Have water pump but pressure up and down...

[bamboozled]

I do have an electric water pump and holding tank with the pump going on and off when the water is turned on in my rental house. However, the shower in the upstairs bathroom (the location where I am apt to notice these things) has vacillating pressure mostly on the weak side but with enough variation that the temperature of the hot water is impossible to regulate as the amount of water being fed into the heater is up and down. Plus, showering with weak pressure is just simply less enjoyable. Strangely, the water pressure in the rest of the house does not seem to be an issue and indeed is not an issue at the sink faucet in this same bathroom. Rather than call the landlady to attend to this, who will inevitably send her completely inept son-in-law to bang on some blue pipe and make a mess but accomplish nothing, I would like some advice from the good people on Thaivisa. I am no genius but no fool either when it comes to tinkering and certainly less of a fool and with a better work ethic in this regard than the son-in-law. Let me add that the Hitachi water heater is new, bought by me about two weeks ago, and installed by someone else's inept son-in-laws sent by the retailer (in my absence but in the wife's presence). Any takers (tinkerers)?

[noise]

I am fairly sure it is simply a matter that, like you alluded to, someone who did not know what they were doing tried to adjust the settings.  In doing so, they may have lowered the cut off too low.

 

I think most pumps will come with a default 20 psi difference, on at say 30 psi and off at 50 psi.   There should be 2 adjustments screws, one to raise the minimum pressure at which the pump turns on and one to create a higher turn off pressure if the 20 psi difference is not to your liking.

 

I attached a picture of my current pump showing the box in which the control srews are located.   My first pump had a similar box and had the instructions printed in English on the inside.  There is a screw holding the cover in place.   The adjustment screws are (should be) labeled which is which.

 

It is actually a simple process to set the pump.   Get a hose with a sprayer on the end so you can easily turn off and on.   Turn the hose on and, watching the gauge, see at what pressure the pump kicks in and whether or not the pump stops while water is still running out of the hose.  For my house, that meant the cut off pressure was too low as I had the same problem with the bathroom water heater at the other end of the house.   

 

Once  you think you have it set, I advise having some one turn on a faucet in another location while you watch the pressure gauge.  I found enough of a difference between the outside faucets and house faucets to need to tweak the settings.

Edited September 7, 2016 by noise

[worgeordie]

Most likely an air lock in in the pump, which you need to bleed,

loosen the nut* (dont  know you model) but this is what I do with

mine,and let the water and air flow out,tighten nut up again.

 

Or maybe the pressure switch needs adjusting,if you dont know

anything about electricity,better get someone qualified to do that.

are there any filters that  could be partially blocked ?

*nut on top of pump,mine has like a cross on top,to use tool to loosen.

regards worgeordie

[rawhod]

The problem as you describe it, is with the water heater and not with the pump, since the flow variation occurs only at the shower.

(Do not adjust the pressure switch settings on the pump unless you know what you are doing and have a pressure gauge)

 

It sounds very much like a water flow restriction in the shower unit

Disconnect the power from the shower unit before you do anything (at the circuit breaker should be OK), disconnect the shower head and check the water flow through the unit.

 

There could be an air lock in the unit or the shower head.  

Check the setting of the water flow valve on the unit (there should be a small valve on the unit outlet). If this is set too low, the pump will oscillate on and off

Check that there is no debris in the shower unit filter from  installation restricting the water flow.

 

Good luck

[rijb]

Don't forget to check the filter insets in the water heater hoses.

[Dante99]

A lot of advice here without any knowledge of what kind of pump and pressure tank are actually inplace.  There are many kinds and all with different requirements.  Also the location of the holding tank is important, is the house fed from the tank or from the pump?

 

But since the problem seems to only be with the newly installed water heater and the sink pressure in that bathroom is okay, the new water heater would be the first thing to check per Rawhod who covered the issues well.  But again there are many different kinds of water heaters with different flow controls and filters.  Check the users manual for installation and troubleshooting.

 

 

[bamboozled]

Hi all and thanks so much for all the posts. Thaivisa did not alert me to any movement on this post so I thought it had been a dud. I have to edit one part of what I had previously written. The water in the sink in the bathroom does NOT have a lot of pressure. And checking the other taps on both floors with a more discerning eye, I would report that while the pressure is not horrible it is not super high. It is sufficient for washing hands/dishes/etc…As they say in medical parlance, the pressure from these other outlets is "unremarkable" meaning ok. It is in the shower/hot water where "unremarkable" becomes "remarkable" because of the temp fluctuating so much and the lack of pressure in washing away soap. I would not think the new water heater could be plugged but I suppose installing anything new could possibly churn up debris from somewhere in the system that would plug it up. However, that does not in my head explain the fluctuation but could explain simply low output.

 

I have attached pictures of my pump set up. Egads! was this built from left over jeep parts from the war?? No wonder there are issues. Perhaps the adjustment screws are in the box under that coil/solenoid looking cylinder but not sure I want to mess with this beast. It doesn't look people friendly at all. Anybody have a lead on a pump guy…to avoid the Jack-of-All son-in-laws?

 

Has anyone noticed their water pressure way up during or right after a heavy rain? I have and it rather baffles me...

Edited September 8, 2016 by bamboozled

[rawhod]

IMHO...a new pump would be a good investment.

Failing that, a complete strip down, and clean and service of the old pump might help...

 

The towns water supply pressure does vary during the day, however, with a pumped supply, you should have a constant pressure.

If you are getting pressure variations at your taps, it could indicate that the pump is not working.

Have you checked that the pump operates on demand?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[bamboozled]

It does go on when the tap is open but not necessarily instantaneously such as the pump in my last rental house. That one…you just snuck a sidelong glance at the tap and the thing would kick on. It used to annoy me that it was so sensitive but the water pressure was indeed constant. So the tank should be feeding the pump and not the pump feeding the tank, correct? Meaning that the pump SHOULD kick on immediately to provide water pressure, yes?

[noise]

I have to agree with Rawhod.  I would get a new pump.   But you have the problem of being a renter, so .......

 

And, as he said, 2nd choice would be complete strip down and rebuild.  But I think that is a job for a shop and, unless they have a "loaner", you would be without a pump for  XX number of days.

 

This pump says  20 psi on and 34 psi off (I like psi more than kgf/cm2).   I do not know how city water pressure acts in conjunction with a running pump but I will hypothesize that city pressure causes the pump to shut down until pressure drops to 20 psi but your water heater demands maybe 30 psi?   So you get hot water with pump on, cools with pump off, back on when pump comes back on and then you get scalded?

 

Can you look at your water heater and see if it has a label like the pump that tells you what its operating pressures are?  And if there is a minimum flow requirement to compare against the pump's output?   And as I alluded to above, both my old and new pumps had factory set on/off pressures of 30 psi and 50 psi.     I think 20 psi and 34 psi are way too low but I should stress that is for my house with long pipe runs and my pump.

 

Back to a new pump:  if your landlord is amenable, get a pump with a pressure gauge.   

 

 

32 minutes ago, rawhod said:

IMHO...a new pump would be a good investment.

Failing that, a complete strip down, and clean and service of the old pump might help...

 

The towns water supply pressure does vary during the day, however, with a pumped supply, you should have a constant pressure.

If you are getting pressure variations at your taps, it could indicate that the pump is not working.

Have you checked that the pump operates on demand?

 

Edited September 8, 2016 by noise

[bamboozled]

I have the 4500w version but I guess the min/max are the same for all models. …not sure how to convert those numbers to psi. I think the best course is to see what the landlady says, at the same time trying to circumnavigate a visit from the son-in-law. I'm sure she and her husband are aware the pump is from the time of the Lanna kingdom. How much do these pumps cost? Getting a guy to come look at it is probably not that expensive and I might just find someone on my own instead of dealing with the landlady who will try and do it on the cheap.

 

Or this pump might mysteriously suffer some well-placed hammer blows or voltage surges.

[kaptainrob]

Read thru this thread > 

Hope it helps.

[noise]

multiply kgf/cm2 by 14 to get PSI.  You heater will take up to 49 psi.  and the minimum of 2.24 is so low that it effectively would work with any flow.   So your problem of fluctuating temperature seems to me to be a pump fluctuation issue giving you varying amounts of cold water.  

 

I am guessing this is one of those on the shower wall units and that the shower head hose is smaller in diameter than the pipe to the cold water faucet.  So as total flow fluctuates, cold water fluctuates while the hot water flow is constant?  Or something like that?

 

My pump was about 18,000 baht but we own our house and I wanted a visual psi guage to look at as I adjust pressure.  We bought a pump that looks like yours for the MIL who now has a set up like yours.   Very poor flow out of the shower head upstairs because of the small diameter hose, but the temp is constantly the same (water warmer, not heater). 

 

Again, my analysis is based on my experiences and your mileage may differ.  Hope it at least gives you more info to think about.

[Dante99]

51 minutes ago, bamboozled said:

It does go on when the tap is open but not necessarily instantaneously such as the pump in my last rental house. That one…you just snuck a sidelong glance at the tap and the thing would kick on. It used to annoy me that it was so sensitive but the water pressure was indeed constant. So the tank should be feeding the pump and not the pump feeding the tank, correct? Meaning that the pump SHOULD kick on immediately to provide water pressure, yes?

No the pump has a pressure tank so when the tap turns on the water comes from the pressure tank until the pressure drops then the pump turns on.  So it is not immediate.

 

Yes the tank feeds the pump, the tank is fed by city water supply or another pump that is at a well.  You see the water pipe going into the top of the tank to feed it is not from the pump.  You should check to insure that the tank is full or close to full because if it is not you have another kind of problem.  Look down into the tank to be sure there is not blockage on the outlet pipe going to the pump.

 

Now that you have acknowledged that you have pressure problems throughout the house, the pump is the second thing to check, the first being water in the tank.  I have had and maintained Hitachi pumps for 25 years here and never seen one quite like the one in your photos, it appears to be a very very old model and it appears to be leaking but from where is not clear.  Could be you just have a pressure tank problem.  But a new pump is probably indicated and as mentioned above you can get one with a higher pressure/flow rating without much extra cost.

 

Good luck, I hope your new pump does not start blowing your pipe joints.  You do need help.

[Dante99]

1 hour ago, noise said:

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This pump says  20 psi on and 34 psi off (I like psi more than kgf/cm2).   I do not know how city water pressure acts in conjunction with a running pump but I will hypothesize that city pressure causes the pump to shut down until pressure drops to 20 psi but your water heater demands maybe 30 psi?   So you get hot water with pump on, cools with pump off, back on when pump comes back on and then you get scalded?

 

 

 

 

 

 

Totally off the mark.  The city water pressure has nothing to do with the pump or house pressure since the pump is fed from the tank unless of course there is a bypass turned on which feeds city water into the house rather than feeding the house from the pump.  If that is the case, the pump should not be turning on because it is out of the loop.

 

From the photo it appears that you have a bypass but can not see if it is turned on,  is there a valve hiding behind the pots?  IF so it should be turned off to feed the house from the pump.  Also if so, you can remove the pump and feed the house from the city water while dealing with the pump but city water pressure fluctuates a lot.

Edited September 8, 2016 by Dante99

[bamboozled]

Very interesting...! The bypass hose coming in on the left (previously hidden behind the pots) does not have a valve to shut it off. So is it combing with the pump water and possible reducing the workload of the pump and therefore the overall pressure arriving to the house? And yes, it does have a leak which appears to be where the pipe from the tank enters the pump.

 

Noise, you are correct about my water heater, it is as you describe. The outlet tube is indeed a bit smaller than the inlet tube but sometimes when the pressure drops the water barely has enough verve to crawl out of the shower head.

 

I was about to check the level of the tank but it's in the sun and burning hot at the moment so climbing up on it will have to wait.

 

Now to read Kaptainrob's link...

[sappersrest]

Things to check some as previously stated.

 

The float valve inside the tank may be stuck or faulty.

The bladder / diaphragm in the pressure tank has ruptured.

You defiantly have a leak this would appear that in all possibility the mechanical seal is fault this will cause the pump to draw in air.

The capacitor , may have given up the ghost.

The pump impeller may be worn given the age of the pump.

The non return valves may  also be faulty.( you have two fitted one on the flow from the pump, and one from the the  towns water into the tank.)

 

[lj cm]

Your pump looks terrible; buy a new one and for a house with 2 floors get a pump minimum 250 watt.

[Dante99]

40 minutes ago, sappersrest said:

 

 

The non return valves may  also be faulty.( you have two fitted one on the flow from the pump, and one from the the  towns water into the tank.)

 

Good points Sappersrest but the second check valve does not appear to be on the towns water into the tank, it is between the pump and the towns water to insure the pump does not push water down the towns line to other houses or even into the OP's tank making a loop of madness...if that check valve is shot then it certainly should be replaced first.

 

The leak if it is where you think could well cause the pump to suck air which would be a problem.

 

The towns water going into the house 24/7  is an odd configuration, no shut off valve.  So if the towns water pressure is high enough the pump does not come on but when the house demand is up compared to the towns pressure the pump cycles in, in theory. 

 

Questions for the OP:  Did this system ever provide satisfactory pressure?  Did the pressure issues start when the new water heater was installed? Or is the new pressure problem related only to the new water heater? Or the water heater pressure problem exists when other valves are open?

 

Two story house? Three bathrooms?  Pump is too small to feed them all.

 

Rob's reference is worth consideration for sure.

 

 

[bamboozled]

Yup, two story house with 3 bathrooms. The pressure issue has existed since we moved in but seems to have gotten worse lately and there does not have to be more than one tap open to have weak pressure. Even just one faucet open and the pressure is bad. I am going to have my wife call the landlady and at least find out what she has to say. I'll try to keep the son-in-law out of the picture. Or maybe I'll ask the neighbors for the name of their Mr. Fixit. I'll report back what I find folks. You've all been a great help.

[Dante99]

20 minutes ago, bamboozled said:

 I'll ask the neighbors for the name of their Mr. Fixit. 

best first step

[DUNROAMIN]

Knowing now that maintenance in Thailand is a dirty word, looking at that pump I would suggest a new pump. Also take into consideration the lack of qualified or professional tradespeople here. You will get the run around trying to fix it then find if you do get it eventually fix the cost will catch up with a new pump. 

[norbra]

13 hours ago, Dante99 said:

best first step

I would look at the non return valve located at ground level,located prior to the pump input pipe to the house supply pipe ,if this is at fault low town water pressure would start your pump when you are using water,but it would also be applying pressure back into the town water supply,reducing house water pressure. Hope this might be of some use

 

[callaway]

22 hours ago, sappersrest said:

Things to check some as previously stated.

 

The float valve inside the tank may be stuck or faulty.

The bladder / diaphragm in the pressure tank has ruptured.

You defiantly have a leak this would appear that in all possibility the mechanical seal is fault this will cause the pump to draw in air.

The capacitor , may have given up the ghost.

The pump impeller may be worn given the age of the pump.

The non return valves may  also be faulty.( you have two fitted one on the flow from the pump, and one from the the  towns water into the tank.)

 

Float valve faulty...would result in no water in tank. Easy checked. Generally if they are faulty it causes them to leak causing over flowing tank

Ruptured bladder... with that leak the pump would be continuously starting and stopping due to loss of mainline pressure.

Mechanical seal leak...yes very good possibility

The capacitor ... if capacitor has given up the ghost the pump would not start, unless you assist the start by spinning the cooling fan to help

Impeller worn...damn good chance of that

The non return valves... providing the water level in the tank is above the suction side of the pump it would not cause an issue. It would be working as a self priming pump

 

If the heater is new and no issues before then the very first thing to check would be disconnect the feed hose to the heater and check the volume of flow. then re-install and remove the shower head. Check if there is a big reduction in volume then the heater is the issue. As stated before check the wire filters in the inlet and outlet of the heater. Maybe crap in them due to installation. Check also the wire filter at the connection of the hose going to the shower head. Have you changed shower heads and put in a low flow head? Some of the low volume shower heads do not use enough water causing the the pump to cut out on high pressure setting. I think that is where you need to start checking. I am sure one of these things will be your issue.

 

 

Edited September 9, 2016 by callaway

[bark]

Try cleaning your shower head. Could be that some of the holes are blocked. Or there is a bend in the metal shower hose.

Maybe time for a new one.

Also my water pump was 300 watts. Two floor house.  You have only 200, and it looks like it is 20 years old.

[adwbkk]

On 07/09/2016 at 8:37 AM, worgeordie said:

Most likely an air lock in in the pump, which you need to bleed,

loosen the nut* (dont  know you model) but this is what I do with

mine,and let the water and air flow out,tighten nut up again.

 

Or maybe the pressure switch needs adjusting,if you dont know

anything about electricity,better get someone qualified to do that.

are there any filters that  could be partially blocked ?

*nut on top of pump,mine has like a cross on top,to use tool to loosen.

regards worgeordie

You guys are making a small problem big.   From What the OP has written the solution is as posted by Worgeorgie.   There is air in the pump and that makes the pressure switch "spongy".   Crack open this cover and bleed the air out and that should fix it.

[khunPer]

My first thought after seeing the photos is: replace that old pump.

And I would not adjust pressure – that's an expert job and the pressure adjustment-screw often labelled "Do not adjust" – especially on such an old pump.

However, checking the newly installed water heater – if the problem only arise after this installation – is worth to begin with; i.e. is the water flow constant before the water-heater..?

[uptoyoumyfriend]

i think your new shower restricts the flow of water more than the old one and the pump turns on and off more.you could try the shower with the faucet open at the same time so the pump doesn't cut out any more.ultimately it seems you just not have enough pressure and since you are renting you might do what one of my tenents did, you buy a smaller booster pump and and have it installed just ahead of your appartment.

[GOLDBUGGY]

Adjusting the Pressure Regulator to a higher pressure and also increasing the pressure in which your Water Pump starts up again may give you the desired increase flow in your upstairs shower but the is a couple of things to consider first. Usually the Pressure Regulator and the Offset Pressure (the pressure difference between your pump starting and stopping) is Factory Set. So there is usually no need to play with this unless somebody before you did. 

 

The other thing to consider is for example my pump has a built in P.R.V (Pressure Relief Valve) which with send the pump discharge back to the suction of this pump if the pressure becomes too high for this particular pump. So there are limits on how high you can set this pressure. If your pump starts up but won't shut down, you set your Regulator too high. 

 

I would normally think that if you water pressure in low in the upstairs bathroom then you water pump is undersized and needs to be bigger. But if it worked fine before, but now doesn't, then that could be your pump is air locked as someone suggested and to follow his procedure. 

 

But what is most puzzling is that it seems your sink works well in this same bathroom, but not your shower, indicating it is not a flow or pressure problem with your water pump if the water piping is close to the same size to both. I would check you sink again on full flow and perhaps flush your toilet at the same time then run your shower to, and see what happens. That should tell you if it is a pressure problem or a heater problem.

 

If it is a heater problem then the obvious would be a plugged inlet filter, or some blockage in this water line. Or if you recently installed piping to this heater it is too small for the flow you need. It would also help to know what you usually set your heater temperature at for a shower. If it is always at 10 and yet the water gets cool, then the heater you bought is under rated.

 

If that is the case you will need to cut the water flow to this heater by using the inlet heater water flow valve. You will have less water for your shower but at least it should be warmer.     

[williet98248]

Re. your old pump.  I rent as well.  My pump started leaking.  I went to a company that sells and services water pumps and storage tanks.  Arranged for a service guy to come out and check my old pump over.  They replaced all the O rings, gaskets and checked the settings on the pump.  Works fine now.  Cost me 500 baht and well worth it.  They also back flushed my filter set up and washed out a pile of black sediment.  A good service may be all you need on the pump.  As per the advice from other responders you may have to check your water heater as well