Shower Pump - Air Lock?

Our shower pump has just died, and we've bought an exact replacement (a NewTeam varispeed 50). When the old one died, water would simply flow through it and out of the shower, albeit not at much pressure.

We fitted the new one yesterday. Although 3 out of 4 pipes in/out of the pump had valves in the pipes, the fourth (cold water feed in) didn't, so we drained the water tank in the attic before opening up the pipes, and swapping over the pump.

When we came to use it today, the pump switched on for a few seconds, then shut down, with no water coming through at all. The pipes were boiling hot, and it seems that the cold water feed isn't getting through. Although we ran water through the pump before switching it back on, as in the installation instructions, we didn't realise that the shower temp had to be on full-cold, so there seemed to be water coming through fine (the hot tank was empty so I presumed the water from that was the cold feed...)

Now, however, even with the pump switched off at the mains, no cold water comes through at all. We've tried taking the shower head off and turning the cold on, but nothing comes out, even after a few minutes.

I presume there must be an air lock somewhere - does that sound likely? If so, how do we get it out? Do we need to drain the water tank and refill it again?

Any ideas would be appreciated.

I'm confused by your post.

You say that you didn't realise that the shower setting should have been full-on cold, which implies that it wasn't, but you say that there was no hot water coming through, which implies that the water must have been from the cold supply, but you believe that the cold is air-locked?

I suggest that you put a bung in the cold water outlet from the cistern, then disconnect the cold inlet to the pump and put a valve on it. Then you have full control and can unbung the cistern.

You can then leave the cold inlet disconnected and open the valve to run cold water into a bucket or bowl. If no water comes out then you have a blockage, which could be air but might not be. If you believe it to be air in the pipe then you could connect up a hose pipe to backfill it, or use a wet-vac, or suck very hard

What I meant was that the temperature dial wasn't all the way to the cold, but not that far off. The water coming out felt cool, so I thought that was OK. I then realised that the hot water supply was also coning out cool, 'cos the tank was empty. In our relief to have a powered shower after 2 weeks I didn't think through the implications of telling between hot and cold

I'll send hubby up to look in the water tank and see if he can see where the shower pump feed is coming from, and whether it can be blocked. Otherwise we'll have to call in someone who knows what they're doing... (Having said that, the "pros" who built our house left a leak in the airing cupboard which manifested itself through the hallway light fitting , not to mention initially plumbing up the entire cold water feed to the pump (the loos didn't half fill quickly though!). Good old housebuilders!)

Right, off to the attic...

WestEndGirl said:

I then realised that the hot water supply was also coning out cool, 'cos the tank was empty.

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This is the bit I still don't get - how could hot water be coming out if the tank was empty?

WestEndGirl said:

Right, off to the attic...

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Are you both off up there then?

Sucking out from an Essex flange perhaps

lolapm

Softus - we'd refilled the cold water tank, after draining it to fit the pump. The hot water tank was empty/cold.

And there was me thinking there was straightforward answer to my query - yes, no cold water flow though shower pump, sounds like there's an air lock/blockage whatever.

That's why I posted here - it seemed like a helpful forum. My mistake.

WestEndGirl said:

Softus - we'd refilled the cold water tank, after draining it to fit the pump. The hot water tank was empty/cold.

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If you refilled the cistern, then the DHW cylinder would also be full, unless you'd isolated it with some valve that you didn't mention. Being full of cold water is not the same thing as being empty of hot water, not by a long chalk.

WestEndGirl said:

And there was me thinking there was straightforward answer to my query - yes, no cold water flow though shower pump, sounds like there's an air lock/blockage whatever.

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There is a straightforward answer, it's just that we haven't got there yet. Do you not have the slightest sympathy with the difficult position of trying to diagnose a problem using only my keyboard for input and yours for output?

WestEndGirl said:

That's why I posted here - it seemed like a helpful forum. My mistake.

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Whoa there lady - there's no call for that kind of comment. Starting to get arsey would be a great way for you to attract a somewhat defensive and decidedly unhelpful response, which is exactly what you haven't had so far.

Softus - sorry I wasn't getting at you - it was this response I didn't appreciate...

doitall said:

Sucking out from an Essex flange perhaps

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I appreciate your attempts to help me and my confused keyboard inputs. My father-in-law's coming over tomorrow to lend my husband some moral support on his journey into the attic (how hard can it be...) so hopefully once he's checked the water tank for a blockage and we've checked the pipes into the pump for air locks, it should be nearer being sorted.
Thanks again.

OK - wires crossed. Offence neither taken nor meant.

Good luck - and please let me/us know the outcome so that others can benefit from the experience.

All sorted now - we shut off the hot water feed from the shower pump, leaving only the cold water feed out, which was blocked. Turned the pump up to full pressure, and out came some green gunk, followed by water - yeay! No need to drain the tank this time, so better for the water bill, not so good for the garden!
Thanks for your help.

Unless the green gunk was limescale, which is unlikely, I would be concerned, because it's either corroded copper or bacterial growth.

I would gently suggest that you look in the cistern in the loft and check the water condition, and check that the cistern is fully lagged.