We have a Mitsubishi water pump that we only need to use when the town water is either very low pressure, or like this morning non-existent. I turned on the tap that activates the pump, but nothing happened. I remember the last time we used it, it took some time before it switched on, but today it hasn't happened. I checked the two reservoirs at the top of the tank and both are filled with water, so I don't know what other checks I can do before I have to call in the "professionals".

I managed to get it working, but I'm not sure how. I decided to take a couple of buckets of water from the underground tank that the pump siphons from, in the process I may have moved the float for the ballcock a tad, and that seemed to activate the pump. So maybe the water level is too high in the tank, don't really know.

Is the pump to pump water into the tank or out?  Anyway, if you push down on the float and the pump starts then turns off when you let go (assuming full tank) then your pump is either for putting water into the tank or shouldn't be triggered by the float.

 

4 minutes ago, bankruatsteve said:

Is the pump to pump water into the tank or out?  Anyway, if you push down on the float and the pump starts then turns off when you let go (assuming full tank) then your pump is either for putting water into the tank or shouldn't be triggered by the float.

 

The pump is to take water from the tank, the tank is a reserve supply that I only use when the town water is off.

Then is should not be triggered by the float, if it is.  Otherwise, perhaps it froze up from inactivity and happen to unstuck itself when you were bumping around.  

Our Mitsubishi water pump 280ex acted in much the same way as you describe, when switch on it worked sometimes and sometimes not, l hit it with the Irish screwdriver a few times and it worked but eventual a Thai guy knew what it was, the part he replaced was on top, a kind of electrical switch which looked a bit like points to me from a car distributor.

Can't remember how much but not expensive otherwise l would remember. 

43 minutes ago, Kwasaki said:

Our Mitsubishi water pump 280ex acted in much the same way as you describe, when switch on it worked sometimes and sometimes not, l hit it with the Irish screwdriver a few times and it worked but eventual a Thai guy knew what it was, the part he replaced was on top, a kind of electrical switch which looked a bit like points to me from a car distributor.

Can't remember how much but not expensive otherwise l would remember. 

I know the part you are talking about, I think I need an expert to have a look at it.

22 minutes ago, giddyup said:

I know the part you are talking about, I think I need an expert to have a look at it.

 

That would be the pressure switch and is prime suspect for being the cause.

 

Next time it fails to start give the switch a gently thump with a rubber mallet (ok, piece of wood). If it starts you could try spraying some WD40 in the switch (power off) but they're not expensive to replace anyway.

4 hours ago, Crossy said:

 

That would be the pressure switch and is prime suspect for being the cause.

 

Next time it fails to start give the switch a gently thump with a rubber mallet (ok, piece of wood). If it starts you could try spraying some WD40 in the switch (power off) but they're not expensive to replace anyway.

Thanks, it sounds like the pressure switch may be the culprit.