Udon Thani Thailand Forum - Udon Thani, Thailand

Hi all,

After your thoughts on if my water pump is operating correctly.

When taking a shower the pressure 'pulses' every few seconds. I.e the pressure drops slightly then returns to normal.

It's not a significant pressure drop so doesn't cause any problems but is noticeable.

Is this normal? The water pump is one of the inverter types.

Thanks.

Depends on the pump - can be perfectly normal, particularly if it's a small pressure tank.

Sounds similar to a problem we were having with one of our pumps. On the top of one of them we bought there was a small dome, the builder took this off and under it was a small screw on what looked very similar to points on an old fashioned car, he turned the screw 1/4 to a 1/2 turn at a time and it sped the pumping action a little bit more each time until it stopped pulsing, could be the same issue you're having. By the by, I'm pretty sure the area he was poking around in was live so be careful.

Try turning the pump off & the inlet valve.
Then drain the pump by the plastic plug at the bottom of the pump.
You should also take off the plastic plug on the top of the pump to allow it drain properly.
This allows air into the tank & gives you a cushion of air in the tank.
There is an air charging system on the pump to do this automatically but sometimes after running for long periods it needs a little help.
If you still have the manual on the pump it will show the plugs & air charging system

vincemunday wrote:Sounds similar to a problem we were having with one of our pumps. On the top of one of them we bought there was a small dome, the builder took this off and under it was a small screw on what looked very similar to points on an old fashioned car, he turned the screw 1/4 to a 1/2 turn at a time and it sped the pumping action a little bit more each time until it stopped pulsing, could be the same issue you're having. By the by, I'm pretty sure the area he was poking around in was live so be careful.

Sound like he was adjusting the pressure switch.
You should not do this unless it is really a last resort.
By adjusting it you can change the differential pressure the pump cuts in & out & make things worse.

I agree, never touch the pressure switch.

Our Hitachi pump has been pulsating for the last four months, the local well mech out here had a look and said it was a small rubber seal inside the impeller, more than likely due to the high salt content in the water here, quite a simple repair just haven't got around to it yet, it only doe's it on low pressure flow so I now turn the basin tap on a little when I shower and it stops, as the pump is about ten years old I don't know whether I will bother repairing it or just get a new pump although my pump in Aus is about twenty five years old and never missed a beat.

Thanks for the advice guys.

I have the Hitachi inverter pump, I think 250 watt.
If you have the same or similar brand inverter then under the cowling you will see a electronic control unit. Maybe a digital display? This unit will allow switching between hi or lo pressure operation. If you use 1 or 2 outlets at the same time then the lo setting is fine. If you have your household outlets elevated as in upstairs then the hi position can be used. Washing machines can affect a faulty unit. The electronic control panel can also be a diagnostic type tool for problems.
Perhaps as an experiment switch it to hi if it is now on lo.
All pumps should have a pressure switch already mentioned by others, but an inverter pump has a pressure sensor not a switch which electronically tells the electric DC motor to speed up or slow down according to pressure needs.
If the pressure is surging as you advised then it may be the sensor that is playing up. Just a thought. A reputable pump shop in town should be able to advise.
An inverter should not surge.
Good luck

based on that said, then if one is in the shower, and then I missus in the kitchen uses that sink tap, does the pump automatically speed up to compensate, and slow again when she turns off the tap..

maaka wrote:based on that said, then if one is in the shower, and then I missus in the kitchen uses that sink tap, does the pump automatically speed up to compensate, and slow again when she turns off the tap..

Correct maaka

Its a subtle change, it is all automatic with inverter types, same with AC units, there is no stop start action just a SEAMLESS operation, there's that word again.

A constant pressure pump will turn on and off when the outlets are turned on and stay at the set pressure on the pressure switch.

Can I suggest that you shower together to save soap and any pressure problems and maybe you can then watch her wash up at the sink. Win Win again.

maaka wrote:based on that said, then if one is in the shower, and then I missus in the kitchen uses that sink tap, does the pump automatically speed up to compensate, and slow again when she turns off the tap..

With my pump at the moment yes, if the water flow rate is strong it's ok and dosen't pulse, now that it's warmer I don't have to run the basin I can just crank the shower up, being a softie I like hot water through the winter months, if the shower is running strong to stop the pulse the water is cool...

Geez Barney, been with the trouble and strife for 14 years, don't want to spoil her now...

I can only sapeek on my pump , it's a deepwell pump "34mtrs plus" it pulsates from time to time this tells me it needs draining as not enough air inside ,once drained all is well ,

I took a recommendation off of here to go to Udon Hardware to buy water pumps. Steve, the American Thai who owns it is an absolute gem, he gave us so much information and we got the Hitachi pumps at a very reasonable price. The shop is based on the Phosri Road about 200m on the left after the the fountain roundabout heading towards UD town, I highly recommend these people and I will use them again. it might be worth visiting him, he's very knowledgeable about pumps.

Thanks. Too much rain today to be messing about in the garden with the water pump. Will wait until the sun resumes and get the cover off and have a look.

Its a Hitatchi Invertor pump we have got.

Thanks

deankham wrote:Thanks. Too much rain today to be messing about in the garden with the water pump. Will wait until the sun resumes and get the cover off and have a look.

Its a Hitatchi Invertor pump we have got.

Thanks

How about faucets? Same problem? If not, take shower part off and check, if pulsing. If pulsing, problem with water coming from pump to shower, because other faucets work fine.

If not pulsing, clean you shower from dirt. I had same problem with my toilet and cleaning intake filter helped. Shower also has a small filter. Of course holes could be blocked and make water pressure high and switch off the pump.

That problems comes after few years use and is caused by all dirt in water. It is much cheaper to change/clean shower than a pump.

Ps. I had same pulsing problem with one faucet just after house was built. Cleaning a filter inside helped.

Easy fix, take the main cover off, locate the pressure switch, small cylindrical with another cover, remove cover and you will see a screw with + and _ either side turn screw until it stops coming on and off. always have to do after fitting new pressure switch, every 2 or 3 years.

pal52 wrote:

vincemunday wrote:Sounds similar to a problem we were having with one of our pumps. On the top of one of them we bought there was a small dome, the builder took this off and under it was a small screw on what looked very similar to points on an old fashioned car, he turned the screw 1/4 to a 1/2 turn at a time and it sped the pumping action a little bit more each time until it stopped pulsing, could be the same issue you're having. By the by, I'm pretty sure the area he was poking around in was live so be careful.

Sound like he was adjusting the pressure switch.
You should not do this unless it is really a last resort.
By adjusting it you can change the differential pressure the pump cuts in & out & make things worse.

I suggested this at the beginning of the thread, apparently it's not the way to do it, it's worked fine on mine for a couple of years but it's probably better to take advice from a pro.

Why not? do it all the time

i have been adjusting these pressure switch of the thai type pump for 15 years now without any problems , if your pump starts switching on and off all the time when you open you will need to adjust , mostly you increase the pressure a little
by turning down (clockwise) the small middle screw of the pressure switch, open a faucet on low water pressure , this is when the pump start mostly do idiot and adjust until the pump keeps running smoothly , and look she also stops after you close the water ...most problems come because of the small electric water heaters with the low flow of the small piping inside , anyway i do not use these pumps anymore (except on the well)due to too many problems , pressure switch (400 baht), condenser (450)and water tank(3.000 , 500 small ones)even stainless too quickly rusted , use now grundfos mq45 pump (2) without any problems , more expensive (12.500 baht) but a lot better ...as info ....

Thanks for the advice. As soon as the sun returns I'll put on my PPE and venture out into the garden with tool kit in hand.