Auto Filling Bath Project...

["Marcus Warrington" <marcus.warrington@xxxxxxxxxx>]

As part of my ongoing bathroom refit..(can't believe this is taking me
so l=
ong), I've spent the weekend automating the filling of the bath... SWMBO
wa=
sn't initially too pleased about me wasting my time on this
"gimmick" rathe=
r than finishing real jobs like getting the toilet working :-)

=20

The project was made easier by the fact that our "taps" aren't
conventional=
taps but an overflow filler system. The mixer valve (tap) is separate fro=
m the spout itself and so I have  tee'd into the spout supply pipe and
plac=
ed a one way valve beneath it to prevent the water from the new automated
s=
upply from going back to the manual mixer valve . The automated water
suppl=
y is mixed from the hot and cold pipes via a thermostatic mixer valve (off
=
eBay.. =A315) this mixed supply then feeds into an electrically operated
sh=
utoff valve, whose output is connected to the bath supply pipe as
described=
above.=20

=20

The valve is off eBay and is a 22mm automated valve designed to be fitted
i=
n central heating systems, the instructions say it isn't suitable for
mains=
pressure but it seems to work fine for me. The valve itself its sprung loa=
ded so that its default position is closed and the motor then opens the
val=
ve when power is applied. The valve is really quite, in fact as far as I
ca=
n tell its totally silent. There is a slight delay between applying power
a=
nd the valve actually opening, probably about 3 seconds. I would have
prefe=
rred a 24volt model but there didn't seem to be any on eBay at the time so
=
I had to get this 240volt model (=A322).

=20

We have a combi-boiler system and so the flow rate is not high, the bath
ta=
kes about 8-10minutes to fill to a reasonable depth, and I have tested
that=
the overflow rate is higher than the fill rate meaning that even if the sy=
stem malfunctioned and left the bath filling it should never actually
overf=
low the bath itself and flood the bathroom.

=20

At the moment I have the valve operated by an X10 appliance module, that
is=
housed under the bath in a weather proof box. The supply is an RCD spur th=
at I ran from outside the bathroom and is used to power the whirlpool bath
=
motor. The current regulations say the area underneath a bath is deemed
"ou=
t of scope"  as long as you need tools (i.e. screwdriver) to gain
access.

=20

Currently the valve is operated via an RF X10 remote simply turning the
app=
liance module on and off, but hopefully in the next few days I'll find
time=
to program my HomeVision to give me more control. i.e. clicking a button o=
n the remote (or using the touch screen in the dining room) will send an
X1=
0 message that will tell HV to start filling the bath for 8minutes and
then=
switch off. Also by clicking another button the night, HV will  know  that=
I want a bath in the morning and so start running a bath the following mor=
ning so that its ready for when the alarm goes off.

=20

X10 seems pretty reliable in our house, but I'd prefer to have something
ha=
rdwired just in case.. don't fancy a phantom X10 signal filling bath all
da=
y..

I have a Dual Pole relay board that I got from eBay that I hope to use..
on=
ly thing is that this has both connections for the 240volt stuff and then
a=
lso for 12volt stuff to to trigger the relay. I'm slightly nervous about
ho=
using both 240volt stuff/wires in the same housing as a lowvoltage feed
(i.=
e. cat5e wire ran back to Homevision). Anyone have a suggestion about the
s=
afest way of doing this... my guess would be either some form of opto
isola=
tion or a magnetic reed switch inside the enclosure, and the trigger
mechan=
ism (opto or magnetic) housed outside the enclose

=20

The big stumbling block at the moment is trying to automate the popup
waste=
... currently we have to remember to make sure the plug is "in"
after empty=
ing the bath, otherwise the next autofill just goes down the drain rather
t=
han filling the bath.

=20

The plug is operated via a cable that runs from the overflow (twisting
left=
or right opens or closes the waste)  to the popup waste. I'm thinking that=
I may be able to cut back the sleeving of this cable and solder on a secon=
d cable that could then be driven via a suitable stepper motor... another
t=
hought was that maybe some form of magnetic coil could be wrapped around
th=
e existing cable sleeve and used to push/pull the internal cable to
activat=
e the plug.. ?

=20

Marcus=20



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