Please see below. Also, search for Pigletjohn's opinion.
This was written on another website, if you still want one after reading this, go ahead. :LOL:
Sell the house, failing that give it away, if that doesn't work pay
someone to take it or burn it down.
To give you a clue - these ghastly instruments of the Devil are
French. Add the French and lavatorial engineering - now see why I
say get out while you can. Moreover this particular Frenchman was a
lunatic with strong Anglophobic tendancies and a bad case of
coprophilia.
I am quite sure the designer was also an ex-submariner Frenchman who
missed the strangled screams of seamen who had got the valve sequence
wrong in the submarines toilet and just been rinsed down with a few
gallons of seawater (and the recently donated contents of the bowl).
They break down at the slightest opportunity. The only thing you can
actually guarantee about them is that they will break down - very
frequently.
Basically the only way of maintaining the slightest semblance of
serviceability is to impose on pain of repair the same rules as for a
small yachts sea toilet - if it hasn't passed through you it doesn't
go in the bowl.
They have an interesting design. The motor has poor starting torque
and the macerator lots of tiny teeth. Ergo anything that has strands
in it catches on the teeth and stops the motor from starting. Things
with strands include anything with cotton wool (including cotton wool
buds) and anything with cloth. Females in particular must not be
allowed anywhere near these devices. If you were unfortunate enough
to have the added misery of a sink (oh dear - you were) then add
hair, strands from wooly pullovers and almost anything else thats at
all fibrous.
When they break (which they will - that's an absolute certainty)
their endearing characteristic is that you are left with a bowl full
of whatever which you have to empty back the way it came and more
importantly many feet of 40mm pipe still full of minced whatever.
When you disconnect the pipe I'll give you one guess where its going
to go. Repairing or unblocking them is the most thoroughly revolting
job.
Now to get to specifics - the pulsing is a fault in either
installation or the pressure switch. Does it pulse with just the
cold water tap running from the sink? The way they work is a low
pressure trip switch switches on the motor when the small holding
tank is full. This tank remains partially full all the time. If its
pulsing either the switch has too low a hysterisis or water isn't
getting into it fast enough. The motor should remain on for a few
seconds after everything has emptied so that pulsing you are seeing
shouldn't be happening.
As the failure rate of these diabolical things is worse than that of
a F104 Starfighter I'd suggest you get the installer back (preferably
to remove it forever). If it was installed by yourself then self
flaggelation with a few lengths of barbed wire and a call to the
Saniflo people might be in order.
Also, my system is a Sanitop with the outflow from a washbasin going
into the top of the unit. I find that running the tap for a few seconds
activates the Saniflow. Is there any way of adjusting the sensitivity of
it so that it will only run when a reasonable amount of water has gone
into the unit.
No, but if its oversensitive this might be related to the pulsing you
are seeing.
I dont see why the washbasin water cant just bypass the
cutter/pump internally.
Because these horrors are designed to be installed pumping upwards -
the raving idiot who designed them thought it would be pretty neat to
have something you could stick in a downstairs cloakroom and run the
pipe upwards to join the soil stack in the bathroom. If that's how
your installation goes cut out the selling the house bit - just burn
it now. When it fails there is 10ft of pressurised whatsit just
waiting for that final turn on the drainpipe.
The other reason the sink must go through the pump is that the outlet
of the thing is at some pressure. Connect the sink a bit downstream
and every time you pull the chain the contents of the loo make a
pretty little fountain out of the sink plughole (I've seen one
plumbed like that - the owner kept a sandbag in the sink on top of
the plug).
Some models have an interesting feature - on the top is a reset
switch, under the top cover is a screwdriver slot on the top of the
motor drive shaft to allow you to clear the (frequent) blockages.
However to get the top cover open to get at the drive shaft to free
it - you've guessed - you have to disconnect the drain pipe.
How they can be called Saniflow when they are anything but sanitary
(as you will soon find out) and rarely flow is beyond me.
As I said - sell the house.