Water Pump Switching..

[LivinLOS]

OK I have just moved into a new rental house.. The place is split into 3 levels on a hillside and has a couple of large water tanks to ensure solid supply.

The problem I have is the builder is the usual comedy of errors that happens when a Thai contractor attempt to develop above thier skills, theres light switching systems that should be dual point (both ends of stairs control the light) where one end totally over rides the other, a lack of plug points, the worlds ugliest / cheapest trip switches prominently displayed in visible places.. Its been finished nicely and its a lovely big spread but high end villa it isnt by normal standards !!

Now when they built this they didnt put a header tank in the roof for the cold water supply, there is a tank in the roof for the hot water that supplies the top level baths and the lower level is cold only (will put a electric heater under kitchen sink).. The house cold system is pressurized by a pump thats down in the pool pump room, thats below the lowest of 3 levels so means the pump has to push water up 4 levels !!

The farang owner fitted a (very expensive so he tells me) monster pump down there to provide adequate pump power / pressure and once the pump is working there is no real problem. The problem I have is the pump seems set up to trigger based on system pressure as it sits 4 stories below the highest tap when you turn on a tap on the top floors it takes a good while (30 seconds or more) to detect that the pressure is a dribble before it senses flow (via dropped pressure) and starts pumping. Then all is well except if your showering and adjust the flow down it thinks its job is done and cuts the pump.. Not so good while in the shower, sudden scalding water !!

Is there any way to adjust the sensitivity ??

Can a flow sensor be installed instead of measuring pressure so deep under the rest of the system ??

Can the system be pressurized more so the pump is more likely to push harder and hence know faster when low flow cold is used ?? Once 'on' the pump pushes water very solidly even right up on the top.

Fitting a new header tank up top wont be easy.. sealed roofspace, unknown roof strength, tapping the system, routing filler tube to the top etc etc etc..

Currently deep into moving sat dish instals, multi zone TV distribution, new plasmas around, projection theater install, whole house audio, networking installs, etc.. Would rather not have to replumb the house too !!!

[Crossy]

'Most' pressure operated pumps are adjustable in some way or other.

Of course, some pumps are easier to adjust than others (luck will dictate you have on of the 'others' group), I suggest your first foray should be into the pump room and get the make and model off the pump

EDIT since the cold flow is OK once it gets started you're probably going to be able to up the stop pressure a bit

[LivinLOS]

Go down into the pump room ?? are you mad !!!

I am far better in a pointing and paying capacity

Hang on.. I'll get a torch !!

[Crossy]

I reckon LivinLOS has been eaten by the beasties that inhabit his pump house

Seriously, what about installing a small auxilliary pump at the top level to provide more constant flow to the showers and even out the hysteresis of the big beast in the basement. Comments anyone??