe get them to try a new pump.

negative head content.

Describes my sex life in three words.

Possibly you have something like a booster pump fitted ?

like this :

http://www.plumbnation.co.uk/site/grundfos-upa-15-90-home-booster-pump-59539509/

It does have a flow switch – which could give problems

Try the auto/on/off switches ?

Check the wiring – or have it checked.

Or replace it / have it done – get the new pump yourself to save time.

really, really overestimates my competency in such matters.

Got a mate into DIY, offer him a few pints?

You can buy a pump at Screwfix. Have a look for vids online but process is this:

Work out which way pump is pumping (there will an arrow on the existing body). Write this down.

1. Switch off MAINS
2. Disconnect pump wires (taking a photo of where they go before) – tools needed 1x screwdriver
3. Screw shut both lock valves below and above the existing pump : tool needed 1x adjustable spanner (if they don’t have a handle wheel thing on them)
4. Put old towel on floor beneath the pump
5. Undo the pump connectors (this needs a large spanner, which you might have to buy from Screwfix)
6. Take out old pump, about 80ml of murky water will spill onto towel
7. Put new pump in the space old pump was in. There are two rubber washers, one at each end you need to make sure are in place, these keep the water in.
8. Screw new pump connectors back up (no need to be super tight, the rubber washers create the seal)
9. Double check the new pump is in the right way, new arrow points same way as old arrow
10. Open both lock valves slowly and check for leaks, if it leaks do them back up and tighten up the pump connectors or check that the rubber O ring / washer is in there
11. With Mains still switched off, connect new pump wires back where old pumps wires went.
12. Switch back on Mains
13. Switch on boiler.

Are we confusing a circulating pump for a shower booster pump perchance? I would think that the pump the OP has would be a dedicated booster and as mentioned above has flow switches which can fail.OP please post up a pic of your pump.The grundfos pump is normally used for circulating your heating water.

WHATS WITH THE BAD MOUTHING OF THE PLUMBER.. he came to fix a tap.. which he fixed.. he had to drain your main tank because the tap which isolates was bust.. not his fault.. yours actually.. when he refills the pump which you already acknowledge was ‘glitchy’ did not work as well as you d have liked.. at this point to be fair to the guy he should have said.. this pumps no good.

what he did like we all do is go the extra mile by working for hours.. your words to try to solve a problem that your responsibility not his he even returnd to have another go after you had ‘a bit of a go’ and all this is his fault..

you have to carry the can for this you did not have the isolater repaired and you did not have the pump properly working all before he arrived to change a tap.

if the job had been described accurately eg replace tap replace iv and replace pump i suspect you d now have hot water at every orifice..

Note the flow booster pump I put link to above can be confused with HW system
pump – but is in fact designed as a HW flow booster – hence in the OP case there
are likely 2 pumps – one for CH/HW tank and one for HW “flow boost” .
The pumps look the same – in the pics above is a CH pump – connected to blue box -diverter valve – which actually switches boiler on/off .

Faulty pump or airlock.
It is negative head, so will be prone to an airlock if anything is drained, or it is run dry.

I’d be looking at where the take off point is for it, and if it is low enough to not run dry.
If it sucks any air in, because the hot water tank cant fill fast enough when you are using water, then you will always have a problem.
Also, some take off points (essex/sussex /Surrey flanges) are prone to admitting air when running, iirc, it is the Sussex flange that is recommended for pumped showers.

Why has a negative head been fitted? Positive head are far more common and more reliable.

WHATS WITH THE BAD MOUTHING OF THE PLUMBER.. he came to fix a tap.. which he fixed.. he had to drain your main tank because the tap which isolates was bust.. not his fault.. yours actually.. when he refills the pump which you already acknowledge was ‘glitchy’ did not work as well as you d have liked.. at this point to be fair to the guy he should have said.. this pumps no good.

what he did like we all do is go the extra mile by working for hours.. your words to try to solve a problem that your responsibility not his he even returnd to have another go after you had ‘a bit of a go’ and all this is his fault..

you have to carry the can for this you did not have the isolater repaired and you did not have the pump properly working all before he arrived to change a tap.

if the job had been described accurately eg replace tap replace iv and replace pump i suspect you d now have hot water at every orifice..

The main reason I’m down on him is the constant lying. I rang him the day after the job was done, over a month ago, he finally came back to look at it today, and in the intervening time I’ve worked from home on four or five different days when he said he was coming but didn’t, and been promised he’d call back around fifteen to twenty times. He may or may not have told me the problem correctly today but the principle reason I’m asking you lot for a second opinion is due to the number of lies from him over the last month.

No pics right now, but it’s a Stuart Turner Monsoon N3.0 bar Single if that enlightens.

Negative head due to shower head higher than cylinder, I think? Was a whole ago…

Thanks people, should have just come on here first with it..

Note the flow booster pump I put link to above can be confused with HW system pump – but is in fact designed as a HW flow booster – hence in the OP case there are likely 2 pumps – one for CH/HW tank and one for HW “flow boost” .
The pumps look the same – in the pics above is a CH pump – connected to blue box -diverter valve – which actually switches boiler on/off .

Aye, that’s it. Two pumps: one like in the piccies above on the heating, no problems there, one on the hot water, totally different, currently not doing owt. Monsoon thingy.

Cheers again y’all

Best get someone to check if there is any pressure in the vessel/if the flowswitch is operating correctly.Very good pumps when looked after.

How much did “john the plumber” charge for changing the tap ?

Most likely to be the flow switch on the pump. Ive had the same with an airlock in the flexible connector between the pump and the house plumbing.

Negative head due to shower head higher than cylinder, I think?

It’s the height of the cold water tank above the shower that’s important as that’s where the pressure comes from.
It does sound like the flow switch in the pump is duff, but then I’m not a plumber.
I’m surprised the whole system had to be drained down – are there not isolating valves just below each of the taps? If not there should be.
If your cold water flow and pressure is OK you could swap the existing HW tank for a pressurised tank – you could then throw away the booster pump and header tank and never have an airlock problem again (plus better HW flow to all your taps and no noise.
Would cost a bit though. I’ve just done this at a house we have (used a booster pump for the shower) and I paid £200 for a used 210L megaflo off eBay and £250 to fit it and a new shower.
I have a booster pump I’m selling.

I have a booster pump I’m selling.

Depending on what is determined when I can get a plumber I trust to have a look, I might be interested in that..

It’s the height of the cold water tank above the shower that’s important as that’s where the pressure comes from.

It isnt, as he has a pump.
With a gravity fed shower, the head height IS improtant to get a good flow, the muppets who did it didnt think about raising the head height, (or couldnt), so suggested a pump.

It isnt, as he has a pump.

It was before he had the pump fitted (he was talking about why the pump was fitted).
Chances are that when the shower was fitted they used one that was for a pressurised system.

OP: I wondering if you can test the pump? If you could remove it (ours was just on push fittings) all you need to do is supply power to it and push some water through – it should switch on.

Actually that’s stupid. Unless I’m missing something, if you turn on a hot tap in the bathroom and water comes out but the pump does not switch on then either the pump is knackered (flow switch of other failure) or it’s not getting power. Surely if you had an air lock you wouldn’t get any water flowing at all?

I am not a plumber but an enthusiastic diyer so take my advice as you see it.

I bet the initial install was done wrong. The pump should have two feeds. One directly from the cold water cylinder in the loft and the other from the top of the tank via a dedicated flange feed.

I tried to bodge my pump in line with the hot and cold feeds to the bathroom taps and it worked sort of but you had to turn a rap on first to clear feed and prime the pump. Same problems as you are experiencing.

Check the feeds to the pump. As soon as I gave the pump a dedicated cold feed with 22mm pipe from the header tank and fitted an s flange in the top of the ch tank feeding the hot supply, all my problems went away.

edlong, how much did the plumber charge you for changing the tap ?

I’m thinking the reason he may have been not to keen to come back was that he ended up spending “hours” trying to fix another plumbers mess (when he came for a simple tap change) and ended up out of pocket (unless he charged full hourly rate for all the extra work ??)

Also you have to realise, you asked him to come and change a tap, a very simple job, yet He ended up spending hours trying to fix something that wasn’t his problem at all.

All that time he was supposed to be somewhere else, and someone else was waiting in for him to arrive and do a job that he missed because he was trying to fix your existing problems.

The pump should have two feeds. One directly from the cold water cylinder in the loft and the other from the top of the tank via a dedicated flange feed.

Why feed cold water from the header tank in the loft? If you do that the tank has to supply the cold feed and the hot feed (via the HW cylinder) and you’d run the risk of running it dry.
If this happened you could suck crap down into the pipework possibly causing a blockage.
I’m also confused as to why a negative head pump has been used if the header tank is indeed in the loft (unless the shower is about 12″ below the tank). It seems if the HW flow without a pump is >1 litre/min then a positive head pump should be used.

I’m not a fan of bad communication from trades, but, reading the OP, my sympathies lie with John the Plumber here.

1. Switch off MAINS
2. Disconnect pump wires (taking a photo of where they go before) – tools needed 1x screwdriver
3. Screw shut both lock valves below and above the existing pump : tool needed 1x adjustable spanner (if they don’t have a handle wheel thing on them)
4. Put old towel on floor beneath the pump
5. Undo the pump connectors (this needs a large spanner, which you might have to buy from Screwfix)
6. Take out old pump, about 80ml of murky water will spill onto towel
7. Put new pump in the space old pump was in. There are two rubber washers, one at each end you need to make sure are in place, these keep the water in.
8. Screw new pump connectors back up (no need to be super tight, the rubber washers create the seal)
9. Double check the new pump is in the right way, new arrow points same way as old arrow
10. Open both lock valves slowly and check for leaks, if it leaks do them back up and tighten up the pump connectors or check that the rubber O ring / washer is in there
11. With Mains still switched off, connect new pump wires back where old pumps wires went.
12. Switch back on Mains
13. Switch on boiler.

you forgot one important point fflaps, to bleed the new pump after fitting. the big silver bleed screw on the front needs undoing a quarter turn until water comes out, pump may not work if its not primed first, also they’re not meant to run dry

Edlong email me. Its in my profile

We had a negative head pump in our last house. After a power cut it often switched back to positive head mode and stopped working as the hot water pressure wasn’t enough to start it up again when a tap was opened. I just had to reset it back to negative head mode and it was fine. Resetting mine (a different pump to yours) involved switching it off and on again within a few seconds.

Second plumber given a raw deal.
Bad installation first time and booster pumps are a problem waiting to happen generally.
He came he did what you wanted and probably didn’t want to come back again as he knows you will only get upset with 2 days solid work and a big bill. It’s not like a car where there is a manual and a diagram of where everything is. Someone could have done anything on the original install which was probably a bodge around of what was already there.

Rip it out and either install a combi or an unvented cylinder but when your quoted £4k for that don’t be suprised.

If your mains water pressure is poor a shower pump or proper booster pump and tank are the only options.

Bad communication is more than likely due to being far too busy and that 90 year olds boiler which has just failed and is a real emergency.

Bad communications also possibly due to spending all day rectifying someone else’s poor quality work, instead of just changing a tap as agreed and going to the next job (as promised to someone else)

You can’t expect him to drop everything spend hours sorting out your unexpected problems, missing appointments with other people no doubt. And then not do the same for other people when it happens.