Low water pressure - how and who to fix?

[flipper2222222]

hi list, 

at a 2 level property in Bang Khen the water pressure upstairs and downstairs is very poor, there is small pump (possibly too low a capacity), some sort of water reservoir and plumbing pipes.  My wife says other units in the block don't have this problem (not verified).

 

I have attached some pics.

 

Does anyone know what the problem might be and or suggest a reputable company to quote and fix?

 

thanks in advance 

[Crossy]

Does the pump run when you open a tap?

 

[flipper2222222]

yes it runs but the water flow is much less than desired. 

 

I am comparing the water pressure to my place in Australia which would be 5 X stronger.

 

A shower is possible, but not particularly enjoyable.  Am I asking too much from the water system in Bangkok??

[Crossy]

Check the crunchy rocks mesh filters in your water heater and taps.

 

Pump is pretty small but look for blockages first.

[Here2008]

3 minutes ago, flipper2222222 said:

Am I asking too much from the water system in Bangkok

 

Probably -- If you are expecting a high pressure domestic water supply you will be disappointed. You should compare the water pressure in your accommodation with that which one or more of your neighbours have.  If there is a significant difference your system is in need of trouble-shooting. 

[shady86]

Did you open up your taps and fittings to clear out small stones which might slow down water flow?

[chickenslegs]

2 hours ago, flipper2222222 said:

Am I asking too much from the water system in Bangkok??

You have a self-contained system. So the only thing that the Bangkok water system does is fill your tank. Water pressure and water flow into your house is all dependent on your pump, valves and pipes. That pump size seems OK for a 2-storey house (31 litres/minute at the higher point), but it may not be working at full efficiency.

 

Be careful if you decide to go for a bigger pump, the extra pressure can cause leaks from joints, valves and tap washers, etc.

 

As already mentioned, some things have filters which could be blocked. However, things like garden hose taps don't have filters. If you have one try turning it fully on. If you get good flow/pressure then you know that the pump is OK and you might have a blockage or dirty filters.

 

Regardless of the result, good idea to clean all filters anyway.

 

Another thought - some of these systems have ingenious loops and a bypasses - Example 1: to allow the pump to pull water from the mains (illegal but common). Example 2: to send mains water directly to the house (bypassing the pump and tank) so you can still have water during power outages. This one is also common but perfectly legal and very handy.

 

It's not possible to see from your photos whether you have these systems - If there are several valves on the supply side (on the pipework before the tank and pump) you could try different combinations of open/closed to see if there is any improvement.

Edited August 4, 2017 by chickenslegs

[VocalNeal]

I suggest the blockage thing first. Then have a look and see if you can identify where the water enters the tank and pump is connected there is usually a non return valve but you may have a ball valve which is open? Your pump is Ok. You have 25 psi if you go one size up you get about 32 psi. 

[Formaleins]

Have you tried bleeding the pump? Switch off the pump, open a tap as far away from the pump as possible, then open the square drive nut on the bladder / reservoir side of the pump and make sure there is no air trapped.

[hugocnx]

>>Example 2: to send mains water directly to the house (bypassing the pump and tank) so you can still have water during power outages. <<

In this situation, should you not close the main valve if pump is activated?

[Beats56]

Got a new pump this year and it came with a extra spring. I guess this for the pressure. Maybe yours is worn out. Did have a lot of taps that needed cleaning when it was up and running. Little stones or small bits of concrete where plugging off the flow. Took them apart and gave it a good flushing. Problem fixed.

 

[Foozool]

 Check water pressure right at pump output. 

If the pressure is low at the pump output, crack in pipe between pump & tank (Pump sucking air & water both) Most probably. 

if the pressure is desirable at pump output then there could be a broken pipe after the pump somewhere (in ground perhaps). 

Edited August 5, 2017 by Foozool

[flipper2222222]

thanks to all for the suggestions, will make an attempt at some of them. 

Edited August 5, 2017 by flipper2222222

[xtrnuno41]

As you see on your pump it can do 0.5-0.6 l/sec. (31-38 ltr/min divided by 60)

You can take a marked bucket of 5 or 10 ltr .

Open a valve totally and let the bucket fill to marker, MEASURE the time needed to fill to marker starting direct from placing bucket under tap. Ofcourse you can do that on more spots in the house. 

After reaching marker and you measured time , you can calculate the flow. 5 or 10 ltr devided by time in seconds.

Then you know if your pump is delivering right, should be in between 0.5-0.6 ltr/second. 

 

All depends on piping, bends or a blocking in the pipes or ofcourse if the pipes go underground,

you can also have leakage and you are waisting water and flow.

However the pump would be oscillating then when it is not used, unless the leakage is closed in normal position.

If it ever runned well then probably you have a block or leakage. Leakage in probably the way,

returning to vessel. through bypass pipe.

If you have a bypass of the vessel and pump, water passing  directly to watertaps by grid, There should be a

non returning valve in it or a handvalve, otherwise the pump will circulate to the vessel and you loose flow to watertaps.

As you can see in below scheme.

Otherwise the pump is not working right anymore and you need to overhaul or replace it.

If it never runnend well, then still you can have a blocking/leakage or the capacity of pump is too low, doubt that 

However the more bends there are in the system , the bigger powerloss and flow.

 

 

[flipper2222222]

hi list, thanks for all the handy tips, I am out of LOS at present. My wife says the task has been assessed and there are not blockages (professional skills unknown) and that the solution is to buy one of these pumps, see pic.

 

10,000 BHT and 950BHT to fit. 

I may be asking too subjective a question, but here goes anyway. 

does the price seem reasonable and right?

 

do you think this unit will fix the problem?

 

 

[Crossy]

28 minutes ago, flipper2222222 said:

10,000 BHT and 950BHT to fit.

That seems a lot for a LuckyPro (= cheap Chinese) pump, approaching Grundfoss money.

 

Any guarantee if it does not fix the problem (sure there is)?

[Austin Wong]

You home water pump power is not enough. I use 300W pump.