I am visiting my Thai in-laws in Sukhumvit 85, and they have a very noisy water pump which cycles on and off about once a second whenever a tap is opened.  My in-laws have no clue about anything mechanical, and have no contact with any plumber that can do anything more than change a washer.  
 

Coming as I do from UK, I have no experience of this kind of pump, so can anyone recommend a competent repairman near Soi 85 please who would come to investigate, repair, and repace (if nessary) with reasonable call-out charge?

11 minutes ago, abenn said:

I am visiting my Thai in-laws in Sukhumvit 85, and they have a very noisy water pump which cycles on and off about once a second whenever a tap is opened.  My in-laws have no clue about anything mechanical, and have no contact with any plumber that can do anything more than change a washer.  
 

Coming as I do from UK, I have no experience of this kind of pump, so can anyone recommend a competent repairman near Soi 85 please who would come to investigate, repair, and repace (if nessary) with reasonable call-out charge?

Normally shops that sell pumps/tanks will have contacts they can recommend.  But it may be operating properly if an on demand type without a pressure tank.  Had to remove window in our home due to a neighbors (and they actually tried to reduce noise at one point with an enclosure).  We use Grundfos like below for that reason.  But if you take model type information to shop they should be able to advise if normally a noisemaker or not.

Thanks lopburi3.  I should have said it's a Hitachi 250 watt device with a pressure tank, so it should be cycling on/off much less frequently than it is.  Once a second with only one kitchen sink tap running is definitely not right, and it's the on/off which is the nuisance rather than the actual motor noise, though that's a bit louder than I remember from my last visit this time last year.

 

The complaining neighbour is another sister-in-law, and she's just as mechanically ignorant as our house!

Likely no air in the tank in that case and maybe just empty and fill again will correct.  But could also be tank itself if a hole or bladder failure.  Any water pump worker should be able to fix or you can try the empty and refill first.

Ok, the tank was drained and refilled the other day, so bladder failure sounds possible.  Given the age (believed to be about 7 years), I'm sorely tempted to just go to HomePro and get a replacement.