I am planning to fit a timed extractor fan into the bathroom. Ideally,
it should only come on when the power shower is used. I have a Wickes
Twin Impeller Shower Pump (product code 410042), and was hoping to
wire the fan into the control board of the pump.

I was expecting to find a place on the circuit board which only
becomes live once the pump is activated, but after some probing around
with a multimeter, it seems that every potential place is already live
all the time. Does anyone understand how this circuit board works, or
perhaps have a schematic for it?

Clive Backham wrote:
I am planning to fit a timed extractor fan into the bathroom. Ideally,
it should only come on when the power shower is used. I have a Wickes
Twin Impeller Shower Pump (product code 410042), and was hoping to
wire the fan into the control board of the pump.

I was expecting to find a place on the circuit board which only
becomes live once the pump is activated, but after some probing around
with a multimeter, it seems that every potential place is already live
all the time. Does anyone understand how this circuit board works, or
perhaps have a schematic for it?

Why not just control the fan from a humidistat?

http://www.tlc-direct.co.uk/Products/BGREMHM.html

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 2 Sep, 19:54, John Rumm wrote:
Why not just control the fan from a humidistat?

http://www.tlc-direct.co.uk/Products/BGREMHM.html

Interesting option which I hadn't considered. Thanks for pointing it
out. (But I'd still be interested if anyone can shed some light on the
shower pump circuitry).

Clive Backham wrote:

I was expecting to find a place on the circuit board which only
becomes live once the pump is activated, but after some probing around
with a multimeter, it seems that every potential place is already live
all the time. Does anyone understand how this circuit board works, or
perhaps have a schematic for it?

Surely the supply to the pump is only live when the pump is running -
can't you just connect there?

Ben.

"Clive Backham" wrote in message
ups.com...
I am planning to fit a timed extractor fan into the bathroom. Ideally,
it should only come on when the power shower is used. I have a Wickes
Twin Impeller Shower Pump (product code 410042), and was hoping to
wire the fan into the control board of the pump.

I was expecting to find a place on the circuit board which only
becomes live once the pump is activated, but after some probing around
with a multimeter, it seems that every potential place is already live
all the time. Does anyone understand how this circuit board works, or
perhaps have a schematic for it?

Fit a shower light/extractor fan over the shower with a fan override.
Available from B&Q, Wickes etc. When you have a shower the light is on. Can
be operated via pull chord or on the main bathroom light switch.

Clive Backham wrote:
On 2 Sep, 19:54, John Rumm wrote:
Why not just control the fan from a humidistat?

http://www.tlc-direct.co.uk/Products/BGREMHM.html

Interesting option which I hadn't considered. Thanks for pointing it
out. (But I'd still be interested if anyone can shed some light on the
shower pump circuitry).

Install a flow switch in the water pipe from the pump then. Use it with
a fan designed to be controlled via a light switch that has an overrun
timer. Better still "wire or" it with the humidistat. So the pump
turning on starts the fan, the humidistat keeps it going long enough
after to dry the room.

I did a ducted fan combined with a shower light, that worked on a remote
humidistat. Worked nicely. Gave you a light over the shower, steam
extraction from the source, low noise, and automated operation that
controlled the humidity.

http://www.tlc-direct.co.uk/Products/BGSLC.html


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Ben Willcox wrote:
Clive Backham wrote:

I was expecting to find a place on the circuit board which only
becomes live once the pump is activated, but after some probing around
with a multimeter, it seems that every potential place is already live
all the time. Does anyone understand how this circuit board works, or
perhaps have a schematic for it?

Surely the supply to the pump is only live when the pump is running -
can't you just connect there?

The supply to these pumps is usually permanent, operation being
controlled from an internal flow switch.

Personally I would steer away from doing anything that required internal
tinkering with the pump, since you will potentially have problems should
you ever have to replace it later; especially if with a different model
or version.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article . com,
Clive Backham wrote:
I am planning to fit a timed extractor fan into the bathroom. Ideally,
it should only come on when the power shower is used. I have a Wickes
Twin Impeller Shower Pump (product code 410042), and was hoping to
wire the fan into the control board of the pump.

I was expecting to find a place on the circuit board which only
becomes live once the pump is activated, but after some probing around
with a multimeter, it seems that every potential place is already live
all the time. Does anyone understand how this circuit board works, or
perhaps have a schematic for it?

You'd need to find the output side of the flow switch. However, tampering
with this wiring would rightfully void the warranty - the switch might
well not have any spare capacity for extra load. Also if I really wanted
to do this and wasn't concerned about the warrenty I'd use a relay or even
a second flow sensor.

--
*When it rains, why don't sheep shrink? *

Dave Plowman London SW
To e-mail, change noise into sound.

Thanks to everyone for their suggestions. I'll have a rethink about
how to go about this.

"Clive Backham" wrote in message
ups.com...
I am planning to fit a timed extractor fan into the bathroom. Ideally,
it should only come on when the power shower is used. I have a Wickes
Twin Impeller Shower Pump (product code 410042), and was hoping to
wire the fan into the control board of the pump.

I was expecting to find a place on the circuit board which only
becomes live once the pump is activated, but after some probing around
with a multimeter, it seems that every potential place is already live
all the time. Does anyone understand how this circuit board works, or
perhaps have a schematic for it?

If you really want this idea fit a flow switch in the hot water supply to
the shower. About £25 from Farnell.