Watermill Wasp 46 - fails to pump

[suerealisma]

Ok, please come up trumps on this one!

We originally had a mixer shower fitted in our new en-suite, and the "plumber" took the cold supply off the mains(the en suite replaced a kitchenette in a granny flat, hence mains supply). We spent months and money heating our cold water tank in the loft becuase of the pressure through the pipes, not to mention the amount of water that backfilled into the header tank, then overflowed into the garden.

To remedy this I was told a pump would be fitted, the originaly supply pipes to the shower would be capped, and new flexi pipe used, taking the cold supply off the header thank, and the hot off the cylinder. I guess I should have investigated the matter at this point, instead of trusting that the different plumber (who had fitted new rads through the house and seeemed to know what he was doing) did actually know what he was doing

The pump was fitted in the loft, some 12 feet from the header tank, with the cold feed only having a couple of inches drop to the pump, the hot was taken off the outlet at the top of the cylinder, then up to the loft and into the pump. All worked fine for about two months (not sure how when I've read the instruction manual to find the pump should be below the cylinder not in the loft) but now the pump wont come on at all! I've done all the fault finding bits, cleaned filters, checked and changed fuse in plug, but still get nothing. It was most recently coming on, but stopping after about a minute, and now I've found time to try to sort it out, I get absolutely nothing.

I am fast sinking into despair on this one, as the shower has not worked properly now for a year!

HELP.....Sue

 

[hi-spec plumbing heating]

their is no rule that states you can't put a pump in the loft, as long as it is below the cws.
they advice to put near the base of cylinder.
any pump that is above a cylinder requires a anti gravity loop in the hot feed.
you need to check your supply filters to the pump and check your flow switches.

 

[suerealisma]

I've checked the filters, they are clean, how do I check the flow switches?

What does the anti gravity loop look like - bear with me, these things may be logical to a man, but.......................................

 

[hi-spec plumbing heating]

how is the hot feed connected to the cylinder ?
does the pipework have any bleed valves in the loft ?

 

[suerealisma]

hot water is connected from the outlet pipe at the top of the water cylinder, there is a t joint, the supply goes down, elbow joint to right, elbow joint up and into the loft where it connects to the pump through a stop cock to the pump.

I cant see any bleed valves in the system.

 

[hi-spec plumbing heating]

just read the instructions to your shower pump they recomend 2 metres from your cws to the pump.
you don't have 2 metres.

 

[suerealisma]

I agree with that, but why did it work perfectly for a month and only recently stop?

Is the only remedy to resite the pump into the airing cupboard, though God know's where there's hardly room for a mouse! I think that's where the guy was going to put it, but then he decided on the loft because the power supply was easier to access in there!

 

[hi-spec plumbing heating]

when you checked filters was the water getting to the pump ok ?

 

[suerealisma]

Yes, the water was reaching the pump ok, on both feeds.

 

[hi-spec plumbing heating]

the flow switchs are located on the outlets.
if you have a magnet place it in front of the flowswitch and move it slowly up and down the flowswitch to see if that activates the pump.

 

[suerealisma]

I have had a minor success. If I turn the temperature down on the mixer to 25d the pump works, chucking out cold water though at a great force. As I turn it up to 38d the pressure drops and the pump starts straining, and I darent leave it running.

If I turn the stat to 38 before I turn on the shower, it doesnt come on straight away, then starts and stops, but only runs cold (or at least I'm not confident enough to leave it running for ages to see how hot it gets).

It seems that the hot water is not getting to the pump, although there is definitely water there if I turn off the supply to clean the filter, is it just not high enough to get the hot pump to work? The fact that the cold only has a 2 inch drop instead of 2m doesnt seem to be the problem (at least I dont think so).

Is this progress??

 

[hi-spec plumbing heating]

you need to check that you haven't an airlock between pump and mixer.

 

[suerealisma]

Is there an easy way to do that? Do I need to ring my Dad to come to help?

 

[simond]

Your pump is likely to continue to airlock once this is resolved due to the incorrect head of water from the tank. The warranty is invalidated too because the air bubbles are what kill a centrifugal pump in short order.

You almost certainly have an airlock and an old trick is to disconnect the shower hose from the head, place your hand over it and thus backfeed the cold down the hot, pushing out the airlock. You will need to choose a low temp to keep the hot and cold waterways open through the mixer.

This often works ........but this being an internet forum you don't get a warranty.