Power Shower Wiring

[Andy625]

I live in a house that was built in 1999. It had a Power Shower (pumped water from the tanks - not electric shower) fitted from new. We've had a couple of shower units where the motor in the shower has become either jammed or partially jammed, resulting in lots of noise and a little smoke on one occasion. Although the house has MCB's and an 30ma RCD (which the iron trips out regularly), whenever the shower's played up though, nothing trips. I assume as nothing is leaking to earth, and the extra current flowing is less than the 6A required to trip out the breaker.

The shower is powered from a spur off the upstairs lighting ring which has a 6A MCB in the fusebox. it has a two-pole pull switch just near the cubicle, but I cannot see any independent fuse. No-on'e ever touched the wiring in the house since it was built - we're the only owners. Does this sound like its wired correctly?

As the showers seem to fail on a regular bass, I'm thinking of putting in a fused spur with maybe a 3A fuse, so that the fuse will blow before anything starts getting hot. Does this sound like the thing to do?

 

[Octopus]

Isn't there a fuse spur before the shower unit. if there isn't, it would be a very good idea to fit one. Whether a 3A cartridge fuse will blow before a 6A mcb is another question!

 

[Andy625]

There isn't unless it's buried in the loft. Seems like the mcb will let the thing go up in flames before it trips out, so got to be better than that!

 

[ifindoubtdont]

You say this jamming has happened a couple of times on different shower units, I think I would be looking to find out what is causing the pump to jam. Take a trip into the loft and see if your header tank is open topped, if so any old crud could have got in and this may be what is jamming your pump.

 

[Andy625]

It's normally the motor that jams as the shower is a cheap unit and over time the moisture in the cubicle causes the motor from to corrode and distort. I've never tried a different make til now as it would've involved changing the plumbing - something I'm not too hot on.

 

[jaypp]

You say this jamming has happened a couple of times on different shower units, I think I would be looking to find out what is causing the pump to jam. Take a trip into the loft and see if your header tank is open topped, if so any old crud could have got in and this may be what is jamming your pump.

also they should have their own cold feed from tank and hot feed as close to being first draw off from cylinder. if not, water is limited and could cause pump to fail prematurely.

 

[Andy625]

Ok checked the header tank, and that's got a cover on it. Shower has a cold feed straight out of the roof and a hot fed from the top of the hot tank directly behind the wall where the cubicle is. I'm pretty sure the plumbing is ok. The showers have all been Showerforce/New Team until now. We've just switched to a Triton. The New Years all had the motors at the bottom of the housing so that any condensation or drips would go over them and get them rusting away nicely. The frames then seem to distort enough that the plastic cooling vanes rub on the motor frame, get hot and smell or jam the motor. We had one spring into life even though it was turned off at the unit, and just sat there buzzing, sparking Nd smoking, until we pulled the isolator cord. SURELY that should have tripped something??

 

[jaypp]

you'd like to think so, but i'm guessing lighting circuits not on rcd. might be wise to get it checked.
never had problem with new team except rotary lever breaking. triton, if the unit gets wet, will run even when start/stop button is in 'off' position. perhaps someone on here is local to you and may have come across this before.
sorry can't help further. oh, does the unit/cover sit 'true'? and fused isolator, as murdoch said above, good practice

 

[Andy625]

Going back to the old Showerforce showers, for information here are a few pictures of the Showerforce shower that failed in 2008. We've got through 2 more since then! I took these about 2 days after it was last used. Note all the condensation inside the housing, and the position of the motor directly underneath the water valve. When I fitted the one after this I sealed all the screw holes where it screws to the wall, but it made no difference.

 

[Andy625]

Isn't there a fuse spur before the shower unit. if there isn't, it would be a very good idea to fit one. Whether a 3A cartridge fuse will blow before a 6A mcb is another question!

It turns out that the circuit that supplies the shower (upstairs lighting) is not RCD protected, so would it be acceptable to fit a fused spur with a separate RCD at ceiling level in the bathroom next to the pull cord for the shower?

 

[Andy625]

Can anyone advise? Seems logical to me - its not like you're ever going to need to touch it unless there's s problem.

 

[telectrix]

fit a RCD FCU. just fit outside xones ( >0.6m from shower enclosure. )

 

[Andy625]

Thanks, that sounds good although typically the existing pull switch is about 500mm from the cubicle. I guess we'll have to leave a bit of a gap. I checked in the loft earlier, and there's definitely not fused spurs up there. When they built the place, the builders just wired to the shower switch as if it was another a ceiling rose.

 

[ifindoubtdont]

Andy, looking at those pictures you have a serious infestation of water. It might now be a case of arming your self with plenty of tubes of sealant and plug every hole you see.

 

[Andy625]

Andy, looking at those pictures you have a serious infestation of water. It might now be a case of arming your self with plenty of tubes of sealant and plug every hole you see.

Yes I was horrified to see all that in there. The next one I fitted I did seal absolutely everything - and it made no difference at all. I think that type of shower just leaks over time and wrecks itself. This is why I'm changing to a Triton. The New one has the motor at the top of the enclosure so that if any water does see our, it won't go over the motor.

The main problem I have at the moment is where to put the RCD spur. I've just been told by an electrician that I can't put it in the bathroom, even outside the zones, and it has to go in a separate room.